Good Growing Keeping you growing with good ideas Sun, 15 May 2005 13:02:08 -0500 https://web.extension.illinois.edu/hkmw/eb382/rss.xml A Few Spring Garden Tasks https://web.extension.illinois.edu/hkmw/eb382/entry_13844/ Wed, 20 Mar 2019 10:51:00 +0000 https://web.extension.illinois.edu/hkmw/eb382/entry_13844/ The weather is starting to warm up and the spring peepers are singing. There are going to be a lot of things to do out in the garden here soon. Here are just a few things to consider doing.

Don't be in too big of a hurry to clean up the garden. Many pollinators and other beneficial insects (predators, like ladybugs and syrphid flies as well as parasitoid wasps) are overwintering in plant debris such as hollow plant stems and fallen leaves. Ideally, you would wait to do any cleanup until temperatures are reliably in the 50s. If you can't wait that long, when cutting down old plant stalks carefully place them in piles out of the way so any insects that may be inside can still emerge and if possible leave some areas with fallen leaves undisturbed until it gets warm.

With all of the wet weather we've had recently don't be in a hurry to start working your soil, let it dry out first. Tilling or digging in wet soil will compact the soil and destroy the soil structure. Before working the soil take a handful and squeeze it. If it crumbles it's ready to work. If it forms a ball it's still too wet work with, so wait for a few days and test again.

Don't be in too big of a hurry to get things in the ground. If you do put plants in the ground, particularly plants that aren't very cold hardy, be prepared for late frosts. The median last frost date for this part of the state (central Illinois) is April 15 (that still means there's a chance there will still be a frost, the frost-free date is mid-May). Tender plants can be covered with row covers, blankets, or even a cardboard box. This will help trap some of the heat in the ground and help keep the plants from getting too cold.

When shopping for plants, make sure the plants you're buying are healthy, you don't want to be bringing problems into your garden. Plants should be green and healthy looking. Plants that have yellowing or browning leaves or stems should be avoided. Take a moment and check out the roots of the plants as well. The roots should be white and numerous. Also, look for any insect pests such as aphids, whiteflies, and scale. If you find any, avoid those plants.

If you are growing your own transplants, make sure you harden them off before putting them in the ground. Gradually introduce them to the outdoors over a seven to ten day period. By doing this your plants will get acclimated to their new environment and you'll have more success transplanting them.

Ornamental grasses and most perennials can also be divided in the spring (some fleshy rooted perennials such as poppy, peony, and iris are best divided in the late summer to very early fall). Ornamental grasses should be divided if the center of the plant had died out (looks like a doughnut) or they have gotten too big. Perennials can be lifted out of the ground and broken into sections (the bigger the section, the quicker they will reestablish). Discard any dead or diseased area of the plants.

These are just a few things that you can do to get your garden off to a good start this year.

Good Growing tip of the week: Cut back the foliage of ornamental grasses to about 4-6 inches in the spring before growth resumes. When foliage is removed, spring growth will begin earlier. Old foliage left on the plant can delay the crown's warming and subsequent growth by as much as 3 weeks.

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When is the Best Time of Year to Plant Trees? https://web.extension.illinois.edu/hkmw/eb382/entry_13833/ Mon, 11 Mar 2019 12:06:00 +0000 https://web.extension.illinois.edu/hkmw/eb382/entry_13833/ "Spring is better!" "No, fall is better!" "No, spring is better!" "Fall is better!"

What you are reading is the debate between two gardeners about when to plants trees. Here's the secret, they're both right and a little wrong, at least here in Illinois.

After a long, cold, and snow-laden winter, many of us gardener's are eyeing a particular spot. A spot that could use a tree. Fortunately for us gardeners, springtime heralds the newest stock of trees from nursery suppliers.

Most trees sold during the growing season are dug from the field while they are still dormant in the winter and then shipped to garden centers across the region. Even local nursery growers tend to harvest dormant trees from the field and then stage them in their holding areas where customers can select their ideal specimen.

You will find all manner of tree planting advice, but the debate of timing of planting is especially contested and can be confusing for most of us.

Essentially, the ideal time of year to plant a tree is when we receive regular rainfall. Based on that both spring and fall in the Midwest are good times to plant because these are times of the year when we tend to get more regular rainfall.

There are also some species that do better when planted in spring. On the flipside, some species are well-suited to fall planting.

