Dr. Dean Krauskopf
Spring is here and Dean is back! The Gardening Show’s 2019 season begins Saturday, April 13th at 5 pm on News/Talks 760 WJR.
The Gardening Show
Michigan Strawberries are becoming available. Here’s a list of Pick-Your-Own farms.
Critters causing problems? Here’s information on wildlife management for farmers that might also work for homeowners.
How has the weather influenced insects? This article by MSU’s Dr. Christina DiFonzo focuses on field pests but could be extrapolated to your yard and garden.
Cool and wet equal Botrytis.
Not going to plant part of your garden? The thing about growing a cover crop on that area.
Stay away from Poison Hemlock and Wild Parsnip.
Fletcher scale can be found on yews, arborvitae and a wide range of other plants.
Don’t park under a Magnolia tree infested with scale.
Fletcher scale can be found on yews, arborvitae and a wide range of other plants.
Elaine in Bloomfield Hills is battling a tuber forming weed in her myrtle. The first step is to identify the weed. To control the weed you must kill the tuber which can only occur in the fall. Three applications to the leaves of the weed, two weeks apart beginning in mid-September, using products containing triclopyr or glyphosate with a herbicide wick/rope/sponge applicator should work.
Timothy in Novi wondered about watering trees newly planted in a berm.
Tim in Temperance may need to move his large quince bush. I would allow some of the young shoots at the outside of the shrub to root and transplant them to a holding area this fall after we’ve had some killing frosts. Here are some transplanting tips. (More information)
Russ in West Bloomfield‘s tenants were concerned that fertilizers and lawn care products posed a risk to their pets. Check the labels – most materials suggest keeping pets and people off the treated areas for 24 to 48 hours after application while other materials should be watered in and then the grass allowed to dry. To reduce exposure to fertilizer you can grow a very satisfactory lawn applying slow-release fertilizer only twice per year. Spot treat weeds instead of using a weed and feed or lawn wide applications. Lastly,you can wash the animal’s paws after they’ve been on the lawn.
Dave in Howell was dealing with standing water even though a French drain had been installed. It’s possible that drain was plugged or too small for the amount of rain we’re getting. Another option would be to install a rain garden.
Kenny in Macomb was fighting moss and weeds in his yard and weeds in his mother’s lawn. The first step is to identify the weeds and control measures here. Second, concentrate on increasing the vigor of the turf using the information here. Getting rid of the moss may be difficult because of the shade from the neighbor’s trees, however, if you can’t work with the neighbors to thin the trees using a more shade tolerant grass might help.
Don wanted a certified organic insecticide with a broad range of control. Products contain Spinosad fit the bill.
Dan in Jackson wondered why his begonias weren’t growing. Begonias do well only after night temperatures reach 60 degrees of higher and we haven’t gotten there yet.
Kim Parr, Director of the Crocker House Museum and the Macomb County Historical Society was my guest talking about the annual Garden Walk and Breakfast, Saturday, June 29, 9 am – 4 pm.
USDA 2012 Plant Hardiness Zone Map is now interactive and much more detailed.
A new variety of Callery pear, Chastity, that is 99.14% sterile.
Integrated Pest Management information from homeowners from MSU.
Want to grow lavender? Here are tips from MSU and an online course will be available soon.
Yucca plant bug can cause severe damage.
Love garlic? Garlic scapes are wonderful.
Something was digging holes in Rose from Warren‘s mulch. Sounds like 13-Lined Ground Squirrels.
Al in Canton wondered about using a weed and feed product on his lawn. I suggested identifying the weed and spot applying an appropriate weed killer at the proper time.
Edie in Grosse Pointe Woods wondered how deep maple roots can penetrate. Most roots are found within the top 3 feet of the soil but can penetrate deeper.
The problem for Jamie in New Baltimore wasn’t how deep roots penetrate, but what to do with roots growing at the surface. The first step is to identify the tree. Here’s information from Texas A and M on how to change the grade around a tree.
Sandy in Irish Hills transplanted a rose and now the plant grows long shoots but doesn’t flower. I think the scion died and the undershoot has taken over. The way to tell is to look for 7-leaflet leaves along the entire shoot. Hybrid tea roses have either 5-leaflet or 3-leaflet leaves.
