The Garden Professors™

Native vs. nonnative – can’t we all just get along?

Probably the most contentious gardening topic I deal with online is the native vs. nonnative plant debate. This, unfortunately, is a debate that is more based in emotion than science, and I don’t intend to stir that pot again. We’ve discussed it on this blog before (you can find a list of them here), and I’ve published both a literature review and a fact sheet on the science relevant to tree and shrub selection. What I want to do in this post is compare two research papers, both in peer-reviewed journals, that come up with dramatically different conclusions.

The first has been getting a lot of publicity on the web and in social media. It was published just two days ago, but because of widespread PR prior to release it appears over 37,000 times in a Google search. The title – “Nonnative plants reduce population growth of an insectivorous bird” – and much of the prerelease publicity about the article spells doom and gloom. It’s a message that gets traction.

The second was published a year earlier and is entitled “Native birds exploit leaf-mining moth larvae using a new North American host, non-native Lonicera maackii.” It appears 194 times in a Google search, even though it’s been available for over a year.

The reason I’m singling out these two articles is they have completely different messages – and one of them is not being heard as loudly as the other. The first focuses on a single bird species, the Carolina chickadee (Poecile carolinensis) and its diet in urban landscapes. Their conclusion: “…properties landscaped with nonnative plants function as populations sinks for insectivorous birds.” Thus, any gardener who happens to use introduced ornamental plants in their landscape is made to feel guilty for starving their insect-eating birds. (As an aside with my manuscript reviewer hat on – this statement has no business being in an abstract as it overextrapolates the research on one species to include ALL insectivorous birds.)

Carolina chickadee (Poecile carolinensis)

Black-capped chickadee (Poecile atricapillus)

The second article has a different focus. It reports the feeding of black-capped chickadees (Poecile atricapillus) on the larvae of a leaf-mining moth (Phyllonorycter emberizaepenella). While leaf miners are common food items for chickadees, the point of this article was to document the host of the leaf-miner – a nonnative and particularly invasive species of honeysuckle (Lonicera maackii).

Honeysuckle leaf miner (Phyllonorycter emberizaepenella)

Chickadees as a group are particularly adept at finding and consuming leaf miners, whose tunnels normally protect them from insectivorous birds. Chickadees move along branches,“examining leaves both above and below them; the chickadees sometimes scanned by hanging upside-down.” This makes it easier to find and extract leaf-miners, as the underside of the leaf is easier to tear open than the surface. And in fact this behavior is reflected among other species of chickadee and leaf-miner: “Similarly, in 15 years of study, Connor et al. (1999) never observed species other than Carolina chickadees (Poecile carolinensis) feeding on the larvae of the gracillarid Cameraria hamadryadella [oak leaf miner].” While these are not the same species of leaf miner studied in this paper, the point is that chickadees eat leaf-mining insects. And leaf-miners can obviously adapt to new food sources, including introduced plants. This is basic ecological science.

Oak leaf miner (Cameraria hamadryadella)

Neither Craves’s article (the second of these two articles) nor that by Connor et al. (cited within Craves’s article) are cited by Narango et al. (2018 – the first article), even though both are certainly pertinent to the topic. But they don’t fit the narrative – which is that introduced plants are not good food sources for the insects that chickadees eat. So they are left out of the discussion, which by default is now biased – not objective. Not science-based.

And I don’t have a good answer to the obvious question – which is why we continue to demonize noninvasive, introduced plants in the absence of a robust body of evidence supporting that view.

Grow Garlic – Keep the Neighborhood Vampires at Bay

While most of those gardening tasks are coming to an end, in most parts of the US it’s time to think about planting a few things in the veggie garden to bring a flavorful bounty next year – garlic (and a few related alliums).

I often reference Halloween and vampires when I talk about garlic, not just because traditional lore says that garlic repels vampires, but because it is a good reminder of when to plant garlic in the garden. October is the prime time for adding the alluring allium to the garden. You can also remember that you plant garlic during the same period that you plant spring flowering bulbs.

Why do vampires hate garlic?

Yes. Vampires are fictional (unless someone finds some empirical evidence of their existence, since you can’t prove a negative 😉 ). These bloodsucking creatures of folklore may actually have a basis in fact that could explain their aversion to garlic. Way back when people didn’t have science to understand things, they often invented explanation for things that were supernatural. Sometimes these explanations may have actually had some truth to them.