According to the Morton Arboretum, trees that are slow to establish should be planted in the spring. These include bald cypress, American hornbeam, ginkgo, magnolias, hemlock, sweetgum, tuliptree, and willows.

Trees that can be planted in the fall include alder, Buckeye, catalpa, crabapple, hackberry, honey locust, Kentucky coffee tree, linden, maple, sycamore, pines, and spruces.

Regardless of when you plant, the survival of the tree depends on its care for those first two to three years in your yard.

The first watering after planting should be a deep soaking. It is also critical newly planted trees are well-watered going into their first summer or winter. Continue to provide supplemental watering at least once a week after planting. If Mother Nature yields one-inch of precipitation, then you can skip watering for that week. You will need to keep an eye on the water for up to three years, which is the time it can take for a tree to become fully established.

Mulch helps to insulate the root system and protect it from both winter and summer weather extremes. Use some type of organic-based mulch that will breakdown and add organic matter to the soil. Mulch two to four inches deep. Make the mulch ring as wide as possible. Avoid mounding mulch against the trunk. Mulch should never touch a tree!

Spring and fall planted trees should have their trunks wrapped in the fall to protect from deer rubbing and winter damage. A loose paper-based wrap works best. Remove wrapping as it begins to warm the following spring. In my area, we have to discourage nibbling deer. This requires complete physical exclusion. Our newly planted trees are in little tree jails. It is for their own protection!

One thing to keep in mind is if you do plant in the fall, it is likely that the tree has sat in the staging area all summer long and may be quite stressed. A benefit to fall planted trees is they tend to be on sale. I will admit to buying several trees on sale for fall planting. I learned the hard way; they were dead before I even put them in the ground. This makes buying from a knowledgeable garden center all that more important!

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Seed Starting https://web.extension.illinois.edu/hkmw/eb382/entry_13825/ Tue, 05 Mar 2019 08:42:00 +0000 https://web.extension.illinois.edu/hkmw/eb382/entry_13825/ As spring creeps closer and closer many of us are starting to get the itch to go outside and start digging in the dirt. While it's still too early to do that, it is time to start thinking about starting seeds indoors. If you've never started your own seeds before, there are several advantages to doing so.

When starting seeds indoors you tend to get better germination rates when compared to starting seeds outdoors because you are providing them with ideal conditions. In addition to better conditions, they also won't have competition from other plants and there should be fewer insect and disease problems.

Starting seeds to make your own transplants can also be cheaper than going out and buying them later in the year. You also have a lot more variety to choose from when you start your own seeds compared to buying transplants from the store (hundreds compared to a handful when it comes to popular plants like tomatoes).

Fortunately, starting seeds isn't very difficult to do. There are just a few things you need in order to get started: your desired seed, a container to start them in, some growing media, water, and light. When selecting a growing media use a seed starting mix, not garden soil. Garden soil is going to have weed seeds and possibly diseases in it. Additionally, garden soil tends to be very dense and heavy, which means it won't drain as well as seed starting or potting soil will. Seed starting mix is sterile and is usually made from milled peat moss, perlite, coconut coir, and vermiculite. This combination provides a light fine textured media that is ideal for starting seeds.

When it comes to your container, there are a variety of different options from plastic sheets of small containers (cell flats), plastic pots, peat pots, egg shells, toilet paper tubes, to egg cartons. Whatever you choose make sure it can hold your media while allowing excess moisture to drain away (i.e. drainage holes).

You have several different options when it comes to lighting too. Fluorescent grow lights are often used however, you can use regular fluorescent bulbs, a desk lamp or even a windowsill. If you decide to start your seeds on a windowsill make sure it has good southern exposure and it isn't drafty (you may need to provide some supplemental lighting though). For a more in-depth look at lighting check out Chris' post on supplemental lighting for seed starting.

Once you've selected the seeds you want to grow, take a look at the back of the package. It should tell you when the seeds should be sown or planted (generally x numbers of weeks before the last frost). It may also tell you how deep the seeds need to be planted.

Once you've gathered all of you supplies it's time to plant some seeds.

