Good Growing Keeping you growing with good ideas Sun, 15 May 2005 13:02:08 -0500 Beyond Impatiens Downy Mildew: What’s next for America’s favorite bedding plant? Tue, 12 Feb 2019 16:45:00 +0000 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.

Insects and the Cold Tue, 05 Feb 2019 15:51:00 +0000 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.]]>
Extreme Cold and Your Plants Tue, 29 Jan 2019 09:33:00 +0000 Being a fan of winter, this weather has been an absolute blast, but even I must admit- darn it's cold out there. One question I have been hearing a lot is "What about our plants?" Well, if you religiously adhere to the USDA cold hardiness zones then you should have nothing to fear. More than likely your trees, shrubs and perennials will emerge and leaf out to greet the spring. But who are we kidding? Gardeners are notorious for pushing the envelope when it comes to growing plants that are not necessarily suited to our local climate. As I sit here in USDA hardiness zone 5, I wonder, did my zone 6 magnolia and crape myrtles make it? What about the garlic I planted in my containers? Only time will tell.

My oldest son recently asked me, "Why don't the trees die in the winter?" I am likely the best or worst person to answer this question, depending on your perspective.

While this may have been uttered from the mouth of a child, scientists have been thinking about trees and winter for a long time. After all, the Earth used to be much warmer with a predominately tropical climate. So how did plants acquire the ability to survive the big cool down?

One of the biggest stresses a plant faces in a frigid winter is drought. Yes, drought! The majority of tree roots occupy the top four to eighteen inches of soil, and if the soil is frozen to that depth, the water is locked in the ice and not available to plants. Oddly enough, the droughts experienced by plants in our prehistoric world favored the evolution of plants that are better adapted to winter conditions. Over those millions of years, deciduous and evergreen plants have, developed creative survival strategies. For instance, the rugged and evergreen rhododendron leaf has developed a waxy coating that protects from freezing temperatures and reduces water lost to evaporation. Needled evergreens have minimized their leaf surface area curtailing water loss during sunny and windy winter days.

Narrower xylem tissue (the plumbing in the plant that transports water from roots to shoots), developed in response to prehistoric droughts. These narrow xylem tubes are also is very useful for trees to reduce the size of air bubbles formed when water freezes in their vascular tissue.

Moreover, trees learned to deploy one of the most effective tools, sugar. Sugar acts as a form of anti-freeze in plant tissues. As winter approaches evergreens use sugars in their leaves to prevent water in their cells from freezing. Deciduous trees also employ this technique. Remember those red fall colors? That's partly due to the sugars in the plant protecting the leaf long enough for the tree to resorb its energy.

We have been fairly lucky that with each severe cold snap we had an insulating layer of snow. Hooray! Snow is good! For the most part, I am not worried about my zone 6 plants, having sited them in areas with southwest exposure, blocked from desiccating winds and the advantage of radiant heat from adjacent hardscapes and buildings. For my perennials and garlic, I made sure to apply shredded leaf mulch as an insulating barrier to the cold temperatures.

Composting with Worms Tue, 22 Jan 2019 15:12:00 +0000 Has this cold weather been making you wish you could get outside and play in the dirt? Or perhaps you're looking for ways to improve your garden soil during the winter. Worm composting, or vermicomposting, is a good way to get both of these accomplished. In addition to producing compost, it's also a great way to put those kitchen scraps to use.

Getting started with vermicomposting is relatively easy to do. You can buy a kit, or you can simply use a plastic storage bin with holes drilled in the sides. A 10-gallon bin is a good size to start with. Drill ½ inch holes in the sides of the bin and lid, so the worms can breathe, and cover with window screening, so they don't escape.

A bedding material will need to be added to your bin. The bedding should be a nontoxic material that holds moisture, but also allows air to circulate. Some materials that can be used include newspaper (make sure to not use glossy paper), paper bags, cardboard, decaying leaves, or coconut coir. If using paper, tear it into half-inch-wide strips and soak in water for several minutes. Then remove the paper and wring it out, it should be slightly wetter than a moist sponge (this goes for any bedding material you may be using). Fluff the paper up and fill the bin halfway. The worms will eat the bedding, so more will have to be added over time. Make sure to keep the bedding moist, using a plant mister is a good way to do this. Finally, add a handful of soil to the newspaper, this will introduce microorganisms that will aid in the composting process.

Once your bin is set up it's time to add some worms. Red wigglers (Eisenia fetida) are considered the best worms to use. They like feeding on the surface of the soil, while the worms you typically find in the garden, or after a good rainstorm, burrow deep into the soil and are not good worms to for vermicomposting indoors. You will need around a pound of worms (about 1,000) for your bin.

After you've added your worms, it's time to feed them. They will eat almost any fruit and vegetable scrap you give them such as potato, carrot, banana, coffee grounds, and even eggshells (avoid citrus though). Do not feed your worms meat, dairy products, or oily foods. They won't eat them and the food will spoil. Feed your worms as needed, one pound of red wigglers can eat up to two pounds of food scraps a week. In a couple of months, you should have some worm compost to harvest.

