AYGQ: LIVE – July 2026 Session Links and Resources

Fruits & Vegetables

Tomatos

Q-Why are my tomato plants wilting?
A-The current environmental conditions are causes of fungal pathogens, humidity, and heat stress. Refrain from watering during the heat of the day. Water the ground around your plant and keep overhead watering to a minimum.  Photos will be needed for diagnosis.  Another possibility is herbicide drift.  Insects on tomatoes this time of year are aphids and hornworm caterpillars.  Make sure you have a good mulch cover to help with the heat stress.

• Plant Disease Diagnostic Clinic – wisc.edu
• Key to Common Problems of Tomatoes – umd.edu
• Aphids – wisc.edu
• Hornworms – wisc.edu
• Herbicide Damage – wisc.edu

Peas

Q-Peas are dying from the roots up two years in a row.
A-Get the soil tested and rotate crops in the garden.  It’s difficult to diagnose without photos. Peas are a cool crop plant. Seed corn maggots will attack the seeds.

• General Approaches to Insect Control – wisc.edu
• Handbook of Pea Diseases – wisc.edu
• Soil Testing – wisc.edu
• Seed Corn Maggot – umn.edu

Anthracnose on Cucumber

Q-Suspects anthracnose on cucumbers growing in a straw bale.  Applied a copper fungicide.
A- Photos are needed to confirm the anthracnose diagnosis. Generally speaking, fungicides are for preventive use rather than curative.

• Plant Disease Diagnostic Clinic – wisc.edu
• Vine Crop Disorder: Anthracnose – wisc.edu
• Straw bale gardening – missouri.edu
• Disease Resistant Vegetable Varieties – cornell.edu

General Gardening

Creeping Charlie

Q-What native plants would you recommend that will compete with Creeping Charlie?
A-First remove as much Creeping Charlie as possible.  Pull, cover with cardboard or apply compost.  If you’re just turning the soil over, use a pre-emergent herbicide. Something like Preen is good to neutralize some of the weed seeds and give you a fresh start in those spaces. Then go back in with good ornamentals. Some good natives are little bluestem, big bluestem, switchgrass, Indian grass, or Pennsylvania sedge. Once they’re established, they’ll crowd out a lot of weeds, especially if you’re planting them two foot on center.  Start with small plants like plugs versus sowing in small, manageable sections.  Fall is the best time for establishment.

• Creeping Charlie – wisc.edu
• Landscaping Alternatives – wisc.edu

Bee Balm (Monarda)

Q-When is the best time to divide and move Monarda (Bee Balm)?
A-Typically early fall or spring.  You want to have a good six weeks of decent growth time before you get into the hard frost. One little tip, if you are planning your garden in fall for a spring application, mark the locations in the fall.  Put little flags or little stakes, that will remain over the winter. In the springtime, you will know where to plant.

• Monarda – ncsu.edu

Easter Lily

Q-An Easter Lily planted in the ground at least three years ago produced white blooms.  This year it has at least 19 blossoms and they are red.
A-There is a phenomenon where plants sometimes go through a mutation.

• Easter Lily – wisc.edu

Applying Compost

Q-Is it too late to apply compost?
A-Compost can be applied anytime of the year.  The nature of compost is soil enrichment whether it’s your lawn or your garden. Compost also has moisture holding capacity, which is great this time of year.  Make sure you know the source of your compost because the worst thing you can do is bring in more of those problematic weeds that you’re trying to control.  

• Making and Using Compost in the Garden

Houseplants

There were no questions on houseplants this month.

Insects

Cabbage Worms

Q-Are cabbage worms likely to invade the same area every year in a garden. I’ve gardened in the same spot for 6 years, and this is the only year they have been here. Should I expect them again next year?
A-With things like cabbage, and when I think of cabbage worms, there’s all sorts of caterpillars that will feed on the above-ground parts, and those are basically moths or butterflies of one species or another, and they’re pretty mobile. If you have them in one given spot, you’ll probably continue to see them around, although their populations may fluctuate from year to year.

If you’re talking about things damaging the roots, cabbage maggots come to mind and often they go through these cyclical patterns.

• Imported Cabbage Worm – wisc.edu
• Cabbage Maggot – wisc.edu
• Degree Days for Common Insect Pests – wisc.edu

European Earwig

Q-European Earwig populations have exploded in the past three years.  Can I now expect them every year?
A-Earwigs are not native to Wisconsin. They showed up in the state decades ago. And in some areas, it was very noticeable at first, and then things kind of quieted down a bit. Now, because earwigs really thrive under damp conditions, the weather will probably be the biggest factor. Dry years are not going to be good for earwigs and slugs. If we have moist years, that’s generally going to be good for earwigs. If you have them in your area, they’ll probably always be around. But in many cases, they don’t like to be out in the bright sun.
But if you think they might be doing damage, go out after dark with a flashlight and you’ll see them climb up onto plants. You could also try a little bit of trapping. One approach is to use an empty tuna can or something like that. Dig a little pit and put it down at ground level and fill it up with soapy water. Probably not great for overall control, but for monitoring. Another easy thing is if you have an old shingle, old newspaper, just a piece of plywood.  Put that down on the ground. It’s going to create a damp hiding spot. Then flip that over and see if they’re under there and spritz them with soapy water or something like that to take care of them.

• Earwigs – wisc.edu
• Slugs – wisc.edu

Milky Spore for Grub Control

Q-What’s the current recommendation on Milky Spore for grubs in Wisconsin?
A-I do see it out there at the garden stores. I do not recommend it. There is not any good solid scientific evidence to back it up. Often when folks contact me about issues with Japanese beetles, my first question is along the lines of what plants are you trying to protect, and that’s really where you should focus your attention. If your concern is the rose bushes or your fruit trees and some ornamental plants, target those plants.  With any grub control product, be it organic or conventional, one critical thing is you need to water it in to move the ingredients down, so it works. If you apply it and it just sits on the thatch layer, it will not reach the grubs.

