Two years ago I installed a pollinator garden in early July. This goes against my recommendation to install plants in the fall, when roots have longer to get established and less stress is felt on the rest of the plant. But I wanted to see what would happen if I was careful to mulch well and keep it irrigated. Oh, and did I mention I was going to root wash every one of them? (Be sure to look at that process in the link from 2018.)
I reported on progress last year, and this year shows even more vigorous growth by nearly all the plants. Two of the three ‘Bandera Purple’ lavender died over the first winter, as they were marginally hardy (USDA 7-10) for our area. One straggler remains in the lower right hand corner of the photo below. The Agastache ‘Acapulco Red’ and the Verbena ‘Homestead Purple’ were planted near the front of the beds on both sides and while they survived the first year, they are now gone. My guess is that our cold snap in February 2019 wiped out those plants that were in less protected locations. Perhaps we’ll fill those spots in later with something more cold hardy, or just let the escaped Viola tricolor continue to colonize bare spots.
Overall, the garden is wildly successful in attracting hummingbirds and a variety of native bees and other insects.
I still have a little work to do – I’m relocating the strawberry adjacent to the southeast garden so it stops invading the perennial bed. But after that I’m calling this garden finished.
Summer is a time of bounty in the home garden. During June, July and August the majority of small fruits ripen on home orchard trees. Plant health care is important to consider in advance of summer bounty. Careful dormant season pruning, dormant sprays, mulching and care helped to produce a nice harvest. As the fruit comes off the tree, some summertime options are available. This is a time when some limited summer pruning can be done to manage the physiology and growth of many fruit trees. Even some citrus will benefit from careful summer pruning.
One obvious reason to prune in summer is to repair broken and remove dead branches that may have occurred from excess fruit weight or other injuries. Breakage is common in peach, plum and apples if fruit loads are not thinned earlier in the season. Cut the broken branch from the stem it attaches to with an angled cut that leaves the branch collar intact. Do not cut branches flush with the stem they were attached to. Many years ago the myth of flush cuts for shade trees was found to permanently damage trees, but flush cuts are often still practiced on fruit bearing trees. Flush cuts allow decay organisms to enter trees leading to heart rot and other kinds of wood decay.
Another myth that persists in home fruit orchards is painting wounds with a ‘sealant’ or ‘protestant’. There is no reason to paint cuts. They do not limit the progress of decay or prevent decay from forming behind the paint. Pruning paints do not promote “healing” or callus formation to close the wound. There is some thinking that pruning paints may even accelerate the process of decay formation. So throw away the black tar, it has no practical purpose in support of pruning.
While pruning paints are no longer used, paint has other functions that can be helpful. If a large branch was removed from a tree, sometimes the remaining branches may require protection from sunlight. Apples and other thin-barked trees (citrus, cherries, etc.) are very susceptible to sunburn. If branches that were previously shaded are suddenly exposed to high light levels, the bark can be destroyed leading to sunburn cankers and entry of disease-causing fungi such as Botryosphaeria spp. If repair pruning exposes a large gap in the canopy, it is appropriate to apply white wash or diluted white latex paint to exposed branches in order to protect them from bright sunlight. The most severe damage occurs on southern and west facing branches. Sunburn is one of the leading causes of abiotic damage and a predisposing factor for disease such as stem and branch cankers in apples.
Fireblight is another common disease on pears and apples and develops after bloom. Pruning out fireblight affected twigs helps to arrest disease progress. Finally, bacterial canker can be devastating to Prunus (plum, cherry, peach, nectarine and almond) in parts of the country with warm summer rains. Immediate removal of bacterial canker affected branches is necessary to prevent permanent damage to the tree. Tools used to remove cankered branches should be sanitized by flame (torch) or with disinfectants. Canker diseases are active in the warm summer growing season. Cankers can be caused by bacteria or fungi and should be dealt with as soon as symptoms are noticed. The earliest symptom of an active canker is slowed growth relative to other branches on the tree. Slowed growth results in smaller leaves and fruit and fewer leaves. Affected branches seem more open and just look “weaker” than their healthy counterparts. Slowed growth is often followed by wilt, leaf drop and eventually necrosis or death of the branch. It is best to remove diseased branches early before the organism spreads to the main stem. Since symptoms occur when leaves are on, summer pruning is the best approach to remove cankered branches. Regardless of where or when damage occurs, using correct pruning practices should be adhered to.
Healthy growth on the tree above but thin, weak, small leaves on the tree below indicate a developing branch canker.
Pruning is used most widely on fruit trees to dwarf them so that fruit is produced at a height convenient for harvesting. Pruning creates two universal responses that apply to all woody plants:
I. Pruning is growth retarding. The part of a tree pruned will grow less than the unpruned part. Or, a pruned tree will grow less than an unpruned tree.
II. Pruning is a bud invigorating process. A pruned tree or branch will have more of its buds released to grow compared to the unpruned branch or tree where many buds remain in a dormant state.
The more a tree is pruned, the less its roots and stems will grow. Even though the more a tree is pruned the more latent or axillary buds will be released to grow, it will not be able to make up for the lost leaf potential of the unpruned tree. The pruned tree has reduced photosynthetic capacity, makes less energy and will grow less overall. The thing that is not very clear is how the timing of pruning affects the basic processes. In his review, Chandler makes clear that pruning in the dormant season will retard the growth of apples less than if they are pruned in the summer. Summer pruning also significantly reduces the growth of roots compared to dormant season pruning. Removing leaves in mid-summer or after all shoot growth has stopped (summer rest period), removes photosynthetic capacity and reduces stored energy in the tree, thus retarding growth overall. While buds may be invigorated and new summer growth may occur, this rarely makes up for the tissue lost and still results in growth reduction.
Summer pruning does not result in more fruitfulness the following year, and in apples does not increase the number of spurs formed for fruit formation. Summer pruning can open the canopy and allow branches to form lower down that are useful for easy harvest. The effect of summer pruning on next year’s fruit quality is uncertain. Summer pruning can accelerate the ultimate scaffolding or canopy shape for the mature tree.
