AYGQ: LIVE – June 2026 Session Links and Resources

Fruits & Vegetables

Asparagus

Q-Why did a mature asparagus bed produce poorly this year? 
A-Reduced yields may result from overharvesting in previous years, which can weaken plants. Other contributing factors include weed competition, nutrient deficiencies, poor soil drainage, or disease. Proper harvesting duration and soil fertility management are key to maintaining productivity. 

• Growing asparagus – umn.edu
• Soil testing – wisc.edu

Apples

Q-Should Honeycrisp apples be thinned, and how? 
A-Fruit trees often set more fruit than they can support. Thinning clusters down to one to two fruit per cluster improves fruit size and reduces stress on the tree. Small fruitlets can be removed by hand at the cluster, helping the remaining fruit develop more fully.

• Growing Apples in Wisconsin – wisc.edu

Q-Can you pluck the suckers off your apple and pear trees at this time of year? 
A-Yes! You can simply pull them up or cut them back to the ground or the trunk. Now is a great time to remove these. 

• Training and pruning apple trees – wisc.edu

Grafting

Q-Can rootstock be dug up now for whip-and-tongue grafting? 
A-Grafting is best done in late winter or early spring while scion wood remains dormant. Attempting grafting during active growing conditions increases disease risk and reduces success. Waiting until the appropriate season improves graft union formation. 

• Whip and tongue grafting apple trees – iastate.edu
• Rootstocks for fruit trees in Wisconsin – wisc.edu

Cauliflower

Q-Why are cauliflower plants producing leaves but no heads? 
A-Cauliflower is sensitive to stress, especially heat and inconsistent growing conditions. Stress can prevent head formation. Planting earlier in cooler conditions or growing as a fall crop often improves success.

• Growing cauliflower – wisc.edu
• Cool and warm season crops – wisc.edu

Grapes

Q-Why do grapevines produce excessive foliage but only a few fruit clusters? 
A-Excessive vegetative growth can result from favorable weather conditions. Light pruning to improve airflow and sunlight penetration around clusters helps reduce disease risk and supports fruit development.

• Growing grapes in Wisconsin – wisc.edu

Fertilizing Fruit Trees

Q-Can peach or apple trees be fertilized later in the season? 
A-Fertilization is best done in early spring. Late applications can promote excessive vegetative growth and increase disease susceptibility. Soil testing is recommended to guide nutrient applications. 

• Soil testing – wisc.edu
• Growing peaches in Wisconsin – wisc.edu
• Growing apples in Wisconsin – wisc.edu

Plums

Q-Will a plum tree recover after frost damage reduced leaves and fruit? 
A-Late spring frost can damage blossoms and reduce fruit set, while winter injury may impact overall plant health. Trees often recover, but extent depends on severity of damage. (Josie Dillon, Bruce Spangenberg) 

• Growing plums in Wisconsin 

Sour Cherry

Q-What caused sour cherries to shrivel and crack? 
A-Symptoms suggest a possible fungal disease such as brown rot rather than environmental stress. Submitting samples to the Plant Disease Diagnostics Clinic can confirm diagnosis. (Josie Dillon) 

• Brown rot 
• Plant Disease Diagnostic Clinic 

Seedling Damage

Q-What causes seedlings like tomatoes and peppers to be cut off at the base, and how can it be managed? 
A-Cutworms are likely responsible for severing young plants near soil level. Preventative strategies include placing collars around transplants and monitoring early in the season. Insecticides are most effective when applied before damage occurs, but physical barriers are often the most practical solution.

• Cutworms – wisc.edu
• Degree days for common insect pests – wisc.edu
• General approaches to insect control – wisc.edu

General Gardening

Columbine

Q-Why is a columbine patch declining and not reseeding well? 
A-Columbine plants may naturally decline as they age. Seed dormancy and delayed germination can also affect reseeding success. Pest damage and environmental stress may contribute. Fall seeding or supplementing with nursery plants can help reestablish the patch. 

• Columbine – iastate.edu
• Common columbine pests – wisc.edu

Groundcover Recommendations

Q-What are good groundcovers between pavers? 
A-Low-growing, durable plants such as creeping thyme, ajuga, sedum, and certain veronicas work well. Selection depends on sunlight, moisture, and foot traffic. Fragrant species like thyme can enhance the sensory experience. 

• Groundcovers – wisc.edu
• Lemon thyme – wisc.edu
• Ajuga – ncsu.edu
• Sedum – missouri.edu
• Ground cover veronicas – wisc.edu
• Creeping thyme – ncsu.edu

Transplanting Perennials

Q-Can small perennial seedlings be transplanted outdoors? 
A-Seedlings approximately two inches tall can be transplanted if properly hardened off. Careful watering and protection from heat stress are essential during establishment. 

