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- Giving Thanks for Gardening
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- Be on the lookout for new uninvited house guest.
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- Little bulbs yield major reward in spring
- Trial Plants winners for 2016
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- Saving Seeds from Favorite Garden Plants
- View Full Archive >>
The Homeowners Column
Spring landscape activities
Extension Educator, Horticulture
The seasons wax and wane. We experience rakes and rain. Spring is almost here according to the calendar but the weather has us on a temperature roller coaster ride. Rising warm spring temperatures fuel our sense of omnipotence in our gardens. 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 will probably plant them the first nice day in April, but hey, I tried to warn you).
- Finish pruning apples and grape vines.
- Plant hardy vegetables such as kale, leaf lettuce, potatoes, spinach, and turnips.
- Prune trees and summer flowering shrubs while still dormant. Many shrubs can be reduced in size by using renewal or heading back methods. Sterilize tools in between each cut with 10% bleach when pruning diseased plants. Summer flowering shrubs bloom on new wood after mid June. Renewal pruning method is the removal of the oldest stems leaving the younger stems to develop.
- Wait to prune early flowering forsythia and lilac until after flowering.
- If needed, rejuvenate shrubs such as Anthony Waterer spirea, honeysuckle, 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.
- Inspect trees with a past history of tent caterpillar. Look for dark brown or gray egg masses that encircle the twig. Destroy by pruning or scratching off with thumbnail.
- Apply dormant oil spray to euonymus to control the insect euonymus scale. Dormant oil sprays will 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. The cool season grasses such a Feather Reed Grass (Calamagrostis x acutiflora) green up quickly in spring so don't wait. The popular Miscanthus cultivars are warm season grasses so a little more time is available to prune them.
- 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.