To harvest your worm compost you can use one of two methods. First, with the divide and sort method, you stop feeding the worms and move your old bedding to one side of the bin and add fresh bedding and food to the other side. The worms will move to the new bedding and you can harvest your compost. A second method is the live-and-let-die option. You simply stop feeding the worms, eventually, they will die and you can harvest your compost.

Once you have your new compost it can be used in potting soil for your houseplants or store it to be used in your garden this spring.

Good Growing Fact of the Week: There are over 9,000 species of earthworms. So far only seven have been identified as suitable for vermicomposting, with the red wiggler (Eisenia fetida) being the most commonly used.]]>
How to Get Rid of a Mouse in the House Wed, 16 Jan 2019 10:44:00 +0000 Is your house full of visitors that annoy you, eat your food, and can lead to great exasperation and hollering? In-laws and extended family members aside; what I mean are the mice that have decided to move into your home for the winter months. In the wild, these creatures would look for shelter to survive the winter, and your house is a lot cozier than that dead log in the woods.

It recently happened in my household. My wife was wiping down the counter when she moved the blender. "Chris!" she shouted, "I think we have a mouse."

Sure enough, as we inspected the counter along the wall, there were mouse droppings. I quickly went to the pantry to see what damage the mouse had caused. Thankfully, as I rooted around the shelves there was no evidence of a mouse. So at least it hadn't found the pantry goods, yet.

Despite that blizzard in early December, we've had a pretty mild winter, which means a lot of critters have remained active outside. However, with our most recent snow and cold weather, some homeowners may currently be under the invasion of mice.

In my house, I catch and release spiders and all manner of other insects, but mice in the home should be of concern. Vermin such as mice, and especially rats, are a natural source of fear in humans due to their disease-carrying potential and these pests should be controlled.

Following the discovery of our new kitchen tenant, I had to brief the dog and cat that if they wanted to earn their keep, their job was to catch the mouse. After hearing my inspiring speech, they promptly laid their heads back down and went to sleep. Apparently, catching this mouse was up to me.

My mouse control strategy starts in the garage, where I tend to encounter them more often. In the garage, I have a live trap, which is often used for catching voles outside as it can hold up to 15 mouse-sized rodents. Check live traps routinely so any captured rodents do not suffer from starvation or exposure. Captured mice can be released or euthanized. The humane method for euthanizing captured mice is CO2 asphyxiation or cervical dislocation.

Indoors, we opt for snap traps. I baited two snap traps with peanut butter, placed one under the range, where I found more mouse droppings, and the other in the pantry, in case Stewart Little found the rodent jackpot. Place your traps along walls and near openings, which is usually the path most mice take.

If you have trap-shy mice, try baiting an unset trap and let the mouse take the bait without repercussion. After that, bait and set the trap.

University of Illinois Extension does have recommended poison baits, but I really discourage homeowners from using these. Once the mouse consumes the poison bait they typically hide in walls, vents, or attics as symptoms set in, where they will eventually die. As decomposition begins, the odor will make any nearby rooms or even the entire house unlivable. If the poisoned vermin escape outside and is eaten by a hawk or neighborhood cat, the poison would then be ingested and could potentially be fatal to the predator. Use wire mesh or steel wool to seal any openings that are as big as the diameter of a pencil and don't forget common utility openings such as dryer vents or the A/C hose.

Keeping a clean house, caulking and sealing entry points, and moving piles of leaves or excess mulch away from a home's foundation is the best way to limit entry to all pests. And if you are wondering, yes we caught our mouse. No thanks to the dog and cat.

Good Growing Tip of the Week: If you have a mouse skilled at stealing bait from the trap without triggering it, use a small string and tie a piece of dried fruit, nut, chocolate candy, or bacon to the bait location. You may need a third hand so you don't get yourself snapped in the trap.

New Garden Plants for 2019 Tue, 08 Jan 2019 09:47:00 +0000 Every year garden catalogs advertise new, exciting varieties of our favorite plants. Sometimes the options can be overwhelming, with each new addition sounding better than the previous. So how do you go about deciding which new variety to select? Fortunately, All-American Selections (AAS), an independent, non-profit organization tests these new plant varieties and names the best performers as AAS Winners.

Varieties that have never been commercially available are grown and evaluated for a full growing season in anonymous trials that are done by volunteer professional horticulturalists throughout North America. Judges look for significantly improved qualities such as earliness to bloom or harvest, disease or pest tolerance, novel colors or flavors, novel flower forms, total yield, length of flowering or harvest and overall performance. A variety needs to have at least two significantly improved qualities to be considered for an AAS award. There are six national winners for 2019:

Begonia Viking™ XL Red on Chocolate F1 produces vibrant red flowers and has large, uniquely colored dark leaves that maintain their color throughout the season. Plants reach 28-34 inches tall and maintain their mounded shape well and don't become leggy. These extra-large mounded plants are perfect in both landscapes and containers.

Marigold Big Duck Gold F1 produces large (3-inch!) golden-yellow flowers and continues to bloom throughout the season. These plants are 11-15 inches tall with deep-green foliage. These marigolds can be used almost everywhere, in beds and containers; in landscapes as mini hedges, back of the border plants, or even as a filler in new perennial beds.