• Hardening indoor seedlings – illinois.edu

Houseplants

There were no questions on houseplants this month.

Insects

Ants in Compost

Q-Are ants in compost a concern and can the compost still be used? 
A-Ants are often attracted to food scraps and may nest in compost. Their presence typically does not make compost unusable. Managing inputs and disturbing nests can reduce activity. If you are concerned, don’t use it on your vegetables.

• Making and using compost in the garden – wisc.edu

Butterfly bush damage

Q-What should be done when insects are eating butterfly bush leaves? 
A-Proper identification of the pest is essential before treatment. Integrated Pest Management (IPM) emphasizes monitoring, tolerance thresholds, and minimal chemical use. Physical removal or targeted treatment may be sufficient once the pest is identified.

• Integrated Pest Management – cornell.edu
• General approaches to insect control – wisc.edu
• UW Insect Diagnostic Lab – wisc.edu

Lily Leaf Beetle

Q-How should lily leaf beetles be managed? 
A-Lily leaf beetles can severely damage true lilies. Hand removal of eggs and larvae is effective for small infestations. Organic insecticides such as Spinosad or neem oil may be used when larvae are young. 

• Lily leaf beetle – wisc.edu

Lawns

Bumpy Lawn

Q-How can a bumpy lawn be improved after aeration? 
A-Repeated aeration combined with topdressing using quality soil helps smooth uneven surfaces over time. Improving soil structure gradually leads to better turf conditions. 

• Lawn aeration and topdressing – wisc.edu

Plant Diseases

There were no questions on plant disease this month.

Trees & Shrubs

Forsythia

Q-Why did forsythia fail to bloom this year despite appearing healthy? 
A-Lack of bloom is most often due to weather-related stress such as late spring frosts damaging flower buds. Additional factors may include excessive shade or improper pruning timing. Forsythia should be pruned immediately after flowering to preserve next year’s blooms. 

• Forsythia – wisc.edu
• Pruning deciduous shrubs – wisc.edu

Lilac

Q-What is the best way to propagate lilacs? 
A-Lilacs are most easily propagated by digging and transplanting root suckers. Stem cuttings are also possible but require controlled humidity and rooting hormone for success. 

• Home Propagation of Garden and Landscape Plants – missouri.edu
• Lilacs for cold climates – wisc.edu

Q-My lilac has bloomed. Is it time to cut it back? How should it be cut back? 
A-You can prune right after flowering, or during the dormant season. Dormant season pruning allows you to see the architecture of the plant and insects and disease pressure is absent. However, you will be pruning off the upcoming year’s flowers. When pruning, remove about 1/3 of the largest diameter branches back to the base of the plant every few years for the larger, common lilacs. Do not do this for dwarf lilacs like ‘Palibin’ or ‘Bloomerang’. Never shear lilacs as you are removing flower buds which are set in the summer for the following spring bloom. 

• Pruning deciduous shrubs – wisc.edu
• Proper timing key when pruning – wisc.edu

Serviceberry

Q-Is Autumn Brilliance serviceberry hardy for Wisconsin, and how far from a building should it be planted? 
A-Serviceberry is a hardy native small tree suitable for Wisconsin. It typically grows around 25 feet tall with a spread near 15 feet. Planting approximately 20 feet from a structure allows adequate space for growth, airflow, and root expansion. 

• Serviceberry – wisc.edu
• Proper tree planting – wisc.edu

Q-An Autumn Brilliance serviceberry was planted a few years ago in the fall. It bloomed beautifully in the spring and then didn’t get leaves and died. Any idea what might have happened? It’s near a Black Walnut; would that be a problem? 
A-It’s always good to be aware of the black walnuts because they do affect lots of different kinds of plants.  Damage to the trunk and susceptibility to both sun scald and frost cracks could be a cause. Voles or other environmental factors are also considerations. 

• Black walnut toxicity – wisc.edu

Weeds & Invasive Species

Corn Gluten as Weed Suppresent

Q-When should corn gluten be applied to prevent germination of fall emerging weeds? 
A-Corn gluten meal is a natural material that does have pre-emergent activity, but it also has a lot of nitrogen in it.  Typically, it’s used in the spring for crabgrass control in lawns. It normally takes several years to build it up to get to the point that it gives you satisfactory control compared to synthetic options. It’s applied around Labor Day for chickweed and some winter annuals. It’s expensive and the rate to apply per thousand square feet exceeds nitrogen recommendations. 

• Corn gluten meal – wisc.edu

Wildlife

Wildlife Ecology Factsheets

• UW Wildlife Ecology factsheets – wisc.edu