Ward Upham: Extension Blog Contributor Extension Associate – Home Horticulture Rapid Response Coordinator
& Extension Master Gardener Coordinator
Kansas State University Extension
Apple trees that are not pruned for several years will often produce so many branches that very little energy is left for fruit production. Overgrown apple trees are also difficult to harvest and spray. Gardeners who have such a tree are often at a loss as to how to get it back in shape.
Often the best (tongue-in-cheek) recommendation s for such a tree is to make one pruning cut at ground level and start over with a new tree. However, trees may have sentimental value that will make revitalization worth the time and effort. Realize that this will be a multi-year process because no more than 30 percent of the tree should be removed in one year. Here are some steps to follow:
Remove all dead wood. This does not count toward the 30 percent.
Remove suckers from the base of the tree.
Choose approximately six of the best branches to keep as scaffold branches. Remove all others. Branches should be cut flush to the branch collar. The collar is that natural swelling that occurs where a branch connects to the trunk or to a larger branch. Removing the collar would leave a larger wound that would take additional time to heal. Do not paint wounds. Research has shown that wounds heal more quickly if left open. Candidates for removal include branches with narrow crotch angles, which are more likely to break in wind and ice storms, and those that cross branches you will save. This may be all that is possible the first year if the 30 percent threshold has been reached.
Thin the branches on each scaffold branch. Remove crowded branches to open up the tree to light and allow humidity to escape. Shorten each scaffold branch by cutting back to a side branch. When you are through, the tree should have enough wood removed so that a softball can be thrown through the tree.
Severe pruning often will cause an apple to tree to produce vigorous side shoots from the trunk, called water sprouts. Main branches will also produce suckers that grow straight up. The suckers and water sprouts should be removed throughout the growing season so the center of the tree stays open.
In the case where a tree cannot be saved but you would like to preserve the apple tree variety, consider grafting. Scions taken from the old tree can be grafted onto a new rootstock to form a new tree. If you are not able to do so yourself, contact a local fruit tree nursery to find someone who may be able to help.
William H. McCaleb, Blog Contributor
Program Assistant for Agriculture and Natural Resources, Halifax County, VA. and Master Gardener
For gardeners in the eastern U.S., last year was a better than normal gardening season. Better than normal yield, better than normal precipitation, and in our case in Virginia cooler than normal which yielded excellent spring cool season crops as well as early summer crops.
But all good things must come to an end; that being the result of several heavy frosts. With that said, I am looking forward to next year’s challenges and what I want to grow for our family. Oh, for the taste of one more summer ripened tomato, but for now, that is a dream and it is time to reflect on what grew well in the garden as well as what didn’t do so well. Hopefully you have kept a garden journal to help you in this task. I find that writing down details of what is planted, the orientation, spacing, fertilization/liming rates and frequency, weekly rainfall amounts, production amounts, etc. is helpful as you start planning for the next season.
Like me, you should start thinking about what you want to grow in 2015. Take time to reflect on your 2014 garden production, care, and location. Also, evaluate what went right and what went wrong with the plants and varieties you planted and harvested. This will start you off in the right frame of mind in preparing for the next growing season. Good planning and preparation for next year gives you the tools to have an even better gardening season. A successful vegetable gardener is a happy well fed gardener!
I know, you too are already missing those fresh tomatoes, potatoes, peppers, squash, okra, and other great home grown vegetables we treated ourselves to this year, but the next season is ‘just around the corner’ so to speak. After all the days are getting a little longer. Spring can’t be far away!
If you just happen to live in an area that hasn’t had frost yet, take your prompt from your plants: when annuals and seasonal vegetables turn brown and begin to die back, it is time to clean up your garden.