Pepper Just Sweet F1 is a snacking pepper that produces vivid yellow 3-inch fruits that are sweet with nice thick walls. The plants are also vigorous growers, growing up to 36 inches tall and 15 inches wide, but don't need to be staked because they've been bred to have a strong bushy habit.

Petunia Wave® Carmine Velour F1 is the newest color of the popular Wave® petunias. Large 2-2.5 inch carmine rose flowers cover these spreading plants that rarely need deadheading. Plants are 6-8 inches tall and act like a ground cover, spreading 3-4 feet. They are excellent performers and do equally well in containers or hanging baskets and in the landscape.

Tomato Fire Fly F1 produces super sweet pale-white to pale-yellow round fruits that are less than 1 inch in size and weigh about 1/2 oz. that are perfect for snacking and salads. These are indeterminate plants and need to be supported as they grow 5-6+ feet. They also have good disease resistance and ripen 80 days after transplanting.

Tomato Red Torch F1 is a striped oblong tomato with 1.5" long fruits that weigh about 1.5 ounces and is a very prolific early-season producer. Plants have excellent tolerance to environmental stresses like heat and harsh growing conditions. Plants are indeterminate and grow 5-6' tall (so they will also require support). Fruit ripen 60-70 days from transplanting.

AAS also names regional winners. This year there was one regional winner for the Great Lakes (Illinois' region):

Watermelon Cal Sweet Bush is a short internode watermelon, meaning it has a compact growth habit, reaching only 14-18" long! Each plant yields 2-3 sweet, crisp fruits that weigh 10 -12 pounds. This watermelon is a great choice for those of us with limited space, and can even be grown in a container.

Whether you're an experienced gardener or just starting out, make sure to check out these and other AAS winners. To see a list of all of the winners dating back to 1934, visit the All-American Selections website at:


Good Growing Fact of the Week: Plants with an F1 indication means they are a first generation hybrid plant. Plant breeders take parent plants with desirable qualities and cross them and produce hybrid plants (F1). The best of these offspring are then selected for commercial production.

Garden Resolutions for 2019 Wed, 02 Jan 2019 15:39:00 +0000 A new year brings the opportunity for a fresh start. For a gardener having the year switch in the middle of winter can be difficult. Right now, I am full of ideas and goals as I am once again missing my near-daily commune with soil. If it were in my power to change when we celebrate New Year's, I would suggest March 1.

I can make all the plans in the world, but it's cold outside, so those plans have to wait. And as things that get tossed on the back burner so often do, that is where they remain. As the winter trudges onward we get busy with all the facets of life. What better way to stick with your New Year's resolutions than to share them with all the world! (Actually, research shows when someone tells others of their intentions, they tend not to follow through on them. I'm enlisting you all as my accountable-a-buddy)

  1. Plant carrots, right now! I learned in 2019 that you can plant carrots in January and get germination. Once we get around to the longer days in late February the carrot seedlings take off and you can get early spring carrots. All you need is some type of season extension device. It could be a low tunnel, cold frame, or high tunnel if you have one.
  2. Do something about my backyard. I really do like my backyard, but it definitely needs some attention this year. Right now, my proposed plan is to install a dry creek bed to handle excess drainage from around the house and build a very low terrace in my southern landscape bed with natural stone. (Scavenged stone preferably. Have you seen how expensive decent landscape rock can be?)
  3. Continue to share our bountiful harvest. Each year University of Illinois Extension Master Gardeners grow and donate fresh produce to local food pantries. It is an incredible experience! If you want to be a part of improving your community we are offering Master Gardener training in 2019. Get in touch with me or your local Illinois Extension office. They know how to track me down.
  4. Walk more! If there is one thing my sanity craves, it is to be able to get outside. Sometimes with our modern lifestyles, that just doesn't happen as often. To help encourage us all, University of Illinois Extension Master Naturalists will host a National Trails Day event on June 1. We're still in the planning process on this one, so look for a future article plugging this exciting new event.
  5. Save the planet! Okay, that may seem like a lot to bite off, but we are facing some serious issues with climate change. To make a difference, everyone is going to need to do something, big or small. My question to you is, how can horticulture and Extension help make our Illinois communities more sustainable. If you'd like to weigh in on this take my survey at It is only three questions and should take less than five minutes to complete.
  6. Never stop learning. This is why I love my job. Once you start down the path of science and nature, you'll realize this is an endless journey and one of the greatest pursuits of humankind. Your local Extension office undoubtedly has opportunities for you to keep on learning. In Macomb, we will be hosting our 23rd annual Gardener's Day on April 6.

Okay, it seems unlikely that New Year's is going to be moved closer to spring. I don't quite have that level of influence as Pope Gregory did in the 1500s when he created the Gregorian calendar. But perhaps Illinois Extension can help you with some of your New Year's resolutions. Check us out online to see what we can offer.

Good Growing Tip of the Week: Carrot seed is tiny and often requires thinning because too much gets sowed. Consider using larger pelleted carrot seed or seed tape to eliminate the need for thinning carrot seedlings.