Pruning citrus after harvest, during the warm season can affect fruit size in the following year. This may be due to fruit thinning as some citrus have green fruit formed by summer that ripen in winter or spring. Summer pruning removes fruit and remaining fruit can grow larger.
Summer pruning of fruit trees before fruit harvest increases light penetration into the tree and can increase color development of the fruit. Pruning must be done cautiously to avoid excess light penetration and sunburn to scaffold branches and resultant canker diseases. Summer reduction pruning is most often accomplished by pruning the ends of branches back to other branches or twigs. Removing about one half the current season’s wood (on a given branch) will achieve objectives usually without causing excessive light penetration into the canopy. Not every branch need be pruned but an even approach, removing branches consistently around the tree, will maintain form. No more than 15-20% of the canopy should be removed by summer pruning. On some vigorous growing trees such as Persian mulberry, pomegranate, or some peaches, heavier pruning doses can be used. Pears, apples, plums and cherries require less pruning and cuts should be made to preserve spurs and other fruit bearing wood. Some varieties of cherries can become ‘over spurred’ and thinning cuts to remove excess spur wood can sometimes be helpful to limit production and increase fruit quality in the next season.
Chandler, W. H. 1923. Results of some experiments in pruning fruit trees. Cornell University Agriculture Experiment Station bulletin 415.
Ingels, C. and P. Geisel. 2014. Fruit and Nut Tree Pruning Guidelines for Arborists. University of California Agriculture and Natural Resources publication 8502. http://anrcatalog.ucanr.edu
Saure, M.C. 1987. Summer pruning effect in apple—a review. Scientia Horticulture 30: 253-282
While we can’t ever
control or even predict the weather, in most places it is important to have a
plan on how to deliver water to our home gardens during the hot, dry months of
the summer. Aside from reducing water
need through some good management practices, delivering water in an efficient
and sustainable way is important when planning and planting our home
When there is
scarcity, it is necessary to conserve. Several years I got to see scarcity in
person on a sustainable agriculture tour of New Mexico. Farmers in New Mexico have only limited
access to water from irrigation canals, to flood irrigate their fields, or even
wells for drip irrigation.
This severe lack of
water got me thinking about how much we take water for granted in our own
gardens. We often apply as much as we
want or need in an inefficient manner (using sprinklers, sprayers, etc.)
because we think it will always be there when we turn on the tap.
Where I’m located in
Nebraska we are also blessed to have water falling from the sky. Sometimes
there’s too much, and at others there’s not enough. But that’s much better than
in some places – I visited some parts of New Mexico on a farm tour where they
get seven inches of rainfall in a normal year. Seven. Total.
conserving what water we have means that we are good stewards and are ready for
when issues do arise. And let’s face it, there are some times in the summer
that are dry where water conservation will help reduce using water, which can
also save money.
When we talk about
conserving water, there are two ways to go about it. First, look for ways to
reduce the need for water. Then, look at ways to reduce water waste and usage
whenever you need to use water on your lawn, landscape or garden.
Reducing the need for
During dry times, it
can be necessary to provide water to the garden to keep it growing healthfully
along. However, there are many ways to reduce water loss or increase the amount
that stays in the soil around the plants.
Mulching not only
reduces weeds, but also helps hold moisture in the soil. Having one to two
inches of mulch on landscape beds can reduce evaporation from the soil and
decrease the amount of water you need. Newly planted trees should be mulched
for the first few years to help hold moisture in the root zone as well.
Mulching is also important in the vegetable garden. Using straw or shredded newspaper are simple ways to conserve moisture, beat weeds and even reduce diseases. Note that this is shredded newspaper used on top of the soil for a mulch, not whole sheets applied below another mulch or on top of the ground. That process is called “sheet mulching” and we typically don’t recommend it here at the GPs because it limits air movement into the soil and can disrupt the soil microbiome. Stick only to shredded newspaper as a top dressing. (See the bottom of the article for journal articles discussing paper and straw mulches).
You can use woodchip
mulch in the vegetable garden, but it can be difficult to manage when you are
frequently planting, replanting, or harvesting crops. If you accidentally incorporate it into the
soil, it can tie up nitrogen available to plants and cause deficiencies. As long as you are good at keeping it on the
surface, it isn’t as much of an issue.
Large scale gardens or
farms make use of black plastic as mulches to do much the same thing. Plastic mulches
are typically beyond the scale needed for home vegetable gardens and have their
own set of drawbacks such as limiting water and air movement, but for those struggling
with difficult weeds or with issues limiting manual removal (disability,
limited movement, etc) it may be explored for smaller scale production. There
are now even biodegradable plastic and paper mulches available. Use of these
does require drip irrigation beneath the mulch, as rain cannot penetrate to the
root zone. With the issues associated with them, plastic mulches would be
considered a last resort for all but the largest home vegetable gardens, and
many of my GP colleagues recommend against them for all home garden situations –
but they can have their very limited place in the home garden toolbox. And we definitely recommend against the use
of plastics and landscape fabrics in ornamental beds and landscapes.
Choose plants that
require less water. There are many plants available that have lower water
requirements. Ornamental grasses, Liatris (blazing star), Kniphofia (red hot
poker) and sunflowers come to mind. Most native plants are commonly thought to
have lower water requirements, but this isn’t always the case and natives may
not thrive in altered ecosystems (urban settings or even managed landscapes).
Most bulbs also are water efficient and do not require extra watering, as are
most culinary herbs.
Mowing less often in
the hot and dry summer also can conserve water if you are one who waters the
lawn. I’m not a big fan of watering lawns, since it is such a large water usage,
but I know there are those who prefer to have their lawns lush and green at all
times. Instead, when the summer gets hot and dry, leaving the grass on the
taller side can help it stay green even without water. Many of the grasses we
grow here are cool-season and go semi-dormant in the heat. Stopping mowing when
the heat starts slows down growth and the need for water.
When it comes to
getting water to the garden, there are definitely more efficient ways to make
most common method — using sprinklers — is also the least efficient. It is hard
to direct the water to the right place, and during periods of high heat
evaporation takes up much more water than you think. But there are ways to get
water to your thirsty plants without running up the water bill.