Clean up the Garden Your best action is to remove any spent or failing plant materials. Experienced gardeners know that many of the bacteria, fungi, and other disease-causing organisms that caused those diseases. Pathogens that are sources of those diseased plants this past season can survive over the winter in dead leaves, stems, roots, and dropped fruits that get left in the garden. Much like a piece of bread that is kept too long and looks like it has penicillin growing on it, garden debris also will carry the pathogens that can come alive with those same problems when the temperatures begin to rise in the spring. Prevention of diseases and insect infestation now, will keep you from a repeat of problems in next year’s garden.
A good leaf rake, given enough ‘elbow grease’, works well in getting the bulk of dead plant material out of your garden. If you experienced early or late blight or other tomato related diseases this past growing season, you want to make sure you reduce, to the best of your ability, the risk of repeating that problem again next year. Yes, there are many new varieties of vegetables available today that are ‘resistant’ to some of these diseases, but ‘resistant’ does not mean they are immune to them. You don’t want to take the chance of returning pathogens, so do a good job, cleaning and ‘sanitizing’ your garden now. Make sure, when removing the plant debris, that you totally destroy that debris so that no pathogens are left behind.
To Compost or Not! Can you compost this dead plant material and use it next spring? Information that you find from Extension offices across the U.S. will recommend that you do not. The reason being is that most people do passive composting i.e. put it in a pile, and then using what compost develops, put the compost back in the garden for the next season. It is best to burn the plant material; this will destroy the pathogens and weed seeds as well and return some carbon back into the ground when you spread it out. Please check local/state laws prior to burning. Many states and/or localities have burn bans especially this time of the year. Another method, if your local law allows it you can bag the material and send it to the landfill. Each year there are more localities that ban yard waste from their landfills. If you are not sure, check with your locality to learn more about your local waste and recycling laws.
If you do decide to go with active composting; composting at a temperature 140°F, or higher, will destroy many of the disease organisms as well as many weed seeds. You will need a temperature probe to monitor compost temperatures. It’s really not hard to source a compost thermometer either through the internet or local retail outlets such as garden centers or nursery supply stores. If in doubt about your compost pile reaching these high temperatures, it is best to side with caution and discard the material by properly bagging it or by burning based on your local ordinances.
Preventing Overwintering Pathogens Some of our most notorious insects of the garden such as Mexican bean beetle, squash vine borers, European corn borer, cabbage loopers, can also overwinter in garden debris. Larvae will use debris as a safe harbor. Flea beetles and spider mites, as well, can find food and winter shelter in spent plant material and weeds.
After you have finished cleaning up the debris from your garden, it is time to turn over the soil to both aerate and break up any remaining debris into smaller pieces that will be turned under. A good rototiller will help make this job easier. Once buried, any plant material left will decompose more rapidly.
For some pests and pathogens, turning over the soil after removing spent plant materials is recommended as the main line of defense against overpopulation next year. Consider this information from “Home and Horticultural Pests: Squash Bugs and Squash Vine Borers,” from Kansas State University,
“A vigorous autumn… rototilling can physically destroy cocoons and larvae (of the squash vine borer). Brought to the surface, cocoons and larvae are more susceptible to predation by birds and exposed to cold winter elements, leading to their demise. Deep plowing physically destroys cocoons and larvae burying them deep beneath the soil surface so pupated moths become entombed underground.”
Steps to a Healthier Garden If you haven’t done a soil test in three years or more, it is time to retest and determine the needs of your garden soils based on what you will be growing in the next season. Soil test kits and instructions are available from your local Extension Office. Also, in planning next year’s garden, rotation of your crops is a must do item. This simple action will help keep disease issues down. If your soil test(s) recommend liming, you can go ahead and put down lime this time of year, allowing it to start adjusting the pH. If the ground is frozen already, wait until spring. As you add lime, you can also help build soil structure by incorporating compost or shredded leaves. These soil additives will also add beneficial micro-nutrients and beneficial organisms. If you want to further build the soil, you may want to consider putting in a cover crop that will not only hold soil, but when tilled in early spring, will further build a healthier garden soil. A legume such as white or red clover would be something to consider. Check with your local Extension Office for best cover crop recommendations for your area.
