AYGQ: LIVE – May 2026 Session Links and Resources

Fruits & Vegetables

There were no questions on fruits and vegetables this month.

General Gardening

Cannas

Q-Is it OK to plant canna rhizomes in pots outside now, or should they be started indoors?
A-Cannas should be planted after soil temperatures reach at least 55–65°F. Make sure you are testing in the area where you will plant. They can be started indoors or grown in containers. Because they are not winter hardy in Wisconsin, rhizomes should be dug after the growing season, dried, and stored in a cool (40–50°F), frost-free environment for winter.

• Starting canna rhizomes indoors – iastate.edu
• Growing cannas – umn.edu
• Storing tender bulbs for winter – wisc.edu

Sidewalk Salt Exposure

Q-Can plants grow in areas with heavy salt exposure?
A-Plants can survive in salt-affected areas, but success depends on species selection and soil management. Salt-tolerant plants such as certain sedges and shrubs may perform adequately. Improving soil with compost, promoting good drainage, and leaching salts with water can help mitigate salt injury. Pennsylvania sedge, black chokeberry and serviceberry are salt tolerant to a point.  In the spring if it hasn’t rained, water to help dilute the salt faster.  Soil testing is strongly recommended to understand starting conditions. 

• Salt tolerant landscape plants – wisc.edu
• Soil Testing – wisc.edu

Sowing Seeds in Dry Conditions

Q-Can seeds be successfully planted in dry conditions?
A-Seeds require consistent moisture to germinate. In dry conditions, supplemental watering is necessary to maintain evenly moist soil without crusting or displacement. Wildflower seeds are often better planted in fall to allow for natural stratification. 

• Plant dormancy – wisc.edu
• Fall is for planting perennial wildflower seeds – cornell.edu

Common Milkweed

Q-My common milkweed grows but doesn’t flower; why?
A-Lack of flowering in milkweed is often due to insufficient sunlight or overly fertile soil. These plants prefer full sun and relatively low fertility. Excess nutrients can promote leaf growth at the expense of flowers.

• Common Milkweed – psu.edu

Houseplants

Monstera

Q-Any tips or resources to care for a Monstera plant?
A-Monstera plants thrive in bright, indirect light and should be protected from cold drafts and heating vents. They are tropical understory plants. Allow the top layer of soil to dry slightly between waterings and provide humidity to support healthy growth. Cleaning dust from leaves improves photosynthesis, and staking may be required as plants grow.  It is toxic to humans and pets if ingested.

• Monstera
• Lighting for indoor plants
• Houseplant Care

Using Beneficial Insects for Biological Pest Control

Q-Are beneficial insects recommended for indoor plant pests like thrips, mealybugs, scales and spider mites?
A-Beneficial insects are generally not recommended for houseplants because they are difficult to contain and may disperse throughout the home. Standard treatments such as insecticidal soap or neem oil are typically more practical and effective.

• Houseplant Care – wisc.edu
• Neem Oil – orst.edu
• Insecticidal Soaps – uconn.edu

Insects

Mound Ants

Q-Is there a treatment for mound ants crawling on a cherry tree?
A-Ants are generally not harmful to trees Their presence often indicates sap-feeding insects such as aphids or scale that produce honeydew. Management should focus on controlling those pests rather than the ants. Only in rare cases, such as large ant mounds at the base of plants, might direct intervention be needed. With field ants, the bulk of the colony can often be 2 or 3 feet below ground so you need to take a broom stick, piece of rebar or something like that to poke some channels down into that mound and slowly pour a liquid ant control product a little bit at a time into those channels and let it wick in.  It’s really only necessary if the mound is right there at the base of the tree. One other consideration, and this would be a non-chemical approach, you could consider wrapping the base of the tree with some sort of material on a short-term basis.  This could be something like Saran wrap and then onto that coating put Tanglefoot-a really stick substance. Do not put the Tanglefoot directly on the trunk because it will block oxygen flow there.

• Field Ants – wisc.edu
• Tanglefoot – tanglefoot.com
•  Aphids – wisc.edu

Lily Leaf Beetles

Q-What are the red insects on lilies and how can they be controlled?
A-These insects are lily leaf beetles, an invasive pest that can cause significant damage by feeding on leaves, stems, and buds. Small infestations can be managed by hand removal of adults, larvae, and eggs. The larvae are kind of these ooey-gooey, slug-like looking things. They may look a little bit like bird droppings. You can squish them by hand or knock them into a container of soapy water. Also keep a close eye out for the eggs.  They look like miniature orangish-colored tic-tacs and are usually in a cluster.  Larger infestations may require insecticidal soap, neem oil, or products containing Spinosad, applied carefully to minimize impact on beneficial insects. You would have to spray it on the adults and larvae directly. Once those products dry out, they are essentially done working so you might need to apply multiple times per week.