Drip irrigation is probably
amongst the most efficient and sustainable ways to water your landscape or
vegetable garden. This method allows you to apply water directly to plants in a
controlled manner, rather than spraying an entire area with water. Also, since the water is applied directly to
the ground rather than sprayed through the hot summer air, the water is much
less likely to evaporate.
There are a few
different types of drip irrigation systems available. Probably the easiest to install is a drip
tape system. This is a deflated tape
that already has water-emitting slits cut into it. While each slit applies a precise amount of
water over a given time period, the pre-determined regular placement of the
slits makes this system better for plants grown in rows, like vegetables,
rather than landscapes where plants are of differing sizes and spacing. And while it can be used for vegetable gardens,
probably the easiest system for a landscape would be one where there are tubes
you can cut to various lengths and insert controlled drip emitters at
customized locations. Another use for
this type of drip irrigation could be for containers on a porch or deck – you
can easily run the tubing out of sight along a bannister or railing and direct
individual emitters to individual containers.
It all sounds
complicated, and larger systems can be, but there are small and simple kits you
can easily find at many garden centers or online retailers available for home
gardeners to install their own within a matter of hours. You will need to have
some skill at reading directions to install them, but the process is pretty
For information on
setting up drip irrigation for your home garden, check out these great
resources from Extension institutions across the country:
Soaker hoses are a
similar concept to drip irrigation, but instead of small drips these hoses just
emit water all along the hose. Still better than sprinklers, these hoses are
quite a bit less efficient than drip, since you can’t direct the water exactly
where you want it. They are also easy to
apply too-much water to an area since they can emit large volumes. Installation
is pretty simple, though, since you just lay the hose down where you want it.
One great benefit of both drip irrigation and soaker hoses is the application of automation. Using a timer can make it easy to keep the garden watered through the season. Timers can be as simple as a dial to manually run the irrigation for a specified time or fully automatic to run the irrigation for various lengths of time on different days of the week. Some more advanced timers also have rain sensors or soil probes to reduce or avoid running when rain makes watering unnecessary (if you don’t have a sensor, remember to stop automatic running until the soil has dried). And in today’s emerging technology, there are also timers or flow controls that can be automated or controlled from a phone app. The timer that I’m now using at home connects to my Wi-fi, and in addition to allowing me to control and observe the watering status from anywhere in the world, connects to local weather data to automatically set a “smart watering” schedule taking into account rainfall, temperature, wind speed, and other factors.
Another effective way
of providing water to your garden is through water catchment. Water catchment is just a fancy way of saying
that you use a rain barrel. Here you are collecting rain runoff to use in place
of water from the tap. There are some ultra-low-flow drip irrigation systems
that you can use with rain barrels (if they are raised high enough to get water
pressure), but this use is usually for watering by hand. For larger gardens,
the large IBC totes that hold 200 or more gallons can make good water catchment
barrels. Just make sure that if you are
using them (or any other barrel) for fruit or vegetable production that they
are made of food-safe plastic and their previous contents were also food safe. (Check out our guide on Building a Rain Barrel)
Over the last couple of months I started a series on raised bed gardens, focusing on materials and preparation. In this final installment, I’ll focus on maintenance activities to avoid in your raised bed systems and remind you of three things you should always do.
We’ll start with some practices that damage soil structure and function (GP John Porter discussed this in much detail a few years ago). Tilling, once the mainstay of soil preparation for crops, is increasingly found to cause more damage than good. Grinding the soil into a material with the texture of coffee grounds might look pretty, but it’s devoid of the ped structure that allows water and gas to move through easily. It also increases microbial activity by bringing up microbial spores, which release carbon dioxide to the atmosphere as they digest whatever organic material is there. And tilling will increase the likelihood of erosion and compaction.
This is the opposite of what gardeners should want: an
optimal soil has natural structure which might look messy but allows for good
drainage. It’s also more resistant to compaction and erosion, especially when
it’s protected with mulch (more on this later).
Speaking of drainage, don’t be tempted to add gravel or
some other coarse material at the bottom of the bed. The change in soil texture
creates a perched water table, which makes for a soggy planting bed and optimal
conditions for soil-borne diseases.
While we’re talking about unnecessary or harmful additions to your raised beds, let’s not forget the annual addition of compost or other rich organic material. This is a holdover from old agricultural practices and is not warranted unless you have an organic material deficiency. Without a soil test, you don’t have a clue about what your soil has or what it needs. The problems associated with routine amendments are discussed in this peer-reviewed fact sheet, and are exacerbated by the tillage that is often the means to incorporate compost. Likewise, don’t add fertilizers and pesticides unless you have conclusively identified nutrient deficiencies or pest issues.
The last tradition I’d like to see shelved is growing cover crops. This practice originated in the management of agricultural fields, which were otherwise left bare after harvest. Outside of producing some kale or other winter vegetables, what’s the point of planting a cover crop in your garden, when you can protect the soil in other ways? Cover crops require water and nutrients, which eventually will need to be pulled or incorporated. You are forcing your soil system to continue to support plant growth and be subjected to disturbance with the planting and harvesting of the cover crop. Why not let the soil rest over the winter with a nice blanket of mulch? Give it a chance to regenerate its nutrient load while being protected from unnecessary disturbance.
Two of these tips have been discussed many times in this forum, so I’ll direct you to longer discussions of soil testing and mulching. Mulching is not just important for protecting the soil bed after the growing season, but should be used on actively producing beds. A deep, coarse organic mulch will promote water and air movement, moderate soil temperatures, reduce weeds, and provide a slow feed of nutrients throughout the season. You’ll have to wait until your seeds are up to apply it, of course, but try to avoid bare soil as much as possible.
Soil testing is really crucial for any garden, but
perhaps most important in vegetable gardens where harvesting may decrease key
nutrients over time. It will also guide you in identifying potential heavy
metal problems. The money you will save in not buying unnecessary fertilizers
and other amendments will pay for many soil tests.
Sometimes you will need to add material to your existing
beds if you are not using a natural soil. Soilless media (deceptively
marketed as “potting soil” though no soil is to be found) will decompose and
settle over time, leaving you with a sunken soil system. You will need to add
more of the same sort of media to the beds, making sure you mix it in
thoroughly to prevent a perched water table. (This is why you might consider
using a natural soil and avoiding this annual chore – because a natural soil
will not subside over time.)
