- Plants in holiday traditions
- Can houseplants improve indoor air quality?
- Cautious garden banter
- Giving Thanks for Gardening
- Food for thought – Insects on the menu
- Be on the lookout for new uninvited house guest.
- Holes in trees – wood borer or woodpecker?
- Little bulbs yield major reward in spring
- Trial Plants winners for 2016
- Yellowjackets – insects with attitude
- View Full Archive >>
The Homeowners Column
Grab your pruners and your trowel; time for spring gardening
Extension Educator, Horticulture
The seasons wax and wane as we rake and strain. Rising spring temperatures fuel our sense of garden omnipotence; then a cold wave slaps us back into the reality of spring weather.
Rolling temperatures bring questions about when to do what. So get out your red pen and start checking.
Average last frost date is approximately April 21. For tender plants such as impatiens, coleus, canna, basil, and tomatoes, wait until after May 10 before planting. (You'll probably plant them the first nice day in April, but hey I tried to warn you).
- Finish pruning apples and grape vines. Sterilize tools in between each cut with kitchen or bathroom disinfecting spray when pruning diseased plants.
- Peaches should be sprayed now with lime sulfur if peach leaf curl has been a problem.
- Plant hardy vegetables such as kale, leaf lettuce, potatoes, spinach, and turnips.
- Prune trees and summer flowering shrubs. Many shrubs can be reduced in size by using renewal method (removal of the oldest stems leaving the younger stems to develop) or heading back method. Summer flowering shrubs bloom after mid June on new wood.
- Wait to prune early flowering viburnum, forsythia and lilac until after flowering.
- Rejuvenate shrubs such as redtwig dogwood and privet by cutting stems down to 4 to 6 inches.
- Transplant or plant trees and shrubs. Plants preferring spring transplant over fall include most oak, birch, baldcypress, dogwood, and magnolia.
- Scout for bagworm bags on evergreens especially spruce, juniper, and arborvitae. Bagworms often start in the tops of trees so remember to look up. Remove and destroy bags now. Each bag could produce hundreds of caterpillars. Sprays are ineffective until mid to late June.
- Apply systemic imidacloprid insecticide to susceptible high profile plants such as linden trees and roses for control of Japanese beetles. Read and follow all label directions.
- Apply dormant oil spray to euonymus to control euonymus scale. Dormant oil sprays also give partial control of pine needle scale. Temperatures should be above freezing for 24 hours after spraying.
- Some scale species such as oystershell scale are not controlled by dormant oil sprays. Get accurate identification of insect to determine control program.
- Clean up any plant debris that wasn't removed last fall. Gradually pull back mulch from plant crowns.
- Cut back ornamental grasses to 4-6 inches before growth starts.
- Late March – early April gradually pull back mulch from roses.
- Be on the look out for rabbit damage on newly emerging perennials and spring bulbs. Fencing or inverted wire mesh baskets provide the only complete protection. Repellants may give some control.
- Wait until broadleaf weeds are actively growing before treating with postemergence herbicides.
- Get lawn mower ready. Sharpen blades, change oil and clean air filter.
- Wait until late April to early May for first fertilizer application.
- Rake up any twigs and debris.
- Wait until April to apply crabgrass control otherwise a second application may be necessary to control late season crabgrass seed germination.
- Establish lawns by sod throughout season as long as adequate water is available.
- Establish or renovate turf by seed. Prepare soil properly and get good seed to soil contact. Select turf mixes and blends appropriate to the site and to maintenance practices. Southern Illinois – March; Central Illinois – March15-April 15; Northern Illinois – April.