The peonies at Nichol‘s arboretum are at about 40% bloom.
Keep an eye out for spittlebugs.
Plant leaves turning purple? Could be phosphorus deficiency caused by cold.
Lace bug damage on Silver linden.
Scarlet Oak Sawfly attacks a wide range of oaks.
Lumpy bags on your plants? The time to control bagworms is coming up.
Four-Lined Plant Bug damage is starting.
Vegetable scouting app from the University of Kentucky.
Grace in Utica wondered if when she could trim the outside branches of her silver maple to increase light to her turf. You can prune almost anytime as long as you follow proper techniques however, I would suggest contacting a certified arborist to see about thinning the tree which will improve tree health and increase light penetration.
Joe in Canton was concerned about the dark spots on his tree. Certain diseases impact specific trees so identifying the tree under attack is the first step. Oak anthracnose mentioned above is a possibility while if it was a maple later in the year I would suspect tar spot. In either case, contact the MSU Plant and Pest Diagnostic Laboratory about submitted a sample.
Eileen in Macomb wanted to control poison ivy on a lake bank. Poison ivy is very difficult to control because it is a perennial and you have to fill the root. Applications in September, October, and November if there is still active leaf surface present are most effective. Because all these materials are very water soluble, use extreme care if spraying so no material gets into the lake, runoff, if applied too close to a rain event, is also to be avoided. I suggested using a wipe applicator.
David in Clay Township is battling 13-Lined Ground Squirrels which isn’t easy. I would suggest using repellents first and then traps and/or baits. If you want to make bait stations use 1 1/2 inch of PVC pipe instead of the 1/2 inch as suggests here for vole control. As Bob in Petersburg and I discussed fumigants should never be used around inhabited buildings.
Find something strange? Here’s where to report it; Great Lakes Early Detection Network, hosted by the University of Georgia and the Midwest Invasive Species Information Network, hosted by Michigan State University.
Some interesting preliminary work on developing bio insect repellents.
I posted information about crayfish making mud chimneys in lawns last week. Here’s information about the Michigan species.
Check trees (especially honeylocust) and shrubs for Calico Scale crawlers. If you see them it’s time to apply controls.
Videos for home fruit growers from the University of Kentucky.
Judy in Chelsea is fighting Canada Thistle, a non-native extremely hard to control weed. Continued mowing or using burn-down herbicides to remove the leaves of the plant will reduce its vigor. However, control is only achieved by killing the roots which means applying a translocating herbicide multiple times in September and October.
I think Mary in Farmington‘sGolden Vicary Privet will come back very well after suffering winter kill. Just prune out the dead and winter damaged branches and the new shoots will grow very quickly.
Jim from New Vienna Ohio wondered about adding organic matter to clay soils. The ease of the movement of water and oxygen into soil is determined by the proportions of large and small pores. The ratio of large (quick movement of water and oxygen) pores to small pores (slow water and oxygen movement), the infiltration rate, is determined by the proportion of sand, silt, and clay (the soil texture). Adding organic matter does two things; first, large organic particles in the soil increase the proportion of large pores. Second, as organic matter breaks down, the humic acids and other chemicals released act like glue to bind small soil particles into large ones which changes the soil structure to increase the proportion of large pores. The problem comes when this porous soil is surrounded by unamended clay. Here, water moves very quickly through the large pores until it hits the small clay pores and builds up (I call it the bathtub effect). The large pores are filled with water which prevents roots from getting oxygen and they literally drown. Even deeply amended beds are susceptible during heavy rain events or overwatering. Adding drain lines will prevent the problem or in most cases, suggest planting into the native clay soil so that water doesn’t infiltrate so rapidly into the root zone. Don’t dig or otherwise work clay roils when they are too wet.
The Ann Arbor Garden Walk will be held June 8, 10-4.
The Mount Clemens Crocker House Garden Walk and Breakfast will be held 9-4, June 29.
Here’s a course on mushroom identification.
Time to plant? Check MSU’s Enviorweather for soil temperatures Usually soil temperatures 4 inches deep have to be 60 degrees or higher for best seed germination.
Native Michigan Bees and the Flowers They Love, June 8. Gennessee County MSU Extension, Register here.
Cool or warm, wet weather means slugs.