In this case, the symptoms of vampiricism could have evolved from the symptoms of porphyria – a set of rare disorders of hemoglobin (there’s the connection between vampires and blood). Symptoms of porphyria include shrunken gums (that could make teeth look like long fangs), painful sensitivity to sunlight, and….and averse reaction to garlic. The reaction comes from the effect of garlic on the blood – it can stimulate red blood cell turn over and increase blood flow, both of which can exacerbate symptoms of porphyria and cause acute, painful attacks. There’s also an allegorical connection – vampirism was considered a disease (or represented the spread of disease in some literary cases) that was spread by a causal agent and garlic was seen as a curative for disease (it does have some antibacterial properties). Note: other possible symptoms of porphyria can be excessive hair growth in random areas of the body, which gives it a connection to lore around lycanthropy.

On to the gardening

Now that we’ve covered some trivial, albeit interesting, info lets get on with the gardening!

While many people are accustomed to the single variety available in grocery stores, there are several different types of garlic that all have different flavor characteristics. These types can be classed in two categories; hardneck garlic has a hardened central stem when it dries, and softneck garlics remain soft and pliable. Softneck varieties are the ones that lend themselves to being braided into those hanging garlic braids. Softneck varieties are also longer-storing than hardneck varieties.

It can be tough to find garlic in local garden centers to plant. Those that do carry garlic, often carry it at the wrong time of year for planting when it is shipped in on the spring garden displays. If you don’t have friends to share their garlic with you, or a local farmer to buy some from, you are going to have to go the mail order (or online order) route.

Once you have your garlic bulbs, split them up into cloves, being sure that you have a piece of the basal plate (the part that holds them all together) on the clove. This one clove will turn into a whole bulb over the growing season.

Plant the cloves tip up about 4 to 6 inches apart and about 2 inches deep in loose, organic soil. Mulch after planting with about one inch of straw or shredded newspaper.

Garlic is a relatively heavy feeder, so it would benefit from a good balanced fertilizer treatment with nitrogen after it is established. You can also plant them in the garden where you grew beans over the summer – the bacteria that colonized bean roots adds nitrogen to the soil.

After that, just be patient. It may pop up before winter if the weather is mild, but don’t worry – it can survive even if a freeze kills the growth back to the ground. Garlic requires little maintenance, and only requires water if the weather turns very dry. Harvest it once the leaves start to die in mid-summer (around July, unless it is an early-maturing variety). Be sure to save some to plant next year and store the rest for use in the kitchen.

Aside from garlic, there are some other odoriferous onion relatives you can plant this time of year like shallots and perennial onions in the vegetable garden or edible landscape.

Shallots have a mild onion flavor and are great because they form cloves like garlic (meaning you don’t have to cut up a whole bulb if you just need a little bit) and store well. The beauty of shallots is that they can also be planted in really early spring — they are a multi-seasonal crop. You can also start them from seeds in the spring.

Shallots are technically perennials, as they will grow over many years if left undisturbed. However, to harvest them, you have to dig them up so they are usually grown as annuals. Once you dig them up, use the larger bulbs for cooking and save the smaller ones for replanting.

Multiplier onions, sometimes called “potato onions” are another fall-planted perennial. These plants produce clusters of bulbs (hence the name “multiplier”) that are harvested in the early summer for bulb onions.

One of the benefits of these and other perennial onions is that you can harvest the green blades of the plant for use as green onions or scallions throughout most of the winter and spring.

Egyptian walking onions are another perennial that can be harvested either for its bulb or as a green onion. The name comes from the bulbils that form at the top of the flower stalk. When they mature, they get heavy enough for the stalk to collapse and fall over, creating a new bunch of onions away from the mother plant. You can allow them to do this to fill in an area, though most people limit it by harvesting the bulbils before they fall.

There are also perennial leeks that have a flavor similar to leeks and can be harvested as green leeks through the winter or dug up as small, tender leeks in the spring.

If you love growing perennial vegetables that add flavor to just about any dish, give these tasty plants a try. They’re really simple to grow and can keep your garden and your kitchen full of fun and flavors for years to come.

A quick primer on types of garlic

Hardneck Varieties

Purple Stripe — bulbs have purple on the outside. Some of the tastier garlics that become deliciously sweet when roasted.
Porcelain — popular gourmet variety. Usually has a more robust and spicy flavor. Bulbs are typically large and have large cloves.
Rocambole — Rich, complex flavors popular with chefs. Their scapes (edible blooms) form a double loop. They do not do well where winters are warm.
Asiatic/Turban — Do not store for long periods. Mature earlier in the season (late spring as opposed to summer) than other types. Flavors are usually strong and hot.
Creole — Attractive red color. Performs well where winters are warmer. The flavor is similar to (though milder than) Asiatic/Turban Varieties.

Softneck Varieties

Artichoke — the grocery store garlic (California White) is an artichoke garlic, though other varieties have more complex flavors. Bulbs tend to have multiple layers of cloves.
Silverskin — often the last in the season to mature, these are the longest-storing garlics.