• Japanese Beetles – wisc.edu
• Biological Control – missouri.edu

Geraniums and Japanese Beetles

Q-Is there any scientific evidence that geraniums repel Japanese Beetles?
A-Zonal geraniums have a substance in the leaves that causes the Japanese Beetle to become intoxicated when they feed on it. So, if you can imagine if you are an intoxicated beetle, you’re lying on the ground or on a rock, it’s a sunny day, you’re desiccating, or a bird might eat you.  Putting one or two of the zonal geraniums in your landscape is not going to repel them.

• Zonal Geranium – ncsu.edu

Controlling Aphids with Ladybugs

Q-Is ladybug release considered an effective organic landscape treatment for aphids?
A-It could depend on the species you’re obtaining. If it’s a species that is not native to Wisconsin, that’s not necessarily a great situation. Also, it could depend a bit on the life stage you’re getting. If you are purchasing larvae, they don’t have wings. They cannot really leave all that easily, and so if you put larvae on a given plant, they’re just there, versus if you purchase pupae or adults from a vendor. 90% of the adults fly away. Think of this as a one-time use of a biological. A better alternative would be lacewings, especially as eggs. Cost-wise, they may be cheaper than shipping larvae or adults. Those eggs are going to become larvae which can’t fly. They’re going to walk around and feed on things. They are generalists.

• Ladybug Release – ucanr.edu
• Lacewings – umn.edu

Leafminers on Beets

Q-How to control leafminers on beets.  They were sprayed with a copper fungicide. 
A-A fungicide would be for disease, not insects. Removing the leaves is an option, but you tear off a leaf and then a week later additional leaves have them and before you know it, you have almost no leaves left on the plant.  Preventing damage is probably going to be the best long-term approach. One option would be to use a floating row cover or fine mesh netting. Practice crop rotation and good garden clean-up.

• Vegetable Leafminers – wisc.edu
• Floating Row Cover – wisc.edu

Lawns

There were no questions on lawns this month.

Plant Diseases

There were no questions on plant disease this month.

Trees & Shrubs

Japanese Maple

Q-Japanese maple tree tag says to plant… dig the hole twice as wide as the root ball but then mix in compost with the native soil.
A-The best advice is basically return the same soil you took when you dug the hole as backfill, rather than heavily amended soil, especially when you’re dealing with clay soils, because that amended backfill creates an interface there with the native soil.  If you have clay, your planting hole is just going to fill up with water when you do that, and the roots are going to die.  Rough up that soil on the sides and bottom of the hole so it has a little bit more porosity than just a smooth surface.  And again, don’t amend that backfill or minimally amend it with granular organic fertilizer.  Mulch properly. Don’t volcano mound.

• Japanese Maple – ncsu.edu
• Proper Tree Planting – wisc.edu

Dwarf Trees for Shade/Privacy

Q-What varieties of dwarf trees are recommended for privacy and shade in Southwest Wisconsin?
A-Do they mean true dwarf, or do they mean under canopy? Because my go to under canopy tree will always be a serviceberry. Others would be pagoda dogwood or redbud. Consider-right plant for the right spot.  I usually don’t see too many insect problems on serviceberry. There’s plenty of things that can feed on serviceberry insect-wise, but I usually don’t see significant issues. Same thing with the redbuds. The biggest problem that I see with these trees in the landscape is sun scald and winter burn, so make sure that you’re protecting those trunks in late fall, really November through late March or April.

• Serviceberry – wisc.edu
• Proper tree planting – wisc.edu
• Eastern Redbud – wisc.edu
• Pagoda Dogwood – umn.edu
• Winter Burn – wisc.edu
• Choosing the right landscape plants – wisc.edu
• Sunscald in young trees – wisc.edu

Watering Trees During Drought

Q-Should a soaker hose be used around an old pear tree? This pear tree has lots of pears on it and don’t want to lose it because of the hot weather and possibly dry weather.
A-Concerns right now with that pear tree is if it’s already dried out and it’s already got heat stress, that it might experience some fruit drop. Supersaturating it right now, soaker hose or otherwise, may or may not allow it to catch up. Here is a good recommendation for trees in general.   New trees need about 10 gallons of water a day.  So, you’ll often see soaker bags, or 5-gallon buckets with a small hole in the bottom so you get some trickles. New trees and planting need saturation so that they have a good amount of water in their structure within the tree itself. But we also want to encourage these plants to dry out a little bit, because if you water, water, water, water, water, the result is root rot.  Soaker hoses may not apply enough water and only in one location.

• Gardening for Weather-Extreme Heat – wisc.edu
• Growing Pears in Wisconsin – wisc.edu

Weeds & Invasive Species

Chickweed

Q-How to control Chickweed around Hosta plants?
A-Hand pulling.  If it’s a Hosta garden, encourage more Hosta growth, because they’re the perfect type of plant to layer and layer and layer. There are 10,000 different varieties of Hostas which make a really interesting garden. Get bigger ones and taller ones and shorter sizes, varieties, colors, and just carpet bomb it. That will crowd out just about anything else that wants to grow there.  Mulching will help. 

• Chickweed – wisc.edu
• Hostas – umn.edu
• Mulch – wisc.edu

Wildlife

Wildlife Ecology Factsheets

• UW Wildlife Ecology factsheets – wisc.edu