AYGQ: LIVE – January 2026 Session Links and Resources

Fruits & Vegetables

Grapes

Q-I have one grape vine that had some kind of fungus on one branch. I trimmed that well back, but the vine has not thrived. Can anything be done or should I cut my losses and replace it?

A-Depending on the disease, you may be able to select a strong new cane this spring and retrain it as a replacement cordon.  If regrowth remains weak, replacement may be the best option.  Consider submitting a sample to the Plant Disease Diagnostic Clinic (PDDC) for diagnosis. (Josie Dillon)

• Plant Disease Diagnostic Clinic (PDDC): https://pddc.wisc.edu/sample-submission/
• Grape Disease Management: https://fruit.webhosting.cals.wisc.edu/wp-content/uploads/sites/36/2016/03/DiseaseMgmtVolenberg.pdf

Grapes

Q-What shrubs/trees can block herbicide drift to protect grapes?

A-Dense conifers (cedars, pines) provide the most effective physical windbreak, but all plants can be injured by drift.  Grapes are especially sensitive and even minute drift levels can cause injury.  If drift damage occurs, contact the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP). (Josie Dillon, Tim Ripp, Vijai Pandian)

• DATCP Pesticide Complaints: https://datcp.wi.gov/Pages/Programs_Services/PesticideComplaints.aspx

Raspberries

Q-Raspberries are producing poorly—what should be done?

A-Production depends on whether plants are: Summer-bearing → fruit on second‑year canes; Fall-bearing → fruit on first‑year canes.  Correct pruning helps restore vigor.  Old raspberry patches (15–20+ years) naturally decline—consider replanting or relocating.  Winter injury and root diseases also reduce production. (Josie Dillon, Bruce Spangenberg)

• Growing Raspberries in Wisconsin: https://hort.extension.wisc.edu/articles/growing-raspberries-wisconsin/
• Growing Raspberries in the Home Garden-Pruning: https://extension.umn.edu/fruit/growing-raspberries-home-garden#pruning-697661

General Gardening

Dahlias

Q-What if overwintered tubers sprout too early?  How to “wake” them up in spring?

A-Early sprouting usually means storage is too warm or exposed to light. Keep dahlias in a cool (not cold) area, away from windows, slightly moist but never wet.  Plant outdoors in mid to late May.  Potting up in April is fine if desired. (Vijai Pandian)

• Storing Tender Bulbs for the Winter: https://hort.extension.wisc.edu/articles/storing-tender-bulbs-for-winter/
• Starting Dahlias Indoors: https://yardandgarden.extension.iastate.edu/faq/when-should-i-start-dahlias-indoors

Geraniums

• https://hort.extension.wisc.edu/2024/09/26/overwintering-tender-geraniums/

Mulch

Q-What to do with an over‑accumulation of mulch? Can it be worked into soil?

A-Excess mulch (e.g., >6 inches) may cause: water infiltration issues; reduced oxygen exchange; matting that repels rainfall.

Perennial beds: Do not till deeply—risk of damaging roots.  Remove excess mulch if overly thick.

Vegetable beds: You may incorporate organic mulch but monitor nitrogen levels as decomposition temporarily ties up nitrogen.  Best mulches for perennial gardens: Leaf mulch, Compost.  Avoid heavy use of wood chips directly around herbaceous perennials. (Amy Freidig, Tim Ripp, Vijai Pandian)

• Mulch for home and garden plantings: https://hort.extension.wisc.edu/articles/mulches-home-gardens-and-plantings/
• Mulching trees and shrubs: https://hort.extension.wisc.edu/articles/mulching-trees-and-shrubs/
• Making and Using Compost in the Garden: https://hort.extension.wisc.edu/articles/making-and-using-compost-in-the-garden/
• Leave the Leaves?: https://hort.extension.wisc.edu/2023/09/08/leave-the-leaves-to-rake-or-not-to-rake/

Perennial Plant Transplanting

Q-Moving Perennial plants from one home to another-best time and process?

A-Best timing:  Move spring/summer bloomers in fall; move fall bloomers in spring.  Keep plants in the ground as long as possible as pots may stress root systems.  Prepare beds at the new location before transplanting.

Important caution: Moving plants may also transport pests such as jumping worms or lily leaf beetles. If your garden has these pests, starting fresh may be safer. (Amy Freidig, Tim Ripp, PJ Liesch)

• How to divide and transplant perennials: https://yardandgarden.extension.iastate.edu/how-to/how-divide-and-transplant-perennials
• Jumping Worms: https://hort.extension.wisc.edu/articles/jumping-worms/
• Lily Leaf Beetle: https://hort.extension.wisc.edu/articles/lily-leaf-beetle/

Seed Starting

Q-Is it too early to start flower and vegetable seeds indoors?