Elephant Garlic

This is a common “garlic” planted by many gardeners because it has large, easy to use bulbs with a garlicky flavor. Though it is technically not a garlic species – it is a type of perennial leek.

Root washed perennials – 3 months later

You’ll recall that in July I posted about root-washing perennials before planting them in the middle of our typically hot and dry summer in the Pacific Northwest. I wanted to update everyone on how they performed now that we’re heading into our cooler and wetter fall months.

Just to remind you, here’s a photo of the garden right after planting:

And here is the same garden, 3 months later:

No plants died; in fact, as you can tell, they all thrived. They were watered twice a day during the hottest months and now are rain watered only. (The underlying soil is an excessively drained glacial till, which is why we water frequently during esablishment and why we don’t worry about the drainspout. Water doesn’t stay around long.)

I used no fertilizer. I did add the soilless media from the root washing to the top of the soil and then covered with woodchip mulch.

There was, of course, a period of about 6 weeks post planting where there was no above-ground growth. But all of these plants retained their flowers, which kept our bees and other pollinators (butterflies and hummingbirds) happy. In August, the plants started to put on new growth at a furious rate now that roots have established.

Take some time and go back to the original post (which is linked in the first sentence. Look at the roots – before and after washing and pruning. Now look at the results.

Why wouldn’t you plant this way?

My cucurbits won’t stop having sex.

Not really a botanically-correct statement, but you know what I mean. John Porter’s previous blog post did a great job of explaining cucurbit reproduction (loved the Pucchini). Though I was surprised to learn “not getting any fruit” is actually a problem. Can’t say I’ve had an issue with that, ever. We have a really vibrant bee population and they’ve been super busy.

I love growing squash of all sorts, despite not being a terribly gifted vegetable garder. Past Garden Professors posts have addressed this issue. One might ask, why on earth would a two-person household need a 60-foot-long row of zucchini? Because we can! Though if I recall, I intended to go back and thin the row. Whoops.

The zucchini hedge. And those aren’t weeds, they’re *biodiversity*.

By late summer, we usually end up with gummy stem blight, powder mildew or squash stem borer No sign yet, though any of these goodies could show up next week. The plants are all healthy and ridiculously enormous. It’s been very warm and dry, but we have a nice drip irrigation system in place.

So guess what happened when we got too busy to check on them for three days? Many more were still on the plants when I snapped this pic. I’ve worked zucchini in some form into every meal except breakfast. Joel’s still being a good sport. Next step is anonymous *gift* bags to folks at the office. Though I think I’m getting a reputation.

Normal-sized zucchini at top of photo for reference. Aargh.

Not all zucchini taste alike, as true fans know. The pale hybrid Bossa Nova, right, has very creamy and tender flesh with seeds that are really only noticeable when it gets, er, hefty. Bossa Nova is a recent All-America Selection and perfect for use with those spiralizer thingies. The ribbed/striped variety is Costata Romensco – an heirloom variety with really wonderful flavor. Humongous plants though, probably not the best choice for square foot gardening fans. Tigress is the white-flecked green selection, allegedly more disease resistant than most. Bright and sunny Gold Rush, an old-school AAS selection, adds some color and is a bit sturdier/keeps longer than yellow summer squash.

I won’t be trying to save seeds – as John noted, can be very tricky/futile when there are other cucurbits about. Plus it’s too much fun to pick out next year’s selections from the winter seed catalogs, when the prospect of bountiful zucchini stacked like firewood actually sounds appealing.

Sex and the Single Squash: A study in plant sex, sexuality, reproduction, and seed saving

In the 1960s, author and future Cosmopolitan magazine Editor Helen Gurley Brown scandalized the country with her book about independent single women called “Sex and the Single Girl.” Taking a page from Ms. Brown, we can have a discussion about “Sex and the Single Squash.” Here, we can talk about plant floral structure and reproduction and its effect on fruit production and even seed saving. A true discussion of the “birds and the bees” if you will. This is especially important in the vegetable and fruit realm, since reproduction is why we get tomatoes, peppers, apples, plums and such in the first place. It also is important for producing seeds, as those arise from the reproductive process as well.

Whether you knew it or not, flowers are not just different in appearance from plant to plant, but the ways in which they are pollinated and turn into fruit are different as well.

Some plants have what are called “perfect” flowers where both male and female parts are present, such as roses, apples and dandelions. In a way of speaking, you could say that these flowers are hermaphroditic. These flowers may or may not be self-pollinated. Depending on species genetics, some plants can self-fertilize (like tomatoes and beans) and others require cross-pollination (like apples).