Potato leafhoppers have been showing up after strong Southern winds.
Looking for really cool photos for your monitor wallpaper or screensaver? Here’s some from the USDA.
Bacillus thruingiensis (Bt) can help control gypsy moth and other caterpillars.
Warm wet weather is ideal for Botrytis especially on peony.
Maple leaves all over your lawn? Probably maple petiole borer.
Volutella blight on boxwood.
Great bulletin on shade tree anthracnose.
Kathleen in Milan‘s “Beauty of Moscow” lilac hasn’t budded out. Even though it’ listed as hardy to Zone 3, I’m leaning toward cold damage from the -20-degree temperatures in January. Another possibility is water standing around the roots due to our heavy rains.
Kathy in Clinton Township wanted to identify Michigan trees. I suggest the National Audubon Society’s and Peterson Field Guides Eastern editions. Trees in Michigan by Linda Kershaw (Lone Pine Press) is also useful. MSU’s Dr. Robert Schutzki has written an excellent bulletin, here’s a site for the UP and a great app.
Here’s the latest information on late blight resistant tomato varieties.
Here’s a great guide to controlling fruit insects and diseases.
Want to become USDA Certified Organic? Here’s how.
Interested in biodegradable plastic mulch? Here’s information.
Asiatic Garden Beetle grub damage is starting to become a problem.
Watch out for European Paper Wasps.
Bristly Rose Slug is becoming a major problem.
Look out for Wild Parsnip and Poison Hemlock.
Pick the right spot for Dogwood Trees.
That slimy, black stuff may be Nostoc.
Rose from Upper Sandusky, Ohio wondered about the shoots coming from the understock of her tree peony.
Bob in Southgate wanted to get rid of the dandelions in his yard.
Dave in Wyandotte had saved peach and plum pits and apple seeds and wanted to germinate them.
According to my guest Bob Tritten, MSU Fruit Educator, this year’s fruit crop looks OK but is developing slowly. Here’s a list of fruit growers in Southeast Michigan.
The MSU Horticulture Gardens 2019 Plant Sale is Friday, May 17th (for members only!) and Saturday, May 18th for the public.
Flower Day at Detroit Eastern Market is Sunday, May 19th.
More information on Spotted Lanternfly.
Keep an eye out for black cutworms.
Boxwood Leafminer Flys will be emerging soon.
Teddy in St. Clair Shores is fighting Creeping Charlie with some real challenges. There are only two opportunities for controlling Creeping Charlie, when it’s flowering and then the best time in the fall. You shouldn’t apply any material when the ground is saturated or there is free water because these materials are very soluble and overspray may move into the water. Make sure you apply the recommended amount by measuring the area to be treated and then follow the directions exactly. The most effective control material contains triclopyr but it’s also the most expensive. Keep pets and children off the treated area for 24 hours or until it’s completely dry and for a day or two you can wash your dog’s paws after its been outside. Creeping Charlie can spread a long way so talk to your neighbors about everyone treating at the same time.
Don in Lansing‘s isn’t getting the amount of fruit he should because the fruit drops off early. Here’s excellent information on growing apples from the University of Maine that discusses fruit drop problems and here’s information from other universities (Article 2, Article 3) Here’s information on how to prune peach and plum trees and an excellent guide to disease and insect control.
Releaf Michigan’s Big Tree Hunt nominations must be in by September 13, 2019. Here’s how to enter and here’s a list of Michigan’s record trees. Here’s a smartphone app that will help identify the tree or you can go here.
Most of these broad-spectrum vegetable fungicides are labeled for commercial use, however, some are available to homeowners.
Are you handling your garden produce in a safe manner? Here’s how commercial farmers do it.
Tree moats and volcano mulch, great ways to kill trees.
Calico scale is becoming active which isn’t a good thing.
Positive news about Spotted Lantern Fly?
Mike in Novi called to remind everyone that a window for controlling Creeping Charlie is opening soon.
Moss in their lawns was on the minds of Kenny in Macomb and Billy in Hillsdale. Moss thrives in areas with too shady for grass to grow vigorously so the first approach is to trim trees and shrubs that are shading the area. I always suggest consulting an arborist before doing major tree trimming. Moss grows well in wet areas where grass isn’t competitive so raising the height of your lawn by applying thin (1/4 inch) layers of screened topsoil repeatedly. A final approach is to install drain lines.