I have been hiding from COVID-19 in Arizona, but I had to return to Ojai, Ca because I was “noticed” by the local fire department to abate my weeds. I returned to find the Weed Apocalypse (WA 2020). Late spring rains were spaced nicely in California supporting rampant weed growth. So, why did this happen? What can I do about it now? How could I have better prepared for WA 2021 next year?
In May, the days are getting noticeably longer and moving closer to the longest day of the year (June 20–the summer Solstice). Longer days add more photosynthetically active radiation and put plants on a rapid growing phase at this time of the year. If water and soil nutrients are not limiting, this is the fastest growth period for most plants. Weeds have the unique quality that they will grow faster than many garden plants even with less resources. When resources are plentiful, they grow faster still.
One way to prevent the weed apocalypse is to deteriorate the weed seed bank . The “weed seed bank” (WSB) is the amount of seeds stored in soil that are viable. The seed bank is restored each year when weeds set seed and drop them on or into the ground. In some cases the seed bank also includes plant parts such as Bermudagrass (Cynodon dactylon) stems and rhizomes (underground stems) that can lie quiet but, once sufficient moisture is available, they spring into life! So once the weeds set seed, just “whacking” or mowing and leaving the mulch behind does not usually solve the problem as viable seed is added to the WSB. Annual weeds can be reduced substantially if they are controlled prior to seed set.
Weeds are sneaky buggers. They imbue their progeny with germination inhibitors or dormancy factors that delay germination. Some seeds complete their maturation even when they have been cut away from the main plant. This is why weeds always seem to be there for you. When dormancy factors wear off, or are washed away seeds will germinate. So after a strong rain event or irrigation weeds emerge that were previously dormant. Some of the seeds remain dormant in the WSB as a back up opportunity to grow. In the case of Slender wild Oat, Avena barbata, it has two maturation ‘stages’ that take advantage of both early spring and late fall rains, with seed ripening at both of those seasonal times. Light is also necessary for many weeds to germinate. When weeds are removed by tilling or digging, new seeds are brought to the surface and may now germinate. Additionally, many weeds have the capacity to regenerate if the entire root is not removed. One tenacious weed, Field bindweed (Convolvulus arvensis), is known to regenerate from each node and root as deep as four feet. Cutting the plants into pieces makes more of them!
Weeds can be annual biennial or perennial . Some weeds such as Poa annua or annual bluegrass complete their life cycle (seed to seed) in only a few to several weeks, others grow for years. Annuals survive drought or cold winters as seeds while perennials as roots, tubers or dormant stolons or stems. Biennial weeds usually grow their vegetative body in the first year and reproductive structures in the second year, they are often rosette forming plants that grow close to the ground in the first season and develop tall stocks in the second. Knowing how to identify weeds helps to understand their biology and ultimately control strategies.
Many gardeners are herbicide averse. However, herbicides will often give the most economic and effective control of weeds. Some weeds like field bindweed are only well controlled with herbicides. Herbicides are broken down into two categories: pre-emergent herbicides and post emergent herbicides. Pre-emergent herbicides inhibit seed germination or kill emerging seedlings before they can develop. Post emergent herbicides kill weeds after they emerge from their seeds. Almost all weeds are better and more easily controlled at juvenile life stages. This is true for mechanical or chemical control. Regardless of how you choose to deal with the WA in your garden starting when weeds are small will give you a tremendous advantage.
Like all pesticides, herbicide labeling must be followed carefully to apply the right amount of product at the right time to the target weed (which also must be listed on the label). There are some amazing herbicidal tools that can save hours of labor. Some drawbacks of herbicides are that they may be expensive, may require multiple applications, require equipment to apply as well as personal protective equipment. Herbicides can be selective or broad spectrum. For instance, Fluazifob-P-butyl (active ingredient of Fusilade II) will control warm season grasses in many ornamental broadleaved plants. This is immensely useful since you can apply Fluazifop-P-butyl “over the top” of a flower garden and free it of bermudagrass (Cynodon dactylon) without harm to your ornamental garden plants or other non-grass landscape plants. Other herbicides containing plant growth regulators such as 2,4-D are broad-spectrum and will kill or harm many kinds of broad-leaved plants in turfgrass without harming the turfgrass. There are also some broad spectrum contact herbicides made of soaps or acids that will kill both broad leaved and grass weeds on contact. While these products do not have systemic action they can be very effective on both cool and warm season young weed seedlings. Herbicides when used carefully and following labeled instructions can save hours of hand weeding labor.
In my own yard I have chosen not to use herbicides because I have so many plants that are sensitive to the kinds of products I would need to use. I am pretty much down for other types of control. This month my city council decided to ban the use of gasoline powered lawn mowers–my chief weapon for the WA! We took a chance and used it anyway because our weed issues are so bad. As mentioned earlier the best time to use mechanical control of weeds is when they are in the cotyledon or two leaf stage of growth. A quick attack with a scuffle hoe will wipe them out. When they grow to adult weed size, larger and larger machinery become required.
Once perennial weeds such as bindweed grow a bit they become impossible to control with hoeing because they will grow back from roots. String line trimmers are used for weeding in many apocalypses but have their limitations. Bits of plastic trimmer line break off and pollute your landscape. Biodegradable plastics are usually used, but the idea of littering your yard with plastic bits is bothersome. Limiting the use of oil consuming machines is a great idea, but using battery powered machines has limits. Buying extra batteries so you can destroy while you charge is helpful.
Hand pulling is a great way to release pend up stress (of the human not the weed), get exercise, and rid the garden of apocalyptic pests. However, for some weeds like yellow nutsedge (Cyperus esculentus) you will only increase the problem as nutlets are released from dormancy when you pull the “mother” plant. By the time you see the emerging nutlets they have formed more nutlets so you can never get ahead of the problem. If you decide hand pulling will work, irrigate the day before you want to weed and they will come out much easier.