Other flowers are “incomplete,” meaning that they have separate male and female flowers. Some plants with “incomplete” flowers are called dioecious (Greek, meaning “two households”), and have distinct male and female plants such as ginkgo trees, holly bushes and kiwi vines. Some “incomplete” plants are monoecious and have distinct but separate male and female flowers on one plant — like squash, cucumbers and corn.

So, here’s where the vegetable garden comes in — one of the questions that I get every year without fail has something to do with why most of the flowers on a squash or cucumber or other cucurbit (that’s what we call plants in this family) plant do not produce fruit.

There are a few explanations – high heat causing aborted flowers or fruits or improper pollination, absence of pollinators, or, most likely, the fact that some of those flowers were never going to set fruit because they were male. In answer, I have to explain that about half or more of the flowers on the plant are male and are, unfortunately, anatomically incapable of producing fruit.

There are a few ways to tell male and female flowers apart when it comes to members of the cucurbit family.

First, look at the base of the flower. If the base is swollen and looks like it is a tiny version of the mature fruit, then it is a female flower.

If the base is just a straight stem (in flowers, this stem is called a peduncle), then it is a male flower.

The second method is to look inside the flower. If there is one large central structure, called the pistil, that indicates the flower is female.

Male flowers will have several, smaller stamens inside. Female flowers also tend to be larger than male flowers.

In the world of the single, available female squash blossom, life revolves around attracting honey and other native bees that have also recently visited male flowers to assure pollen transfer.

All members of the cucurbit family require this pollination tango to make sure that the female flowers produce fruit.

Each species and even variety of squash have a different ratio of male to female flowers. The ratio is usually about 1-to-1, but it is not unusual to see varieties with many more males than females.

Many of the plants also produce an abundance of male flowers early in the season, sort of as a teaser to make sure bees are attracted to the plant later on to pollinate the female plants.

So if a majority of flowers die early in the season without setting fruit, or about half of the flowers die throughout the season, there is nothing to worry about.

If female flowers are dying throughout the season without producing fruit, though, there is a definite problem. This means that there are no bees available to pollinate the plants.

If fruits have shrunken parts or misshapen, then there could be an issue of incomplete pollination from not having bees around. This could result from not having enough food for them in the area to encourage their presence, or from weather being too cool or wet for bees to get out and pollinate.

The lack of bees could also be the result of improper use of pesticides in the area.

If it seems like the birds and the bees aren’t happening in your garden, there are ways that you can ensure fruitfulness by taking matters into your own hands.

Transferring pollen from male flowers to female flowers can be accomplished using a small artist’s paintbrush or by simply pulling off a male flower and using it to apply pollen directly.

Gardeners who want to save seeds from plants in this family should also pollinate flowers by hand, and actually go so far as to protect the female flower from outside pollen using some sort of cover.

In fact, this method is often used by plant breeders or those who want to save seeds of crops that easily cross-pollinate. Hand pollination followed by bagging the flower to keep pollen or pollinators away to avoid accidental unwanted pollen is often used to produce.

Believe it or not, several members of the squash family that look or taste nothing alike are the same species and can cross-pollinate. For example: Zucchini, summer squash, pumpkins, scallop squash, decorative gourds and acorn squash are all in the species Cucurbita pepo and can cross with each other.

A few years ago, one of my Master Gardeners came up to me at the end of a meeting and asked me what was wrong with her zucchini. She handed me an object roughly the shape of a zucchini, only a bit larger and splotched with orange. She had saved the seeds from the year before.

I immediately answered that her zucchini had crossed with a pumpkin. Both of these plants are the same species and can easily cross pollinate. Even if you don’t have pumpkins in your garden, bees can travel 2 miles or more in search of food. So she was left with what I would call a Puccini.

Easy cross-pollination of varieties is why the most common heirloom crop varieties you’ll find are tomatoes and beans. Both of these crops have closed flowers that help resist cross-pollination.

They are most likely to be self-fertile, meaning that the flower will pollinate itself without outside assistance. This helps the plant breed true — so next year you end up with something that’s roughly the same as what you had this year. These plants can be just a few feet away from a different variety and they will not cross pollinate.

If you want to save something that is bee-pollinated, like your squash, pumpkins or cucumbers, you might want to do the brush and bag technique. Otherwise you might end up with a surprise in the garden next year.

The heirloom varieties that we often save are open pollinated, meaning that when they cross with themselves their genetics are relatively stable and you won’t see a lot of difference from year to year. (There will still be some difference, so if you save seeds for a long time you can end up with your own strain of a variety suited to your garden and location.)

Hybrids, on the other hand, have less stable genetics than the open pollinated varieties. With the way genetics work, some of those offspring will have traits of the mother plant, some will favor the father and some will be similar to the plant you are trying to save (and some might look like the milkman).