The shrubs in Tom’s Livonia yard were being eaten by deer. If your putting in a new landscape or replacing plants here’s a list of deer-resistant ornamentals. Vertical and horizontal fence barriers may help. Repellents can be effective but you must reapply them frequently and you may need to try several before finding one or more that work.
Kathleen‘s female dog was causing dead spots in her lawn. The best approach is to teach the dog to use rocks or mulch to cover one area in the lawn and train the dog to do her business there. If the spots are small you can allow the surrounding grass to cover them, lightly raking the area and a little fertilizer will speed up the process. The combination seed and mulch products works well, however, the new grass may not be the same shade of your older lawn.
David in Warren wanted information about controlling crabgrass after it’s germinated.
My guest next week will be Lara Edwards, Programs and Development Coordinator, ReLeaf Michigan, who will be talking about their Big Tree Hunt.
When should I plant? Here’s information on frost-free dates in Michigan.
Don’t freak out about the “Kissing Bug”, an excellent article by OSU’s Joe Boggs.
Four-Line Plant Bug will be showing up soon.
Heavy seed loads on maples: Late freeze effects or synchronous masting?
Aliens attacking my plants? Probably a type of rust.
Eleanore of Bloomfield Hills is having problems with pachysandra Soil pH controls that availability of iron to plants. Simple pH testing kits work well – follow the directions exactly for best results. I have found the electronic pH testing equipment that you stick into the soil a bit variable due to different soil moisture contents. Iron chelate sprays can give you a quick indication if soil pH is the problem but aren’t a solution. If pH is the cause of the yellowing there are a range of ways to correct it.
Dan is having disease problems with his pines. The first step is to positively identify the cause since control measures and timing vary with the disease. Once the casual organism is identified, there may be several brands that contain the recommended active ingredient.
Laura from Northville was concerned browning of white pines up North. White pines are very susceptible to salt spray damage and it’s especially noticeable on the sides of the trees facing the road. Another problem is the long periods of drought we’ve been experiencing.
Peggy in Belleville‘s euonymus is thinning out and apparently infested with euonymus scale and crown gall. Fortunately, both problems can be improved by pruning out the old, infested stems and allowing the new shoots to take over.
Larry in Rockwood wondered how to prune his junipers.
Barb in Brighton was being plagued by what looked like horns growing out of the ground that smelled terrible and attracted hordes of flies. Not that latest low budget horror film but probably skunk cabbage, which while smelly is a fascinating plant that provides bees with must need pollen early in the Spring. A systemic herbicide applied late in the fall with control growth.
Larence in Clinton Township had what sounded like Oystershell scale on his lilacs.
Ann in Ann Arbor wanted to get rid of English ivy taking over her lilacs without using conventional herbicides. Digging up as much of the ivy roots as possible without harming the lilac root is the first step. Then I would put down heavy duty, woven weed mat (not plastic sheet that won’t allow water and oxygen to move into the soil). Shoots will emerge at laps and other gaps so using a contact herbicide (some are organic) whenever they are seen will eventually starve out the root.
My guest, Melissa Rugh, an occupational therapist and athletic training at the DMC Rehabilitation Institute of Michigan and an avid gardener suggests a wide range of approaches to preventing and treating gardening injuries. Here is more information.
Lilies (including Easter Lilies, Daylilies, Stargazers, etc) are very toxic to cats.
Nancy from Farmington Hills wanted information on how to solarize her garden soil to kill weeds and some pathogens. Here’s information from the University of California, however, be aware that because Michigan has less sun and cooler temperatures you need to use black plastic instead of clear.
MSU’s Heidi Lindberg recommends that you pile organic refuse from Spring cleanups of perennials and ornamental grasses on top of your compost pile to allow beneficial insects that overwinter in this material time to emerge.
Everyone who sells non-native aquatic plants, crayfish, snails/mussels, turtles, amphibians and other aquatic organisms in Michigan must be registered with the State of Michigan and display their license and here are the aquatic species prohibited from sale in Michigan.
The Insecticide Options for Controlling Emerald Ash Borer fact sheet has been updated. Here’s the latest information.