  1. Fill your desired container with your seed starting media, it's often easier to wet your media before filling the containers. Make sure media is settled and there aren't large air pockets in the container.
  2. Make an indentation in the media to the recommended depth. Place 2-3 seeds inside this indentation and cover with your media. Press the media down to make sure there is good contact with the seeds.
  3. Gently mist the media with water.
  4. The container can then be covered with plastic to help retain moister and warmth. Remove the plastic to spray container if the media dries out. If uncovered, the media will need to be watered more often. Once the seeds begin to germinate, remove the plastic cover.
  5. If you are starting seeds in a cool area it may be a good idea to get a heat mat, that is specifically made for starting seeds so that the seeds will properly germinate and to prevent disease problems.

As your seedlings grow, keep your lights 3 inches above the tallest plant and provide them with 12-16 hours of light a day (it may be a good idea to get the Christmas light timer back out so you don't have to worry about remembering to turn lights on and off). Water media as needed, making sure it remains moist. Once the seedlings produce their first true leaves, you can water with a weak fertilizer. Before you know it, it will be time to take them outdoors and place them in the ground, just make sure to harden them off beforehand.

Good Growing tip of the week: Start cool-season vegetables such as broccoli, Brussels sprouts, cabbage, and cauliflower around Late February and early March. Start warm season vegetables such as tomatoes and peppers around mid to late March.

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Cover Crops in the Home Garden https://web.extension.illinois.edu/hkmw/eb382/entry_13816/ Tue, 26 Feb 2019 17:00:00 +0000 https://web.extension.illinois.edu/hkmw/eb382/entry_13816/ Cover crops are turning into a popular topic in Illinois. Not only among farmers but also with gardeners. For the past four years, I have incorporated cover crops into my vegetable garden rotation.

Cover crops, also called green manures, are a great soil management tool for vegetable gardens and even home landscapes. Typically, cover crops do not have a harvestable portion but contribute to the garden in other ways.

Organic matter in the form of compost is the most common way a gardener helps to feed the soil and all those organisms living within. In most situations, compost can come with a higher price tag, so many are turning to cover crops to add organic matter and save a bit of money.

Cover crops can also act as a mulch to suppress weeds. Cereal rye is a popular cover crop that is sowed in the early fall and will put on significant growth the following spring. As the plant begins to form flowers it is flattened and crimped. Crimping is the act of breaking or pinching the tissue of the plant so that it can no longer function. There are lots of special tools that a home gardener can purchase to crimp a cover crop, but a simple piece of angle iron attached to a board will do the same job.

Cover crops can preserve soil and reduce erosion. Gardener's work so hard to build up our soils, let's not lose those gains by leaving soil bare and fallow during the off-season. I sow my cover crop in the late summer to early fall months right under the currently growing summer crops. By the time I'm ready to pull my tomatoes in the fall, there is a thick bed of oats and peas to protect the soil over the winter.

Another advantage of cover crops is they can be reservoirs for gathering important nutrients like nitrogen as well as micronutrients for the following year's vegetables. Nitrogen-fixing legumes like winter peas or sweet clover can take atmospheric nitrogen and store it in the soil.

Cover crops also can offer crucial habitat for insects and a food source for pollinators. Cover crops like buckwheat and clovers can be sources of pollen and nectar for beneficial insects. Note that buckwheat can reseed. Avoid the spread of buckwheat in your garden by terminating the crop with an herbicide, plow under, or plant in the early fall and let freezing temperatures do the job for you.

My favorite use of cover crops is one I've seen recently. The City of Macomb was planting oaks along a street in town. In order to remedy the compaction that is all too common in urban soils, the city used a cover crop of tillage radish. Tillage radish grows to near comical proportions, producing a huge taproot that can be up to two-foot deep and six inches wide. This helped to break up the horribly compacted urban soils and created a more habitable soil volume for the trees.

There are many different types of cover crops that can be planted at different times of the year. Spring and summer cover crops often need to be sprayed or plowed so they don't set seed. But sometimes cover crops like sweet clover can remain throughout the growing season to the benefit of pollinators. I prefer cover crops that are planted late in the growing season and will then winter kill. That way I don't have to worry about applying an herbicide or firing up the old tiller. The winter-killed plants lay down and create a mulch that prevents weeds in the spring. My fall cover crop mix usually includes peas, oats, and annual ryegrass.