• Lily Leaf Beetle – wisc.edu
• Insect Lab – Invasive Insects Map – wisc.edu
• Captain Jack’s Deadbug Brew – captainjacks.com

Squash Vine Borer

Q-Is there a way to know when squash vine borers begin and stop laying eggs?
A-Squash vine borer activity typically begins around 900 growing degree days, which often occurs sometime in late June-ish or so in southern Wisconsin. Because this timing varies by weather and location, monitoring both temperatures and adult moth activity is recommended. Adults are distinctive orange-and-black moths active during the day, and there is about a two week window for egg laying. Management strategies include wrapping the base of stems where eggs are laid, using row covers until female flowers require pollination, planting trap crops such as Hubbard squash, adjusting planting timing, and physically removing larvae when detected.

• Squash Vine Borer – wisc.edu
• Growing Degree Days – wisc.edu
• Hubbard Squash – wisc.edu
• Floating row covers – wisc.edu
• Insect Lab – Invasive Insects Map – wisc.edu

Lawns

Rough Bluegrass

Q-How can Poa trivialis (rough bluegrass) be controlled?
A-Poa trivialis thrives in wet, shaded conditions and can be difficult to control. It spreads aggressively and lacks selective control options. It doesn’t like hot weather so it may fade out over the summer. Hand removal and non-selective herbicides are common methods, and improving lawn conditions may help reduce its presence.

• Rough bluegrass – ncsu.edu
• Lawn Maintenance – wisc.edu
• Wisconsin Lawn Care Calendar – wisc.edu
• Lawns – wisc.edu

Violets in Lawn

Q-How can violets be managed in lawns?
A-Violets commonly grow in shaded, moist lawns. Management includes using broadleaf herbicides containing multiple active ingredients, such as triclopyr, improving lawn density, and maintaining proper mowing and fertilization practices. Hand removal can be effective for small areas.

• Violets in lawn – osu.edu
• Lawn Maintenance – wisc.edu
• Wisconsin Lawn Care Calendar – wisc.edu
• Lawns – wisc.edu

Plant Diseases

White Pine Blister Rust

Q-Does White Pine Blister Rust affect Swiss Stone Pines?  How far from white pines does a currant have to be? 
A-White pine blister rust requires both white pines and Ribes species (currants and gooseberries) to complete its life cycle. Avoid planting these hosts close together, ideally maintaining at least 200 feet of separation. Resistant varieties may reduce risk but do not eliminate it. Swiss Stone Pine is in the genus Pinus so it would be affected by white pine blister rust even though it has some resistance.

• White pine blister rust – wisc.edu
• Plant Disease Diagnostic Clinic – wisc.edu

Trees & Shrubs

Dieback on Juniper

Q-What causes scattered dieback on junipers after winter?
A-Scattered dieback in junipers is most often due to winter injury. Contributing factors include desiccation from wind, snow and ice breakage, and rodent feeding such as voles chewing bark under winter cover. Diseases like Phomopsis tip blight typically occur during the growing season rather than winter. Pruning out dead branches in dry weather and observing patterns of damage can help confirm the cause.

• Winter damage concerns for trees – wisc.edu
• Phomopsis tip blight – wisc.edu
• Winter burn – wisc.edu
• Watering in fall – wisc.edu

Chlorosis

Q-A chlorotic witch hazel shrub has not leafed out as well as last year, what is a recommended treatment?
A-Chlorosis is often caused by high soil pH limiting iron availability. A soil test is recommended, and long-term solutions include lowering soil pH and improving soil conditions. Iron supplements may provide temporary relief. Leaf galls are typically caused by insects or mites and are primarily cosmetic, not harmful to plant health.

• Witch Hazel – ncsu.edu
• Soil-testing – wisc.edu
• Chlorosis – wisc.edu
• Deciduous tree galls – wisc.edu

Weeds & Invasive Species

Shamrocks (Oxalis)

Q-How can shamrocks (oxalis, yellow woodsorrel) be controlled in gardens?
A-Oxalis spreads readily by seed and can be persistent. The most effective management is consistent hand removal before plants flower, combined with mulching to reduce seed germination. Long-term persistence will gradually reduce the seed bank.

• Yellow Woodsorrel – wisc.edu

Wildlife

Squirrels stripping bark

Q-Why are squirrels stripping bark from sugar maple trees?
A-Bark stripping on sugar maples is most commonly caused by squirrels feeding on sugar-rich sap in early spring. Emerging research suggests they may also be seeking calcium in the phloem. Extensive damage can girdle trees and reduce their chance of survival. Younger, freshly planted maples can be wrapped in corrugated white plastic to try to protect them.  This issue is not typically caused by disease.

• Squirrels Ecology and Damage Management – wisc.edu

Wildlife Ecology Factsheets

• UW Wildlife Ecology factsheets – wisc.edu