Mulching with fresh coarse arborist chips is a great way to prevent annual weeds from getting the light they need to germinate. Mulches also break down to improve soil. We have been mulching for a couple decades on my driveway but have not added any mulch for a few years. The broken down mulch and improved soil are now the most apocalyptic weed garden. If you use mulches for weed control fresh chips need to be applied at least annually in a thick layer to be effective. Also constant application of mulches can make soil! This soil builds up without you realizing that the root collar of perennials or trees may be getting buried. If you mulch consistently around trees be sure to keep the root collar exposed.
Not all weeds germinate in the early winter. There are winter and spring or summer germinating weeds. The differing timing of their emergence can happen unexpectedly. Just when you thought you had weeds in control, another set seems to appear requiring your attention. Look for summer emergent weeds when night temperature lows are above 60F.
Solarization is another way to kill weeds. This is the old greenhouse effect used as a weed weapon. Clear plastic laid on the soil surface and sealed at the edges will if exposed to full sun heat the contents to the point of their death. The solarization effect does not penetrate deeply into soil, so if perennial weeds are solarized, they may survive and regrow from root pieces. If you want to try solarizing your weeds purchase thick UV resistant plastic otherwise you will have bits of plastic everywhere as the sun breaks it down into pieces… Warning, this does not work with Field bindweed! In my own yard I have used old glass shower doors to solarize the soil.
Finally if all else fails and the WA is bearing down, you can just eat them. Many weeds are edible and can make good food. Nettle, Sonchus (sow thistle), purslane, dandelion and many of the Mustard family are edible at various stages of their development. Some folks have even collected mustard seeds and made their own condiments. Of course, you should always exercise caution when consuming wild foods. Some contain toxins or other chemicals that individuals may be sensitive to. The Sow thistle and wild lettuce (Lactuca spp.) contain latex which many are sensitive to. The stinging nettle has hairs on its surface that contain an irritant (oxalic acid) that causes skin burning and welts. Others, such as black elderberry may contain cyanide alkaloids in the green tissues-stems, fruit and other parts. Research the risks of consuming or contacting some plants before attempting to eat or handle them. There is hope, because even the nutlets of one of the worst weeds (yellow nutsedge) are edible…
Now that much of the world’s attention is focused on
limiting the spread of pathogens, well one pathogen, it seems like a good time
to talk about some of the questions or concerns we’ve seen regarding vegetable
gardens, community gardens, and farmers markets. It’s a good time to talk about some of the
practices that we should be doing to prevent other human pathogens from
handling produce, like E. coli and Salmonella, and how those might fit into
preventing the spread of COVID-19.
First things first
First off, we have to remember that SARS-CoV-2, which is the virus that causes COVID-19, is not a food borne illness. I repeat: COVID-19 IS NOT A FOOD BORNE ILLNESS. This means that it is not spread through the consumption of contaminated food like E. coli and Salmonella. I’ve seen many instances of people spreading fear about food online, with many suggesting using soap or bleach on food to minimize risk. Those steps are both unnecessary an actually pose a poisoning risk. There is currently no evidence to suggest that COVID-19 is transmittable by food or food packaging.
The risk from food (which is considered minimal by experts)
is from cross-contamination from food or packaging onto hands or onto surfaces
that are then touched by hands. The
virus would then have to go from a persons hand to mucous membranes in the
respiratory system by something like touching your face or picking your…..well,
we won’t go there. The best defense
against this isn’t necessarily sanitizing all the food you buy, but washing
your hands after you handle it and sanitizing any surfaces that packaging or
shopping bags touch.
But while we’re on the topic of pathogens and food safety,
it’s a good time to talk about some general guidelines that can not only help
stop that potential SARS-CoV-2 cross contamination but also food borne illness
Minimizing the risk from produce even further
Whether you grow it in your own garden, buy it at a local
farmers market, or purchase it at the grocery store, produce has a minimal risk
when it comes to COVID-19.
To minimize the very small risk of cross-contamination even further and (probably more importantly) to also reduce any risk from common food borne illnesses, proper washing of the produce should be practiced. But do you know how to do that? Maybe…and maybe not. Here are some steps to help out.
Wash your hands. The most common pathway of contamination for produce is from human touch.
You should use clean water that you would use for drinking (like out of the tap) and not use any bleach or soap.
Providing gentle friction with your hands or a produce brush or by rubbing the produce together is sufficient.
If you’re washing a lot of produce at once, say from a large harvest, and you’re using a tub full or sink full of water to wash multiple “loads” of produce, keep an eye on how dirty the water gets and refresh it when it gets discolored. Remember that washing produce in a tub or sink of water can also present a cross-contamination issue where contaminated produce contaminates the water.
When in doubt, discard produce you may think is contaminated or wash it separately.
To reduce risk of cross-contamination, consider a “single pass” washing technique where you spray the produce with water and it doesn’t sit in water with other produce.
Food Safety in the Garden
There are a few things we can do in the garden to help stop
the spread of human pathogens. Most of
them are common sense things that most people don’t even think about. Devout GP readers may remember my little
missive around this time last year about the food safety risks of using manure
in the vegetable garden (See: The
Scoop on Poop). Beyond those musings
on manure, though, gardeners can take some additional steps to reduce potential
contamination. Those are:
Wash your hands.
I know it sounds simple, and maybe even more so now that it has been
drilled into our brains, but washing your hands before you garden is one of the
best ways to reduce the spread of pathogens.
It is especially important to wash your hands before you harvest produce
or handle harvested produce.
Use clean containers for collecting and storing
produce. Using harvest baskets, tubs,
and totes is common, but the ones that are best in terms of food safety are
those that can be washed and sanitized.
This is one tactic that many farmers are encouraged to use as well. Plastic tubs, totes, trugs, and crates are
probably best as they can withstand washing and the use of a sanitizer like
bleach. Wooden or woven baskets may be
cute, but they’re harder to clean and can hold on to pathogens.
Look for signs of wildlife in the garden. Aside from eating more than their fair share
of produce, wild animals can also present a food safety risk especially from
their droppings. Look for signs of
animals in the garden and especially take note of any droppings. Don’t harvest produce that has signs of
droppings on them. Many of the big
produce recalls over the last decade have been a result of wild animals like
birds or wild hogs.
Keep pets out of the garden. As much as you like to have Fluffy or Fido in
the garden, they present a risk just like wild animals do.