Briefly, chile seeds (Capsicum annuum) were placed into petri dishes, covered to ensure darkness, and then the dishes were placed in a circle. In the middle of the circle was either an empty acrylic box covered in black plastic (the control), an acrylic box covered in black plastic containing an adult basil plant (Ocimum basilicum) called the masked treatment, or an adult basil plant without a box (the open treatment). Seeds were watered and inspected daily for germination and the petri dishes were randomly rearranged.
According to the authors, “the presence of basil positively enhanced germination rates of chilli seeds, validating the claims of many gardeners who recognise the beneficial effect of basil on the growth of chilli plants.” Their reasoning is that the open and masked treatments induced more seed germination than the control. And since there was little difference between the masked and open treatments, they claim that the phenomenon is due to some signal other than light or gas (since the black plastic-covered acrylic container would prevent this).
How does this work? Well, according to the authors, this is evidence that acoustic signals are “generated in plants by biochemical processes within the cell, where nanomechanical oscillations of various components in the cytoskeleton can produce a spectrum of vibrations.” Never mind that the experimental design and methodology was laden with opportunities for experimental error. In particular, opening the petri dishes to water and count germinated seeds every day is deeply flawed. The easiest and least error-prone method would be to have the petri dishes sealed with parafilm to prevent water loss and inspected ONLY after the experiment was over. That is the standard method for testing for germination rates. Moreover, opening the dishes to count and water seeds every day really screws up the “covered to ensure darkness” part. In fact, chile seeds germinate better with light – which is what they got every day when they were opened. Was each dish exposed to light for exactly the same time every day? Exposure to light converts the seeds’ phytochrome to what’s called the active form, and phytochrome plays a crucial role in seed germination. The longer the light exposure, the more phytochrome is converted.
Now, plant scientists would know these things when they were designing their experiments. But as neither of the authors have degrees in plant sciences, it’s understandable. What’s not understandable is how this article got through peer-review. Unless none of the reviewers were plant scientists, either.
For those of you that belong to a university journal club or some other science discussion group, I think this would be a great article to discuss.
Sweet potatoes (Ipomoea batatas) are warm-season plants in the morning glory family (Convulvulaceae). The part we eat is the fleshy storage root of the plant, which is a little different than the regular Irish, or white, potato (Solanum tuberosum), a plant in the family Solanaceae. In that case, the part we eat is a fleshy underground stem of the plant, called a tuber.
Although sweet potato roots continue to grow until frost kills the vines, an extremely hard frost can cause damage to the ones near the surface. Chilling injury also results when soil temperatures drop to 50°F or lower, and this can result in internal decay in storage. The greatest danger from delayed digging is the risk of cold, wet soil encouraging decay. So the best time to dig is around the time of first frost in your area, or shortly thereafter. The vines can be clipped approximately 5 days before digging to improve skin-set or reduce the incidence of skinning the roots during harvest. To avoid exceptionally large sweet potatoes, a few hills should be dug in advance of the anticipated harvest date to determine the size of the sweet potato roots.
Freshly dug sweet potato ‘Puerto Rico’
You can cook newly dug sweet potatoes right away, but their flavor, color and storage quality is greatly improved by curing at warm temperatures immediately after harvest. It is during the curing process that starch is converted to sugar.
Cure sweet potatoes by holding them for about 10 days at 80-85°F and high relative humidity (85-90 percent). Commercial producers have temperature and humidity controlled housing to guarantee good results, but for the home grower, they can be cured near a furnace or heat source to provide the necessary warmth. If the temperature near your furnace is between 65-75°F, the curing period should last 2-3 weeks. To maintain the required high humidity (85-90 percent relative humidity), stack storage crates or boxes and cover them with paper or heavy cloth.