Boxwood blight is a new threat but old insects, diseases and environmental issues still cause problems.
For all the Buckeye listeners here’s how to get Growing Degree Day information for your area.
Dave in Mt Clemons called about transplanting and dividing peonies. Late August or early September is the optimum time to move/divide the plants because the root system will become established in the new location before the ground freezes. However, peonies can be moved/divided anytime if necessary. Just remember that the root system won’t be fully developed for two growing seasons to pay special attention to watering. Contrary to what it sounded like, you can fertilize peonies, especially ones becoming established after the flower has bloomed.
Henry from St Clair Shores was trying to determine if there was any way to save a large number of mature pines up North. From the symptoms he described it sounds like white pine blister rust, however, a true diagnosis should be done by a plant pathologist.
Spotted Laternfly isn’t here yet but it’s coming, and it likes lots of our favorite plants. Here is more information.
The Michigan Gardener is a wonderful source of gardening information written by local experts and it’s free! Get a copy at your local greenhouse or nursery or go here.
Time to apply crabgrass pre-emerge? Here’s a great article by MSU’s Dr. Kevin Frank. Dr. Grank mentions using forsythia as an indicator plant; however, if your forsythia lost it’s flower buds due to last winter’s cold, GDD Tracker will help.
Not sure if crabgrass is the problem? Go here to identify what’s in your lawn.
White Pine Weevil will be showing up soon.
Purple Deadnettle is not one of my favorite flowers.
Soil Mining Bees are important pollinators and aren’t aggressive. Here’s a great article.
Steve from Swartz Creek wanted to get rid of Marmorated Stink Bugs in the home. Use a vacuum cleaner or a light trap.
Steve also wanted information on stopping suckers (shoots) on the bottom of trees. You can physically remover them (best done when they’re very small) or use a material containing Ethyl 1-naphthaleneacetate. There are two products labeled in Michigan Tre-Hold made by AMVAC Chemical Corporation and Sucker Stopper RTU produced by Monterey Lawn and Garden. Follow the instructions so the material will be effective without harming the tree.
Considering hiring an arborist? Here’s how.
Sweet, hot, chilli, chilli, chile? Confused about peppers? So am I but MSU’s Ben Phillips will sort everything out here.
Thinking about adding a new landscape or redoing an older one? Consider incorporation wild-fire resistant plants.
Colleen from Rochester called about what sounded like black knot on her cherry tree. I misspoke in saying the disease is caused by bacteria, in fact, it is a fungus.
Bethany from Mount Clemens wanted to find a new home for her heirloom peonies while Ralph in Grass Lake wondered how to prevent the flowers from bending over after a rain. We talked about putting a cage around them, I tie them up using twine around the entire clump or putting a piece of 4 x 4 netting over the shoots just as they emerge and then raising the netting as the plant elongates. I forgot to mention that stems may be weak if the clump is too crowded so dividing the plant will increase stem strength. Here’s more information on peonies. A very large peony collection is located in UM’s Nicols Arboretum.
Chase the winter blues, get great gardening ideas and maybe a few plants at the MSU Student Horticulture Association’s 30th Annual Spring Show and Sale in the Plant and Soil Sciences Building on MSU’s campus. The show is open from 9 am until 6 pm on Saturday, April 13 and from 10 am until 4 pm on Sunday, April 14. For more information, click here.
Boxwood blight has been confirmed in Michigan. Here’s more information on this very serious disease from MSU Extension.
Spotted Laternfly isn’t here yet but it’s coming, and it likes lots of our favorite plants. Here’s more information.
The Michigan Gardener is a wonderful source of gardening information written by local experts and it’s free! Get a copy at your local greenhouse or nursery or click here.
Time to apply crabgrass pre-emerge? Here’s a great article by MSU’s Dr. Kevin Frank. Dr. Frank mentions using forsythia as an indicator plant; however, if your forsythia lost it’s flower buds due to last winter’s cold, GDD Tracker will help.
Not sure if crabgrass is the problem? Go here to identify what’s in your lawn.
Don’t prune oaks to prevent the spread of Oak Wilt.
This publication from the University of Georgia lists a wide range of plants, however, before buying check to see if they are hardy in the Midwest.
CONTACT DR. DEAN KRAUSKOPF