When seed companies sell hybrid varieties, they have to maintain a population of the mother plant and father plant to cross them every year to get the specific hybrid variety.

While the results of saving seeds from hybrids will be unpredictable, it can also be fun. My friend, plant breeder Joseph Tychonievich, points out in his talks and his book, “Plant Breeding for the Home Gardener,” that you can save the seeds from plants most closely resembling the desired plant over several years.

Just keep planting your selected seeds and harvesting the closest one to what you want. After about three or four years, you can end up with a relatively stable, perhaps even open-pollinated variety, that is your very own based on that hybrid variety you love.

And if you end up with a cross-pollination, either purposeful or accidental, you won’t see a difference in the fruit from this growing season (except maybe in corn, but that’s another story) Those changes won’t be apparent until you grow out the seeds you saved. So you won’t know until next year if you have one of those pucchinis.

And don’t forget: If you do have an overabundance of male squash flowers, they are edible too. You can put them in a casserole, fry them, stuff them, and more.

Set your roots free on this Independence Day week!

We’ve discussed barerooting/rootwashing trees before, and research on this controversial topic continues. But what about smaller shrubs and woody perennials? What about herbaceous perennials? Basically, what about PERENNIALS???

I’ve always made a practice of rootwashing everything except for annuals. They don’t last long enough to suffer the perils of potbound plants. But many gardeners are nervous about disrupting more fragile root systems. Let’s see what happens when we do.

A little context: we’ve just moved to our family farm, which has AMAZING spring flowers that the bees love. But once those are gone…there’s nothing. I was desperate to provide some food for bees and butterflies, so it was off to the nursery to shell out a few hundred bucks for the beginnings of our south-facing pollinator garden – a previously barren spot left after construction of our porch.

So I bought Lavandula stoechas ‘Bandera Purple’ and ‘Winter Bee’, Salvia ‘Caradonna’, Agastache ‘Acapulco Deluxe Red’ and ‘Blue Boa’, Erysimum ‘Winter Passion’, Verbena ‘Homestead Purple’, and Lobelia laxiflora. I depotted and soaked them in a water bath, using a gentle hose setting to loosen up media in the center. For most of these plants, a massive root disk at the bottom of the pot had to be cut off like a giant slice of salami. If necessary, I “tickled” the remaining rootball to work out the rest of the media.

Here is Erysimum ‘Winter Passion’ potted, depotted, and washed.

The Agastache and Verbena cultivars were also in pretty good shape, much like the Erysimum. Just a gentle washing and tickling was enough to remove all the media and reveal the roots.

Here is Salvia ‘Caradonna’ potted, depotted, and washed, and Lobelia laxiflora potted, depotted, and washed.

Apart from the root Frisbee on the bottom of each pot, the roots were confined to the center of the pot, pretty much where they had been in their previous container. So question number one for all of you gardeners – why would you want to dig a hole to plant all of that media (which is nothing like your soil)? My answer – you don’t! Keep that good organic material as part of your topdressing.

Here is Lavandula stoechas ‘Bandera Purple’ potted, depotted, and washed;

and here is Lavandula stoechas ‘Winter Bee’ potted, depotted, and washed.

I have to take time out for a special rant about the lavenders (retailing at $19.99 and $12.99). Look at the root mass of the ‘Winter Bee’. It’s entirely unacceptable. The woody roots are in the shape of the liner pot from transplants past. News alert: these systems do NOT self-correct. They must be straightened or pruned to regain a natural structure. The ‘Bandera Purple’ – the more expensive of the two – was actually three plants in one color-coordinated bowl (“Go ‘Colour Crazy’ with matching pots and flowers”!). Fine by me – I just got 2 free plants. (By the way, this is nothing new for me – I’ve written about it previously here and here.)

Another upside is that hole digging was short and sweet. Holes were just deep enough to accommodate the root mass and wide enough to allow roots to be spread. Soil was added and watered in. The leftover organic media was used as the first layer of topdressing, followed by a fresh woodchip mulch. And then irrigation to soak the mulch well.

It’s important when you rootwash plants to provide optimal soil water every day, particularly when it’s hot and sunny (as this south-facing garden is). Even with the gentlest root washing there will be a loss of fine roots. But the continuity of the soil system means that the soil around the roots will be just as moist as the rest of the bed. Roots left in soilless media quickly dry out. Yes, I had afternoon wilt on many of the taller plants during the first week or so, but they recovered every evening. The wilt has become less noticeable since then.

So here’s how they look 3 weeks after planting (sunny day, about 80°F). And I’m happy to report that not only birds and butterflies but hummingbirds have been visiting our pollinator oasis garden. And all those single photos scattered through the post? They are all close-ups from this garden – taken just minutes ago.