There is a lot more cover crops provide to the soil and garden. Want to learn more about cover crops? Check out my podcast with Extension educator Duane Friend as we sit down and chat about cover crops for home gardeners. You can find the Good Growing podcast on the following platforms:

SoundCloud

iTunes

Stitcher

Google Play Music

Tunein

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Winter Tree Pruning https://web.extension.illinois.edu/hkmw/eb382/entry_13795/ Mon, 18 Feb 2019 11:45:00 +0000 https://web.extension.illinois.edu/hkmw/eb382/entry_13795/ Before we know it, spring will be here. Before getting too busy planting the garden, make sure to take some time to prune your trees (if they need it). While the old adage may say, "prune when your pruners are sharp", most deciduous trees are best pruned while they are in full dormancy. In this part of the country, February or March is a good time to prune. It is important that they are pruned while they are fully dormant. If pruned too early, and not fully dormant, they may produce new shoots that can be killed by cold temperatures. Another important reason to prune most deciduous trees during colder months, especially trees like oak and elms, is that pruning wounds can attract borers. These beetles can carry diseases such as oak wilt and Dutch elm disease.

Pruning in the winter also allows you to see the framework of the tree. This will make determining which branches and stems you want to remove easier. Start by pruning dead and dying parts of the plants first (this can be done at any point of the year, no need to wait for winter). After that, identify any problems you may see in the tree, such as crossed and/or rubbing branches (rubbing branches cause wounds that can allow diseases to enter), branches growing towards the center of the tree, branches with narrow crotch angles (these are more likely to break), multiple leaders, and branches that may pose hazards to people or property. By eliminating potential problems in younger established trees you can avoid extensive, and potentially expensive repair work to older mature trees. If you have large mature trees that need to be pruned, it may be best to contact a certified arborist. They will have the necessary tools and safety equipment to safely prune large trees.

Having the proper tools to prune trees is also important. Some of the tools you may want are hand shears for small branches up to ¼" in diameter and lopping shears for branches up to 1 ½" in diameter. Pruning saws should be used for branches over 1" in diameter and pole pruners can be used to reach branches beyond your reach. Also, make sure your pruners are sharp. If your tools are sharp it will be easier to make the cuts and the cuts will heal better (dull tools are more likely to crush or tear instead of cut).

For many years it was recommended that pruning wounds should be sealed (painted) to prevent pathogens from entering and to prevent the wood from decaying. However, this is not the case. Research has shown that it is not as helpful as once believed. Often times the coating will crack, allowing moisture to get in and accumulate. This is an ideal environment for wood-rotting organisms. Trees will naturally heal the wound themselves (callusing) and sealing the wound actually slows this process down.

Good Growing Tip of the Week: If you're in need of a certified arborist, the International Society of Arboriculture has an online directory of certified arborists. It can be found at treesaregood.org.

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Beyond Impatiens Downy Mildew: What’s next for America’s favorite bedding plant? https://web.extension.illinois.edu/hkmw/eb382/entry_13788/ Tue, 12 Feb 2019 16:45:00 +0000 https://web.extension.illinois.edu/hkmw/eb382/entry_13788/ Impatiens (Impatiens walleriana) is one plant I had written off years ago. In my mind, I thought I had seen the last of one of the most popular bedding plants in the nursery trade. Impatiens were fast disappearing from garden centers because of an incredibly infectious disease – impatiens downy mildew.

Impatiens is a powerhouse annual and was the go-to bedding plant for those gardening in the shade. In fact even today, it is still readily available in many garden centers. So why the doom and gloom on America's favorite bedding plant?

I first wrote about impatiens downy mildew in 2013 as it had been appearing sporadically throughout the Midwest for several years and had been confirmed in most of the Eastern US including Texas and Oregon. The disease is fatal to infected impatiens and the pathogen remains in the soil.

Impatiens downy mildew may be a disease you've never seen before, or like me, be all too familiar with when it popped up in my garden. If this disease is news to you, here are some tips for spotting downy mildew on your impatiens.

Officially known to plant pathologists as Plasmopara obducens, Impatiens Downy Mildew is a fungus-like pathogen that causes symptoms starting with yellowish or pale-green foliage, progressing to downward curled leaves, leaf distortion, and white to light-gray fuzz on leaf undersides. As the plant battles this disease it replaces infected leaves with new ones, however, these new leaves are small and discolored. The flower buds fail and defoliation can occur. In other words, this disease will leave behind bare stems and no blooms. The perfect environment for impatiens downy mildew is rainy days coupled with cool night temperatures. But once infected, researchers have seen this disease progress in hot, dry weather.