Wash produce using proper techniques (previously
Best practices for minimizing COVID-19 risks at Community
Gardens (and Farmers Markets)
One other aspect of gardening that could provide some risks for the spread of COVID-19 are the more social aspects of gardening, such as community gardens. I’ve had several local gardens reach out for best practices relating to minimizing risks in the garden – from handwashing stations to shared tool use. Thankfully, NCSU Extension was quick on the draw with resources for lots of aspects of the food system in terms of reducing risks from COVID-19 and they graciously allowed other universities to distribute these resources. Below are some links to the resources that would be helpful to gardeners:
Nearly every afternoon for the last two months, curious
drivers have noticed two people meandering through a pasture, following a
narrow pathway formed by two lengths of string tied to fenceposts. It’s us!
Thanks to COVID 19, we are no longer able to go the gym for a workout so like
many other gardeners we have put that unexpended energy into our gardens and
landscapes. And in this case, cattle pasture.
The lettuce from hell
My family has raised free-range, grass-fed beef cattle for over 50 years, and with our move to the family farm in 2017 we now oversee much of that business concern. Managing pasture weeds is just one of the battles associated with providing quality browse for the cattle. Inedible plants like bull thistles (Cirsium vulgare) and tansy ragwort (Senecio jacobaea) are taprooted species, easily removed with a single weeding. But not Canada thistle (Cirsium arvense), colorfully and accurately described as the “lettuce from hell” thistle. Though it’s highly nutritious, the prickles are so unpleasant to sensitive muzzles that cattle avoid it.
This aggressive, herbaceous perennial (native to Eurasia, not Canada!) has an extensive underground root system, consisting of thick, propagative roots which give rise to more roots (which grow vertically and horizontally), and shoots which pop up seemingly everywhere. They do NOT have rhizomes, and they do NOT have stolons. Apparently, Canada thistle has a unique, hellish morphology allowing it to spread rapidly – 6 meters per year in the U.S. – if not managed (you can read more about this topic here).
Applying plant physiology in the field – literally
But there is a weakness in this aggressive root system – and
that weakness is the need for resources provided by the aboveground thistles. The
perennial root system stores resources over the winter, then pumps them into
new shoots in the spring. This is the chink in the armor – these shoots are
USING resources, not providing them, until they slow their own expansion. So
the trick is to remove the shoots as soon as they appear, forcing the roots to
expend more resources to make more shoots, and so on.
So this is why we are in the field, every day, removing
those shoots, systematically clearing areas and then repeating in another week
or so as new stems appear. And it’s working. But here is the lesson we are
learning that gardeners can apply to their own gardens and landscapes.
We have two weeding implements: the “winged weeder” and the
“uproot weeder.” The first is my choice, though it is NOT a solely a “stand up
tool” for this purpose. My husband prefers the uproot weeder, which twists and
pulls out a core of soil along with the root. I don’t like this latter method,
as it creates a hole through which sunlight can penetrate, activating both
photodormant seeds and stem regrowth. But to each their own.
However, we found another reason that the coring method
doesn’t work well: those cores can stay moist and guess what? The stems
generate new roots, and left alone could easily re-establish if conditions were
cool and moist. Just what we need.
My preferred method, using the winged weeder, is to break the underground stem off as deeply as possible and then work it out as seen int he video. For this you need protective gloves, but not thick ones. You need to be able to feel what you’ve got a hold of.
Hold onto the base of the thistle gently and as you work the weeder under it move your fingers down BELOW the crown. It feels like a tough bulge and you want to hold onto the smooth stem below it. Otherwise it is likely to break off, leaving the crown viable. You will hear, and possibly feel, a satisfying pop as you dislodge the stem from the underground system. Pull it up carefully. The remaining hole is tiny, and easily covered by pressing on it gently with one’s boot.
The advantages to physical removal of perennial weeds
I’m getting out into the fresh air and have lost more weight in the last month than I lost going to the gym in the past year.
I’m controlling a noxious weed population without the use of chemicals.
I’m developing a technique that can be applied to ANY herbaceous perennial in ANY garden or landscape. That’s the great thing about plant physiology – the pattern of resource allocation is not species dependent. Think horsetail and bindweed, for instance.
Do keep in mind that perennial weeds are perennial problems! We aren’t EVER going to have a thistle-free field, but it will become a more manageable problem as the infestation will have been dramatically reduced this year. I’ll try to do some updates over time.
Last month I started a series on raised bed gardens, focusing on materials and designs. Today I’ll mention some of my favorite tools and materials for putting everything together and getting ready to plant.
Getting your soil ready for raised bed use
Tools and materials:
shovel, wheelbarrow, tarp, soil screens
If you’ll recall from my previous post, I like using native
soil for raised beds (assuming it is not contaminated with heavy metals or
other undesirable chemicals). We have glacial till soil, which means it has a
LOT of rocks of various sizes. The bigger ones are easy enough to lift out, but
what about all the other ones?
First, realize that SOME rocks are no big deal. In fact,
they are important in reducing soil compaction. Finely sieved soil, especially
clay soils, will be more prone to compaction than a soil with small pebbles
scattered throughout. But the larger rocks are a nuisance.
For the first pass through, I have found a plastic crate to
work really well. It’s lightweight and the holes are large enough to let soil
move through quickly, while retaining larger rocks. I like the milk crate size
as it’s easiest to handle. Just set the crate in a wheelbarrow or on a tarp,
fill it full of rocky soil, pick it up and shake.
The rocks left in the soil for the most part are easy to
work around, and you can always pick out the larger ones as you go (my personal
choice). Or if you want to give it another screening, you can build wooden
frames with different gauges of hardware cloth, or chicken wire, to remove more
of the rocks.
This is a time-consuming process, but the benefit is that
you don’t have to top off your beds every year. Your native soil will not be
subject to high levels of decomposition and subsidence as will many commercial
topsoils with their high organic content.
When you’re ready to fill your beds, be sure to add more
soil than you think you will need. It is going to settle, and you may need to
add a little more the second year to bring it back to your desired level. But
you shouldn’t have to add any more in the future.