(Question number two for gardeners – what are you waiting for?)

Bot-strosities

Those of you who are Stephen King fans will remember the Lobstrosities from the Dark Tower series: bizarre creatures that were part lobster and part scorpion and with the nastiest parts of each on either end.

Botstrosities are bizarre plants that aren’t deadly but still assault the senses of those who are unfortunate enough to find them. Here’s my collection – maybe you have others to add?

First up are a classic favorite – the GMOs (Glue Modified Organisms). Why bother with years of hybridizing when you’ve got a glue gun?

Everyone knows Cosmic Crisp apples. Now we’ve got Kosmik Kactus! Never mind they aren’t cacti. What I can’t wait for is these aloes to develop “glistening white” or “golden yellow” spines.

Definitely some alien species we could do without

Continuing the unfortunate trend of spraypainting plants, here are some for your favorite football fan (assuming their team is the Seahawks). Question: do other regions have spraypainted heaths in their team colors?

Now this *Calluna vulgaris* is truly vulgar

And do look forward to metallic jades for the winter holidays!

The perfect gift for the plant lover you hate

Spray painting too obvious for you? Well, how about surgically altered orchids? If you can’t figure out how the flowers developed this garish blue mottling just look closely at the stem.

They might as well be plastic – unnaturally colored and staked upright

We certainly wouldn’t sell spraypainted birds or kittens with bows glued on their heads. Just say no to these horticultural horrors!

The search for bogus info and products continues!

The Garden Professors, led by our warrior princess Dr. Linda Chalker-Scott, continue to ferret out bad advice, bogus information, and worthless products foisted upon the unsuspecting gardener.

I’m assisting in the hunt as well. See my survey link below. Looking specifically for :

1) Gardening-related blogs and vlogs (video blogs) that are out there – could be anywhere on the spectrum of misinformation: spewing pseudoscience or just plain malarkey. Or some of the content is o.k., but veers off occasionally into the land of the absurd.

2) PRODUCTS! I’m especially interested in this. There have been some hilariously useless things brought to our attention over the years, but new gardening products are constantly coming on the market to fill this or that perceived niche. The Amazonification of garden retail is exacerbating the problem. A brief example is a $94 compost “tumbler” that two heads of old cabbage would fill. Now roll around daily and wait… So let us know of any gardening product that you or a friend have purchased and it just didn’t work as promised (or failed in epic fashion).

Respond to Holly’s brief survey here!

All responses to my survey are confidential with no names used in the input or output, so feel free to include rants along with links. Will share what we gather in a future post (or two). Survey closes June 20, so don’t tarry. Thank you, and garden on!

Respond to Holly’s brief survey here!

Do your homework before hiring landscape help!

(A guest post by Rich Guggenheim. You can see Rich’s bio at the end of this post.)

When it comes to shopping, my friends all know it takes me a long time to make a decision. I methodically research out what I want. Then I narrow it down to a few items. After I look over my choices carefully, I may go home to get on the internet and look at consumer reviews; I may go from store to store and check out prices. I look for quality and I look to make sure I am getting a product that is worth the money I am spending on it. I want to make sure my investment will last. Sometimes, my shopping experience will last hours, days, or in the case of a car or computer, it could be months.

My yard is no different. When I need yard work done, such as lawn aeration or tree trimming, I am insistent on high quality work. As a homeowner you are the first and the last line of defense when it comes to making sure that a quality job is done, and done correctly! Knowing what to expect in landscape maintenance and being armed with a small amount of knowledge as a consumer can play in your favor.

Always hire a certified professional to do your work. Would you seek medical advice from an individual who was not licensed to practice medicine? Of course not! Why then would you do it with your yard? I recommend that you check into the individual or company before hiring them. Do some homework. How have they been trained? Where is their certification from? Are they insured, licensed, and can they provide you documentation? Are they registered with the Better Business Bureau? If so, what is their rating? Drive around and check on some of their previous work. Is it the kind of quality you would want in your own yard? Ask for references. Ask questions! This is, after all, a job interview for the contractor. Just because they are the cheapest does not mean they should get the job, and just because they slap a business magnet on the side of their pick-up truck does not mean they know what they are doing! In the following I will be talking with you about what to look for when hiring a contractor to do yard work and how certain procedures should be done. Armed with this knowledge, you will be better able to ensure the work done in your yard is of the quality you deserve for the money you pay.