Many garden centers pulled this popular plant from their shelves or spray it with a rigorous schedule of fungicides to keep the disease at bay. But who wants to spend money on plants doomed to die? Other shade-tolerant species have now taken the place of impatiens, like the New Guinea impatiens that are resistant to the disease. There is an unseen benefit here somewhere. Yay plant diversity!

Now after more than five years, there is a ray of hope for us shade-bound, impatiens lovers. Two companies, Syngenta and PanAmerican Seeds will be launching the first impatiens with downy mildew resistance to the US market. Syngenta will release their new line of impatiens called Imara XDR this year, 2019. The XDR stands for "extra disease resistance". To get the XDR title, breeders have to get their claims verified by independent third-party experts, So Syngenta turned to plant pathologists at Cornell, who confirmed the claims.

PanAmerican Seeds will be releasing their new "highly resistant" line of Beacon Impatiens to select nurseries in 2019, with a full US market launch in 2020.

So what does this mean for us shade gardeners? We might be able to plant impatiens without fear of them all dying! If you are picky about blooms, both Imara XDR and Beacon Impatiens will be available in a wide range of colors. Nevertheless, now the challenge will be finding a spot for impatiens among my new staple shade annuals of begonia, caladium, and coleus.

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Insects and the Cold https://web.extension.illinois.edu/hkmw/eb382/entry_13782/ Tue, 05 Feb 2019 15:51:00 +0000 https://web.extension.illinois.edu/hkmw/eb382/entry_13782/ With the recent cold snap/polar vortex many people have also been wondering about how it's going to affect the insect populations. I hate to be the bearer of bad news, or perhaps good news (depending on your thoughts on insects) but, for the most part, most insects will survive just fine. Insects use a variety of strategies to survive through the winter.

The first strategy some insects will use is to avoid the cold altogether. Some insects that we find in Illinois won't survive our freezing winter temperatures. So, instead of trying to make it through the winter here, they'll survive elsewhere. An example of this would be monarch butterflies. As we approach fall, monarchs will begin to migrate south and will eventually reach Mexico where they will overwinter. As temperatures begin to warm again come spring, they will begin migrating north and their children or grandchildren will arrive in Illinois. Others, like armyworms and potato leafhoppers, survive in Southern states and will migrate north as temperatures begin to warm.

For those insects that stick around, low temperatures aren't necessarily the problem; the formation of ice crystals in their bodies is what makes survival difficult. If ice crystals rapidly form in their bodies, their cells will burst, resulting in damage and likely death. Some insects, like woolly bear caterpillars, will avoid this by using chemicals to control the way in which and where they freeze and therefore minimize damage to their cells (these insects are called freeze tolerant).

The other strategy insects that stick around for the winter use to survive is to produce chemicals in their bodies to avoid freezing altogether (these insects are called freeze intolerant). As temperatures begin to cool, these insects will start creating anti-freeze chemicals. These chemicals allow the insects bodies' to supercool (reach temperatures below freezing, 32ᵒF). Therefore the insects won't freeze until they reach their supercooling point. Some insects that take this approach include Japanese beetles (supercooling point is 19ᵒF), emerald ash borer (supercooling point is -13ᵒF), and codling moth (supercooling point is -10ᵒF).

Just because temperatures don't hit the supercooling point of an insect it doesn't mean some won't be killed. Perhaps the insect people are most excited about being 'wiped out' by the cold is emerald ash borer. A study by the U.S. Forest Service showed that 5% of the insects die at 0ᵒF, 34% at -10ᵒF, 79% at -20ᵒF and 98% at -30ᵒF. That being said it's important to note that emerald ash borer doesn't overwinter in exposed areas.

While air temperatures in many places in Illinois got colder than the above supercooling points, most insects will overwinter in protected areas where temperatures did not get nearly as cold. For example, white grubs (like Japanese beetles) in the soil will not be exposed to extremely cold temperatures because the soil will insulate them. Others will seek shelter under leaf litter (codling moth), under bark (emerald ash borer), or even in your home. All of these will provide some protection from cold temperatures. Snow is also an excellent insulator, and all of our snow offered another layer of protection. While the brutally cold temperatures may have seemed like they lasted forever, in reality, they only lasted a relatively short time and likely didn't drop temperatures in these protected areas low enough to 'wipe out' these pest insects.

While the cold temperatures we've had have likely killed some insects, come spring it should be business as usual.]]>