Throughout the soil preparation process, be sure to work
when the soil is dry, or no more than just damp. Working wet soil is difficult,
and wet soil compacts.
But what about heavy clay soils?
Unless you’ve done a soil texture test, you really don’t know what you have. So before you take another route, make sure you really have a heavy clay soil. If it’s just compacted, then proper mulching will solve that problem too. If it’s truly a heavy clay – let’s say over 40% – then yes, this soil might not be best for a raised bed. In that case, I would suggest finding a different topsoil mix, where clay is no more than 30%. Lay down a membrane to keep this soil separate from your native clay soil. Your raised beds will now function more like giant containers, and you will have to make allowances for drainage along the sides of the beds.
Your beds are ready – how to keep them that way before planting
Tools and materials:
coarse organic mulch, wheelbarrow, mulch fork or shovel, rake, soil temperature
Once your beds are filled, it’s important to get them planted as quickly as possible to prevent continued erosion of that bare, loose soil by wind and rain. If you aren’t immediately planting, then you need to cover the soil with a protective mulch. The only choice you have, if you wish to keep your soil environment hydrated and aerated, is to use a coarse organic mulch. Sheet mulches are not advised since they will interfere with water and air movement. Even if you don’t have plants in the soil, there are microbes and beneficial animals that need a constant influx of oxygen and water. A coarse organic mulch, installed to a depth of at least 4 inches, will facilitate water and air transfer and also keep weed seeds from germinating.
If you’ve been following my posts over the years, you already know I’m going to recommend using a wood chip mulch. Its benefits to soils and soil life is well established and it is easily moved once it’s time to plant. But you can use pine needles, straw (not hay!), and other coarse organic materials for this purpose. Fine textured organic materials like compost should never be used as a mulch, as thick layers of compost are more restrictive to gas and water movement and also facilitate weed growth. Save compost for a thin topdressing when your soil anywhere on your property is in need of organic matter, and be sure to cover it with woody mulch to keep those weeds out.
While waiting for the right time to plant, consider
purchasing a soil thermometer. They are inexpensive and easy to use. Good publications on growing vegetables will
tell you what the soil temperature should be when you plant: planting too early
can lead to reduced seedling survival. And while you are waiting you can
install a rain gauge nearby, so you can monitor irrigation needs throughout the
Next time we’ll discuss the dos and don’ts of raised bed
maintenance during the growing season and before planting the following year.
Most of these practices are adaptable to traditional vegetable gardens, so be
sure to check it out!
The concept of sustainable agriculture is not new and the idea of sustainable gardens is likely just as dated. Sustainability as a concept can be applied to soil, farms, gardens or life in the biosphere. The second law of thermodynamics says that all systems tend toward thermodynamic equilibrium where there is maximum entropy (randomness). In functional ecosystems equilibrium is achieved to a degree, and plant, animal and other species are at stable levels. Ecosystems evolved over millions of years to develop connections between individuals creating support networks, predator-prey cycles and nutrient cycles. Inputs are adequate to “sustain” the system and outputs are all recycled. When we create our gardens we are setting up a system that we maintain through inputs and we appreciate the outputs, and it keeps us interested and involved in pushing back the entropy. In almost all cases gardens are not natural systems and if left untended will become more random, weeds will grow, poorly adapted plants will be overrun and the balance will change to something matches the inputs and outputs of a sustainable system as dictated by the location/climate/soil, etc.
The key to a sustainable garden is understanding inputs and outputs and the flow of energy in your system. The reason I like pristine ecosystems is that I don’t have to add inputs to them to take part in their beauty. As long as I don’t interrupt what is going on by breaking connections between organisms unwittingly, the system is self sustaining. Imagine the garden of Eden that always bears fruit and flowers with no inputs from you the gardener. You just walk into the garden and bask in it sbeauty occasionally eating some delicious item you find there. Well we all know that our own circumstances are far from this reality. Getting a garden to provide the aesthetics (beauty) or food (both outputs) often requires us to provide heavy amounts of inputs. Inputs are mostly energy in the form of kinetic or work energy of the gardener, hydrocarbon energy in the form of electricity to run gadgets or fuel to power mowing or clipping equipment, or fertilizers which may be derived from fossil fuels or from the sun as by products of plants. Energy is also the main input into plant systems that may be in your garden. Light contains the energy for their growth. Finally cash money is easily converted to all forms of energy. You can purchase labor, fertilizer, any number of garden amenities bypassing the personal output of your own kinetic energy. Or you can garden smarter and avoid large energy inputs by creating the sustainable garden…
So how do we get a sustainable “Garden of Eden”. First, recognize that not all gardens are the same; they have different functions and purposes. Some are for aesthetics only. Some are for food production. There is a wide body of research that shows gardens and green environments sustain our health; both physical and mental (this would be an output). So a garden is not sustainable if it does not appeal to you or produce enough food or sustenance to justify the inputs. Gardens are like checking accounts in a way; we put in deposits (inputs) and we withdraw benefits (outputs). If the amount of inputs generate the required outputs the garden is sustainable. So since money converts to energy and labor the more money you have the more complicated and detailed your landscape or garden can be, but entropy will have its way with this kind of garden with out extensive inputs. Water thirsty plants, greenhouse cultivation, weed and other pest control, poorly adapted plants and wide swaths of turf all require greater inputs.
-Increase Hardscape Hardscape includes landscape elements such as walkways, walls, boulders, patios, sculptures, small out buildings etc. Since hardscape is not green or growing it uses no water, requires no pruning or other tasks to maintain. Installing strategic hardscape can improve the appeal and functionality of a landscape while cutting down on the sustainable square footage that you are maintaining. It is often wise to consult a landscape designer or architect to optimize the uses and functions of your garden.
-Mulch Mulch Mulch Fresh mulch from chipped tree trimmings is essential for a sustainable landscape/garden. Fresh wood chips are the best source of energy for microbes when used as a surface mulch. Wood chips layered four inches thick over bare soil will improve many aspects of soil, essentially making the soil more “sustainable” for your garden by conserving moisture and adding nutrients over time (for more on mulch see the paper by LCS referenced in the GP site). Fresh wood chips are best around perennials but can also be used as walkway material in vegetable gardens, as mulch around berries and fruit trees and around perennials like rhubarb and asparagus. A well mulched garden uses less water and, in time, requires little or no fertilization.