Lawn aeration is perhaps one of the best things that you can do for your lawn. Done twice a year, once in the spring and once in the fall, core aeration combats soil compaction. Soil compaction is a problem in nearly 80% of all landscapes. In addition, aerating your lawn helps combat thatch accumulation and reduces the amount of water you need to apply to your lawn. The reason for this is because when your soil is compacted oxygen and water can’t penetrate into the soil. Fertilizer can’t get penetrate the soil either. As a result, roots are often shallow, and the lawn will need more frequent irrigation. (1, 2, 3, 4)

Core aeration removes small plugs, about 1-3 inches long from the soil. A single aeration using a machine with 1/2-inch diameter tines removes as much as 10 percent of the thatch if enough passes are made to achieve average 2-inch spacing between holes. Remember the key is 2-inch spacing. This may mean that multiple passes on the lawn are required. This small investment of an extra $10 will pay dividends in the end.

What do you do with the cores after you have had the lawn aerated? That really is a personal decision. Some people do not like the little plugs being left on their lawn, although there may be benefits to allowing them to disintegrate into the lawn again.

If you do decide to remove them, they are great for the compost bin. Other options may be to power rake the lawn after aeration, watering, or simply running a lawn mower over the lawn after you aerate (although this practice will cause the blades on your lawn mower to dull). Once you have aerated your lawn if you need to reseed, this is the optimum time to do it. The best part of reseeding now is there is no need to top dress the lawn, as the lawn seeds will have nice little holes in which to germinate!

Another type of aeration being marketed by many lawn care companies these days as a replacement for core aeration is liquid aeration. While different ingredients make up this popular lawn service, the main ingredients seem to be liquid humates (organic matter) and sodium lauryl sulfate (soap). These are nothing more than snake oil remedies and are no substitution for the real deal of removing the plugs from your lawn by core aerating. There is no scientific research which has shown chemical aeration to be effective. You may as well throw dirty dish water out on your lawn. (5)

The thing to remember from all of this is that you want to have your lawn aerated twice a year; in the spring, and again in the fall. The plugs removed should be 2-3 inches long, and on 2 inch centers, which may require multiple passes on your lawn.

Tree pruning is something I take seriously. It is a science which should not be left to a novice and is far more than could be covered in one article. For me, spotting a bad tree pruning job is as easy as spotting a bad haircut. The only difference is a bad hair cut grows back and has no adverse side effects on your health. However, a pruning job can have enormous effects on the health of a tree, either for good, or for bad. When you hire an arborist, make sure they are ISA certified, licensed, and insured. To find an ISA certified arborist, visit their website.

The key points for a good pruning job really come back to structurally pruning the tree correctly when the tree is young. Improper or lack of pruning when the tree is young can greatly increase the likelihood of tree failure when the tree is older. Cuts on branches larger than 4 inches increase the possibility of decay and disease. If possible, prune trees when the branches are smaller than 4 inches in diameter.

When pruning trees, it is important to prune the branch back to the branch collar. Don’t leave stubs, or what I call “hangars” where you can hang your coat. Leaving these nubs will cause decay and disease to move into your tree.

The last key component to pruning is to always remove a smaller branch back to the parent branch, never the other way around. When you remove a parent branch, unless the wood is dead, you greatly increase the risk of beginning the downward spiral of death and decay in the tree. While this is great for less reputable tree-trimming companies who will have to come back year after year to remove an ever-increasing amount of dead wood from the canopy of the tree, it is hard on your pocketbook; more importantly, your tree’s life is shortened! By knowing some pruning basics, you can ensure that you are hiring a professional who knows what they are doing, and will extend the value and life of your landscape.

Carrow, R. N., B. J. Johnson, and R. E. Bums. 1987. Thatch and quality of Tifway bermudagrass turf in relation to fertility and cultivation. Agronomy Journal, 79: 524-530.
Dunn, J. H., D. D. Minner, B. F. Fresenburh, S. S. Bughrara, and C. H. Hohnstrater. 1995. Influence of core aerification, topdressing, and nitrogen on mat, roots, and quality of “Meyer” zoysiagrass. Agronomy Journal, 87: 891-894.
Erusha, K. S., R. C. Shearman, and D. M. Bishop. 1989. Thatch prevention and control. Turfgrass Bulletin, 10(2): 10-11.
Murray, J.J., & Juska, F.V. (1977). Effect of management practices on thatch accumulation, turf quality, and leaf spot damage in common Kentucky bluegrass [Poa pratensis]. Agronomy Journal,(3), 365-369.
Lloyd M. Callahan, William L. Sanders, John M. Parham, Cynthia A. Harper, Lori D. Lester and Ellen R. McDonald.Cultural and chemical controls of thatch and their influence on rootzone nutrients in a bentgrass green.Crop Science, 1998 38: 1: 181-187. doi:10.2135/cropsci1998.0011183X003800010030x

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Rich Guggenheim is a consumer horticulture educator with the University of Idaho in Canyon County and is the program director for the University of Idaho Extension Master Gardener volunteer program. Rich is also working on a Ph.D. in plant pathology. Rich has been an horticulture extension agent for Colorado State University, horticulturalist for Disney Parks, and is the host of the weekly “Avant Gardener” radio program in Boise. He can be reached at richg@uidaho.edu

You, too, can be up to your pits in perennials!