A-Yes, it’s a bit early to start vegetable seeds indoors. Cool season crops like kale and broccoli can be started by mid to late March, so it’s ready for planting outdoors in early May. (Vijai Pandian)

• The Vegetable Garden: https://hort.extension.wisc.edu/articles/vegetable-garden/
• Seed Starting: https://hort.extension.wisc.edu/articles/seed-starting/
• Damping-Off: Tips on Seed Starting to Avoid Disease: https://hort.extension.wisc.edu/2021/03/05/dampening-damping-off-tips-on-seed-starting-to-avoid-disease/
• Soil Temperature guide: https://kenosha.extension.wisc.edu/files/2021/03/Soil-Temp-Planting-V2docx.pdf

Seed Starting-Winter Sowing

Q-What are the basics of winter sowing? Does it work in Wisconsin?

A-Yes, winter sowing works well, especially for native perennials that require cold stratification.

Process: Use a milk jug or similar container; fill bottom with potting mix; Sprinkle seeds; add a light soil layer. Place outdoors in February.  Freeze–thaw cycles break dormancy; seeds sprout when conditions are right. (Vijai Pandian)

• Winter Sowing: https://extension.missouri.edu/publications/ym105

Soil

Q-Soil seems “lifeless.” How to improve it?

A-Incorporate organic matter: compost, shredded leaves, or well‑rotted manure.  Avoid adding diseased leaves—many pathogens overwinter in leaf litter. (Bruce Spangenberg)

• Using Manure in the Home Garden: https://hort.extension.wisc.edu/articles/using-manure-in-the-home-garden/
• Making and Using Compost in the Garden: https://hort.extension.wisc.edu/articles/making-and-using-compost-in-the-garden/
• Soil Contaminants in Community Gardens: https://hort.extension.wisc.edu/articles/soil-contaminants-community-gardens/
• Soil—Making and Using Compost in the Garden: https://hort.extension.wisc.edu/articles/making-and-using-compost-in-the-garden/
• Soil—Using Wood Ash in the Home Garden: https://hort.extension.wisc.edu/articles/using-wood-ash-in-the-home-garden/

Houseplants

Arrowhead plant (Syngonium)

Q-Leaves are curling in a north-facing window, why?

A-Likely environmental stress: cold drafts near windows, dry furnace air, low light. North-facing windows in Wisconsin offer minimal winter light. Consider moving the plant to warmer conditions and/or using grow lights. If concerned, submit photos via “Ask Your Gardening Question.” (Amy Freidig & Panel Members)

• Ask Your Gardening Question Form: https://hort.extension.wisc.edu/ask-a-gardening-question/
• Syngonium podophyllum: https://plants.ces.ncsu.edu/plants/syngonium-podophyllum/
• Houseplant Care: https://hort.extension.wisc.edu/articles/houseplant-care/

Water Lily

Q-The water lily’s water is green.  Should it be drained and replaced?

A-Placing the container in full sun encourages algae growth causing the container and water to turn green. It’s best to place the container where it receives a mix of sun and shade to slow down the algae growth. You can also add more lilies or other water plants to block algae growth in the container.  (Vijai Pandian)

Insects

Imported Cabbageworms

Q-How to prevent cabbage worms on kale? Are some kale varieties resistant?

A– No kale variety is reliably resistant.  Best management strategies: Floating row covers to prevent egg-laying. Hand-picking if garden is small.  Chemical:  Bacillus thuringiensis var Kurstaki or Aisawai applied to early instar larvae can be very effective in controlling imported cabbageworms. Start early in the season for best results. (PJ Liesch)

• Imported Cabbageworm:  https://hort.extension.wisc.edu/articles/imported-cabbageworm/
• Floating Row Cover: https://hort.extension.wisc.edu/articles/floating-row-cover/
• Home Vegetable Insecticides: https://hort.extension.wisc.edu/articles/home-vegetable-insecticides/

Japanese Beetles

Q-How can Japanese Beetles be managed without harming pollinators?

A-Management varies depending on whether the issue is grubs in lawn or adult beetles on plants.

Adult management: Early‑season hand-picking prevents aggregation. Floating row covers for non‑pollinated crops.  Btg – Bacillus thuringiensis subsp. galleriae (the active ingredient in beetleGONE!)—organic option but must be purchased online.  Azadirachtin, another organic ingredient, also has low environmental impacts and can be used on landscape plants, vegetables and berry crops.  However, these products should be applied in late evening after pollinator activity subsides to minimize risks.  Insecticidal soaps and horticultural oils (such as neem oil) have very limited effectiveness against Japanese beetles. Conventional insecticides work but must be used carefully to avoid pollinator exposure. 

Grub management is separate from adult feeding. (PJ Liesch)

• Japanese Beetles: https://hort.extension.wisc.edu/articles/japanese-beetle/
• White Grub Control in Turfgrass: https://hort.extension.wisc.edu/articles/grub-control-home-lawn/

Sawflies

• https://hort.extension.wisc.edu/articles/sawflies/

Spider Mites

• https://hort.extension.wisc.edu/articles/twospotted-spider-mite-tetranychus-urticae/

Whiteflies

Q-How to manage whiteflies on herbs, potted plants and patio plants?