-Maintain Light Sunlight is the main energy input into your garden and is necessary to sustain the plants growing there. Plants that are adapted to full sun when shaded out by growing trees, shrubs or other tall plants become disease prone, produce less fruit, and are less attractive. To keep vigor up, ensure that plants get enough sunlight by pruning back intruding branches from nearby trees or other shade providing plants. Remove trees that have outgrown their space in your garden and replant with size appropriate specimens.
-Use Enduring Plants Grow what grows well for you. Time spend on poorly adapted and fussy plants will decrease the sustainability of your garden and increase the necessary inputs of time, labor and energy. For oranamental gardens use enduring plants. Flashy annual plants look good for a few months but require replacement regularly. Long lived perennials used as specimens in a garden add value over time with little care, pest control or fertilization. I term these ‘enduring plants’. Enduring plants grow slowly but live long lives. For those who grow food vegetable gardens are a necessity and plants are mostly annual, however perennials are also an option. Rhubarb is an enduring perennial, berry vines, fruit trees, asparagus and grapes provide food year after year with low maintenance relative to annual crops. Keep fussy, pet plants to a minimum, and in containers so they can be moved when necessary to accommodate their needs.
-Recycle Reuse Gardeners spend a lot of energy clipping, removing and throwing away unwanted yardwastes. Consider composting trimmings and weeds and recycling these materials back into the garden. This reduces energy spent processing these materials and decreases the cost of purchasing organic materials for your garden. Lawn clipping, leaves, and tree trimmings (when shredded) can make a high quality compost if carefully produced. Many extension offices have publications on home compost production.
Study of natural ecosystems provides an interesting window into sustainable landscapes. Plants grow with each other in a balance or harmony that results in a sustainable landscape. In these natural settings, litter accumulates under tree canopies (think mulch in your garden) providing a continued source of biological and mineral motivation for soil to be productive. Annual plants grow each year where sun is abundant and shade loving perennials inhabit the understory of trees. The right plants in the right place create a beautiful environment.
Ever since humans started gardening and farming, the practice has had central importance in our lives. As we processed out of the agrarian age, some of us humans may have lost the connection to the importance of growing plants to our everyday lives. We rely on the growing of plants to feed us, to produce medicine, clothing, and shelter. We use plants to provide beauty in our landscapes and our homes. And perhaps one of the positives of the current pandemic is that many people are turning to plants as a way to assuage their fears. Being one of those extension people whose mission is to teach people gardening I’ve seen some of this first hand. But a phone call I received this week really drilled into my soul how important plants are not only for the food they provide, but also the way they effect our mental well-being.
But lets get back to the phone call…. Gardening and plants also have a positive effect on mental-well being in a general sense. The act of gardening can produce a meditative like practice (unless you’re cursing at weeds or violently ripping out diseases plants – but those acts may provide catharsis). But research also shows us that just seeing nature can have a calming effect on our minds.
This was so apparent in my recent call. I had received a voicemail from an elderly gentleman that asked for a call back as soon as possible so that I could talk to his wife (we’ll call her Barbara). I had time between back to back Zoom meetings, so I called. The gentleman answered and after I introduced myself he told me that Barbara had a question about flowers. After a few seconds, a frail, halting voice asked me if all the tulips and daffodils were dead. Over the previous few nights temps had dipped below the normal lows and many plants had seen some damage, including flowers of many early season bloomers.
I answered briefly that some of them were likely damaged, that the blooms would be killed but the plants would be OK. What happened next….I didn’t expect. Full on, gut-wrenching crying. The kind of sorrow that you can feel throughout your being. After a few seconds, between the gasping sobs, she uttered the words “I don’t think I can take it anymore. First we can’t see people. Now the flowers are gone.”
After the initial jolt, I tried to respond as I’ve been trained to do (we have luckily received training in mental health first aid to help clients who are in distress) – calm reassuring words, asking if she was OK, and providing positive affirmation that once the temperature warmed up there would be blooms again. Though she was so overwhelmed that she just said goodbye and hung up.
I was shocked. It took a few minutes for me to compose myself. I don’t often deal with clients where there is such an emotional response (hats off to my entomology colleagues who have to deal with telling people that they have bedbugs or that they might be suffering from delusory parasitosis). After I gathered my thoughts, I felt that I needed to call back – the emotional response was so strong that I wanted to make sure there wouldn’t be issues of self-harm or other effects.
In my return call, Barbara and I discussed that there would be more flowers once the weather warmed back up. We discussed our mutual love of plants and how they make us feel. She sees the flowers in the neighborhood when they leave their small apartment for errands and it makes her feel better. And even though there were still tears, both of us were in a much better place. Out of the blue, I asked if it was OK if I brought her flowers to enjoy until the weather warmed up. At first she was hesitant – she didn’t want to cause trouble. But after I assured her that making sure she had flowers would do me just as much good as it would her, she and her husband agreed. I told them that after I got done with my work for the day, I would find some flowers and drop them off on their doorstep.
I needed to make a (now infrequent) run to the store for necessities any way, so while I was shopping I picked up a potted plant at the grocery store (the one I thought would be easiest to care for). I went home and wrote a note, wrote down some simple directions, and delivered the flowers. As I walked away, I heard Barbara’s husband open the door and tell her that there was a surprise for her.
I have to say that I can totally understand this reaction that may seem excessive to some. Many people are dealing with the stress of the pandemic, some better than others. Here was one thing that was giving this lady enjoyment – seeing the flowers blooming when she is able to get out of the house. And that one enjoyment had been taken away by a late freeze. It drove home to me the fact that gardening and plants are essential for many. For the food that they can provide, both for nourishing our bodies and for nourishing our spirits. Plants are providing us hope for the future and calm for the present.
While I may never hear back from Barbara and her husband again, I can tell you that making that one connection through plants was definitely a boost for me. My wish is that those flowers give her hope for the future. A sense of calm knowing that one day things will return to normal, and the knowledge that one day soon the flowers will indeed bloom again.