(posted by Holly Scoggins)
The Perennial Plant Association (PPA) is a unique group of folks – comprised of plant breeders, educators, propagators, promoters, garden writers, growers, retailers, gardeners, and landscape designers – all under one umbrella. The PPA is probably one of the most vertically-integrated plant organizations out there. If it has anything to do with a perennial plant, there’s a good chance one of our members is involved.

The marvelous/legendary PPA Symposium has been held in all parts of the country. This year’s perennial-fest is in Raleigh NC. This goes back to my particular roots with the organization – my first PPA experience was in 1997 symposium, also in Raleigh, while I was grad student at NC State. Helped out in a few capacities, including tour bus wrangler (on the surprisingly rowdy bus, no less).

A special feature THIS year in Raleigh will be a one-day plant-geek-fest, open to the public as a separate registration item (of course any perennial freaks are absolutely welcome to attend the entire week of symposium events as well!).

Many/most of you are not located in the Mid-Atlantic/Southeastern region of the U.S. So why I am I touting this here? Because some of my biggest Ah-Ha! moments regarding growing and gardening have happened in places far from my comfort/hardiness zone. And the plants…oh the plants. In searching through my older GP posts, I’ve mentioned the PPA at least 9 times.

Recent examples: In 2016, the PPA symposium was in Minnesota… really opened my eyes, heart, and wallet to some lesser-known prairie species and design concepts. I probably have one of the larger Silphium collections in Southwest Virginia now. Whoops.

Last year’s symposium in Denver, Colorado brought with it awesome alpines and steppe plants – many of which I could grow here, with a bit of assistance from enhanced drainage. Of course there were also examples galore of rock gardening techniques to help make that “enhanced drainage” thing happen. Beyond the plants and gardens, another highlight is the opportunity to meet the area’s botanical movers and shakers that I wouldn’t have had otherwise. So much positive, fun energy – helps to remind me why I do this thing!

Joseph Tychonievich experiencing Perennial Overload Syndrome at the 2017 Perennial Plant Association Symposium last year in Denver. Triage included some deep breathing and a Sprite. Plant: *Dalea candida*. Place: Chatfield Farms, Denver Botanic Garden. Photo: H. Scoggins.

So…trust me when I say driving for 6-8-10 hours or hopping on a plane to the handy-dandy RDU airport will be WORTH IT. Especially if you stick around for core symposium including fab tours to private and public gardens, independent garden centers, behind-the-scenes at wholesale nurseries, and (wait for it) dinner and garden wandering/shopping opportunities at Plant Delights Nursery.

Back to the “Spend the Day with Perennial Plants” opportunity on Monday, July 30 – Check out this lineup for the plant talk day – and note the geographic diversity of the speakers – again, this isn’t just a “Southeast” thing!

– Patrick McMillan is an Emmy Award-winning host, co-creator, and writer of the popular nature program, Expeditions with Patrick McMillan . He’ll highlight Carolina native perennials for the garden in a morning talk. Later that afternoon, he’ll cover Southwestern plants we can use in the Southeast to cope with drought.

– George Coombs manages the horticultural research program at the Mt. Cuba Center in Hockessin, Delaware. This renowned botanical garden focuses on native plants, and their plant evaluations are making a big splash in the industry. Get a peek at the top-performing selections and find out what it takes to stand out in their trials.

– Christian Kress owns a specialty nursery in Austria that focuses on rare perennials from around the world. He’s traveled extensively, authored books, and introduced several beloved perennials to the market. He’ll bring the knowledge on flocks of Phlox (!) and introduce us to the amazing selections coming out of Russia.

– Judith Jones owns Fancy Frond Nursery in Gold Bar, Washington. She’ll open the world of ferns and inspire a new appreciation for their role in the landscape. [Am hopeful that frond puns will abound.]

Other presentations include iris breeder Kevin Vaughn; John Kartesz on native plant inventory software that generates customizable maps and databases; Larry Mellichamp on the world of unusual, surprising and bizarre plants; and Lauri Lawson on medicinal plants.

ALL THIS IN ONE DAY, PEOPLE.

The whole shebang takes place at the Hilton North Raleigh/Midtown. Advanced registration is required and early bird pricing ends June 1. See the program description and get registration information on the PPA Raleigh website. Be sure to check out the glorious e-Brochure just posted on the symposium home page. Hit me below with any questions – and would LOVE to see you there!