Sweet potatoes curing
Once the sweet potatoes are cured, move them to a dark location where a temperature of about 55-60°F can be maintained, like an unheated basement, or root cellar. Sweet potatoes are subject to chilling injury, so don’t refrigerate them. Outdoor pits are not recommended for storage because the dampness encourages decay. Good results can be obtained by wrapping cured sweet potatoes in newspaper and storing them in a cool closet. Sweet potatoes can also be stored in sand.
Ornamental Sweet Potatoes
Have you ever wondered what, if any, is the difference between the ornamental sweet potato vines grown as a season-long ground cover, or, as “spillers” in container arrangements, and the vegetable we grow as food? The answer is – not much. They are just different cultivars of the same plant species, Ipomoea batatas. The ones we grow for food are selected and bred to produce large, uniform, good tasting roots, high in nutrients for eating, whereas the ones we grow ornamentally are selected for the striking shapes and colors of their leaves. Plant breeders introduce new variations every year. If you dig up the earth around your ornamental vines, you’ll find the same fleshy roots (different colors, perhaps) as the familiar ones we grow, or buy, for food. So, can you eat them? Well, technically, yes – but there’s no guarantee how they’ll taste. Most ornamental varieties are pretty bland. However, if you dig, cure, and store them as above, it’s possible they can stay viable until spring, when you can try to continue their growth for another season.
Propagating new plants (called slips) the following spring
Infographics can be great: They’re bright colorful ways to make sometimes complex concepts visual and easy to understand. Sadly, “easy to understand” does not necessarily equal “accurate” and they can also be extremely misleading.
Take this beautifully made image from National Geographic. It is an older image — first posted back in 2011, but it makes the rounds on social media from time to time, and popped up in my facebook newsfeed a couple days ago.
Look at it! Oh no! We’re loosing all of our vegetable genetic diversity!
Or not. First, it is comparing apples to oranges. This image looks a commercially available varieties in 1903 and compares it to the number of varieties in one specific center for preserving genetic diversity. What happens if we compare the same metric? If you look at the number of varieties in the National Seed Storage Laboratory, that was founded in 1958… so in 1903, at the top of the graph, the number for all these vegetables would be… zero. If you look at the present day, the current umbrella organization for all the US government funded efforts to preserve genetic diversity of crop plants is GRIN, (Germplasm Resources Information Network) and if I do a quick search through that database using the keyword “tomato” I get… 9281 results. That is a pretty overwhelming improvement over 79 in 1983.
And what about commercially available varieties? To use tomato as an example again, in 1903, they found 408 varieties offered commercially. I just added up the varieties listed by just ONE seed company, Baker Creek Seeds, currently lists 287 different varieties of tomatoes. That is just ONE company. I have no doubt that if I added up all the varieties that are offered for sale in the giant pile of seed catalogs I get every spring it would be FAR more than the 408 on offer in 1903.
So… are we losing genetic diversity in our crop plants? Probably. There are lots of traditional varieties and land races that were never available commercially that have do doubt been lost, but to be honest, I think we’ve done a pretty good job at preserving the diversity. And certainly the USDA’s system of gene banks is an incredibly well run, impressive thing that deserves high praise indeed, for not merely preserving vast amounts of important genetic diversity but also working hard to characterize it and make it available to researchers and breeders so it can actually be put to work in the development of new and improved selections to try and feed the world.
So despite how colorful and easy to understand this infographic is, you don’t need to freak out about a massive loss of genetic diversity in our vegetable crops. Save that freaking out for all the wild species that have gone extinct or are about to go extinct thanks to habitat destruction and climate change world wide…
I don’t grow vegetables at home, mostly because I don’t have the space and partially because I don’t have the time. But I did want to try the potatoes-in-a-barrel method, which I also tried last year. But this year I planted about 6 weeks earlier (end of April) than I did the previous year (mid-June). Here’s my mid-October harvests from both years:
Next year I’ll try planting even earlier. It’s not a huge harvest, but it’s fun to do, especially with kids. A richer media (like a green compost along with soil) might give you a better harvest.