A-Whiteflies in Wisconsin are more common on indoor plants, greenhouse plants, or late‑season tomatoes/peppers. Start with clean plants—inspect nursery material carefully. Consider starting vegetables from seed to avoid importing pests.

Tools for management: Yellow or blue sticky traps to monitor and reduce adults.  Insecticidal soaps or horticultural oils but remember they work only on contact and require repeated treatments. Maintain regular scouting and rotate traps to track population trends. (PJ Liesch)

• Whiteflies: https://hort.extension.wisc.edu/articles/whiteflies/

Lawns

There were no questions on lawns this month.

Plant Diseases

Peach Leaf Curl

• https://hort.extension.wisc.edu/articles/peach-leaf-curl/

Trees & Shrubs

Oak Tree Pruning

Q-When is it safe to prune oak trees to avoid oak wilt?

A-Prune oaks during dormancy and no later than April 15.  Never prune in June or July—risk of oak wilt is highest.  If storm damage occurs during high‑risk months, make a clean corrective cut.  Immediately apply wound dressing to prevent sap beetles from transmitting oak wilt.  For significant tree damage, contact a certified arborist. (Bruce Spangenberg, Tim Ripp, Vijai Pandian)

• Oak Wilt: https://pddc.wisc.edu/2019/08/06/oak-wilt/
• Pruning Deciduous Trees: https://hort.extension.wisc.edu/articles/pruning-deciduous-trees/
• Find a Certified Arborist: https://www.isa-arbor.com/Find-an-Arborist

Pruning Roses

• https://extension.illinois.edu/roses/pruning

Snowberry Shrub

• https://plants.ces.ncsu.edu/plants/symphoricarpos-albus/

Weeds & Invasive Species

Bindweed

• https://extension.psu.edu/the-noxious-persistent-invasive-and-perennial-bindweeds

Bishops Weed, Bishop’s Goutweed, Snow on the Mountain

Q-How to control this weed from taking over a native plant bed?

A-This plant spreads aggressively through underground rhizomes.  Control is multi‑year: Persistent hand‑pulling every ~3 weeks gradually reduces root reserves.  Mulch can help but will not eliminate it. Smothering (cardboard, tarp, plastic) may require 6–24 months and may still fail. Digging out soil is an option but requires removing 6–12 inches and sifting thoroughly to remove rhizomes. Non‑selective herbicides (glyphosate) can work but require repeated applications and extreme caution around non‑target plants. (Amy Freidig, Bruce Spangenberg, Vijai Pandian)

• Bishops Goutweed: https://dnr.wisconsin.gov/topic/Invasives/fact/BishopsGoutweed
• Video of weed management for Bishop’s Goutweed (starts at minute 15:03) – https://hort.extension.wisc.edu/articles/management-of-perennial-weeds/
• Mulches for Home Gardens and Plantings: https://hort.extension.wisc.edu/articles/mulches-home-gardens-and-plantings/

Buckthorn

Q-What are the best practices for removing large buckthorn?

A-Develop a 4–5‑year management plan—buckthorn problems are rarely solved in one season.  Start with removing mature trees (>6” diameter) to reduce seed production.  Late fall is the optimal time for control.  After cutting at the base, paint the stump with a concentrated brush killer (typically triclopyr, sometimes with glyphosate).  If cut during the growing season, expect resprouting, which can be treated with a foliar application. Important: If the tree has fruit, rake up fallen berries after cutting to prevent new seedlings. (Vijai Pandian)

• Buckthorn: https://hort.extension.wisc.edu/articles/common-buckthorn/
• Critical Period Cutting Method: https://fmr.org/updates/conservation/how-and-when-use-critical-period-cutting-method-remove-invasive-buckthorn
• Chemical Free Buckthorn Removal: https://www.buckthornbaggie.com/

Thistles

• https://renzweedscience.cals.wisc.edu/invasiveplantid/thistles/

Weed Control

• https://hort.extension.wisc.edu/article-topic/weed-control/
• Weed Control-Alternatives to Glyphosate: https://content.ces.ncsu.edu/are-there-alternatives-to-glyphosate-for-weed-control-in-landscapes
• Weed Identification: https://hort.extension.wisc.edu/article-topic/weed-identification/

Wildlife

Deer Control

Q-What strategies actually work?

A-Only foolproof solution: fencing (physical barriers). Repellents work inconsistently and wash off easily.  Motion‑activated sprinklers sometimes help. Native shrubs often tolerate browsing better.  PlantSkydd is an effective repellent but should be used only on non‑edible plants. (Bruce Spangenberg, PJ Liesch, Tim Ripp, Vijai Pandian)

• Controlling Deer Damage in Wisconsin: https://hort.extension.wisc.edu/articles/controlling-deer-damage-wisconsin/
• Plants not Favored by Deer: https://hort.extension.wisc.edu/articles/plants-not-favored-deer/

Rabbit Ecology and Damage Management

• https://hort.extension.wisc.edu/articles/protecting-gardens-and-landscape-plantings-rabbits/

UW Wildlife Ecology factsheets

• https://wildlifedamage.cals.wisc.edu/