If you want to try this yourself, here’s how to do it:
1) Use a plastic trash bin with holes drilled into the sides. Be sure to locate the barrel in full sun.
2) Put a layer of soil on the bottom, and add potatoes. (You can cut them into smaller portions, each with an eye, if you don’t have as many sprouted ones as I did.)
3) Cover with soil and water well.
4) As shoots and leaves emerge, continue to add soil or other media to the barrel, leaving the tops of the shoots and a few leaves exposed. I used a mixture of soil and composted wood chips. Water well.
5) Continue to add media as needed, and continue to water through the season.
6) When leaves begin to die back, you can dump the barrel onto a tarp and pick out your potatoes. Save the media for next year’s barrel.
One of the things that comes along with having an extension appointment at a major university is I get lots of calls and e-mails from homeowners on a never-ending list of sometimes bizarre tree topics. Technically, my extension responsibilities are related dealing with professionals; such as arborists and nursery and Christmas tree growers, but the ‘consumer horticulture’ calls still find me. Last week I received a voice-mail message from an excited gentleman speaking at a decibel level somewhere between rock concert and jet plane take-off. From the disjointed and rambling message I could tell the gentleman was elderly and maybe disoriented or had just had a few. After identifying himself he indicated that he wanted to learn where he could find a “pine-nut tree”. Although he didn’t give it, I knew the man’s location from his area code. A legitimate response to such calls is to redirect them to the individual’s local extension office, but I hate getting the runaround as much as the next person, so I usually respond when it’s something I can help with and in this case I could.
I dialed the number and the gentleman picked up right away. He sounded just as he did in the voice mail; gregarious, slightly rambling, and VERY LOUD. His story, however, made me glad I called back. His father had emigrated from Lebanon many years ago and he remembered how his dad had always reminisced about eating pine nuts in the Old Country. For years he had wanted to plant a “pine nut tree” in memory of his dad. The problem was every time he went to a nursery and asked for a “pine nut tree”, nobody knew what he was talking about.
Pine nuts. Photo: Paul Goyette – Wikimedia commons
Pinus pinea cone. Photo: Luis Fernandez Garcia – Wikimedia commons
I explained to him that the pine nuts his father cherished were from stone pine (Pinus pinea) trees, which are the pine nuts (pignoles) favored for making pesto. In the US, the pine nuts that are sold commercially usually come from pinyon pine (Pinus edulis), which is native the southwestern US. Unfortunately, neither of those trees will grow in the Upper Midwest, where he lives. I pointed out that there are many other pine trees that produce edible nuts – the main reason those two species are widely used is because they produce very large nuts making them relatively easy to harvest. In fact, there are about 20 species of pine that produce seeds large enough that harvesting the nuts is worthwhile. Two pine species that produce edible nuts and grow well in our area are Korean pine (Pinus koraiensis) and Swiss stone pine (Pinus cembra). I include both in my recommendations for alternative conifers for Michigan. I gave the gentleman some information on nurseries in his area that I knew carried those trees and he was excited to have some direction on his quest to renew his father’s memory.
Korean pine (Pinus koraiensis) at the University of Minnesota Landscape Arboretum
Swiss stone pine (Pinus cembra) at Hidden Lake Gardens in southeaster Michigan.
Sidenote: The heartbreak of ‘Pine mouth’.
Have you ever experienced a bitter or metallic taste that persisted for days, even weeks, after eating pine nuts? Then you’ve likely experienced Pine Nut Syndrome or ‘Pine mouth’. The cause of the disorder is not completely known, but research by an industrious graduate student in the Netherlands suggests that nuts from certain pines; particularly an Asian pine, Pinus armandii, are most likely to cause the issue. So, if you are a pine nut fancier, learn what you can about your source. Pine nuts supplies can be cyclical since pine nut crops are often subject to biennial bearing. Soaring prices during poor supply years provide incentive for inferior nuts to work their way into the market.