and click on the Good Gardening link under News & Updates. It is also on the Lake County Webpage, lake.extension.uiuc.edu (no www needed). Other counties also feature it on their county webpage. Contact your local office to find out if they have it posted on their webpage.
Thanks for asking. I will be looking at all the comments returned on the survey, so you may see some changes to the newsletter this year.
Weird Winter
This winter has been unusual. First a large snowfall in early December, then hardly a day to get the winter coat out of the closet until mid-January. During that really warm spell, you may have noticed some of your flowers trying to sprout and maybe even the buds on some of your trees and shrubs starting to swell.
Should we be worried? Not yet. Since the cold weather has returned, the plants have slowed their development. However, if we should get another warm spell, the plants might get growing too early and then we could see some damage.
Our perennials and spring bulbs may try to make an early appearance if the weather warms. If only foliage is showing, the damage would be to the leaves only and our spring bulbs could go ahead and bloom normally. Remember that spring bulbs will bloom in cool weather, so they are a little tougher than other plants. Perennials that start to leaf out may see leaf damage, but they will re-grow from their roots. They will be stressed, but most will not die.
Buds on some trees and shrubs began to swell in the warm spell. Another warm spell could cause them to open early, which could lead to loss of flowers, leaves and even some small stems. Again, the plants will not die, but the damage here could be slightly more than on our perennials. Trees and shrubs that flower early would be most at risk.
Garden Tidbit:Plants to prune now: -deciduous trees (except -maples, elms and birches; they are bleeders) -shrubs that bloom in late summer or fall
Plants to prune later: -evergreens (pruning of these plants usually coincides with new growth) -shrubs that flower in spring (prune them within two weeks after they finish flowering)
A Few "To-do" items for Feb-March
February:
order garden seeds now to ensure that you get the varieties you want
try starting geraniums from seed; it takes 12-16 weeks to go from seed to flower, so start now
plan a new garden now
March:
cut back ornamental grasses
finish your garden cleanup
some cool season vegetables can be planted in mid-April, start seeds now
start summer bulbs inside in late March for planting outside after frost
Black Knot Disease
Black knot is caused by a fungus. It commonly affects plums, prunes and cherries (which are all members of the genus Prunus). Other species of Prunus, such as apricot, peach and flowering almond are rarely damaged.
Symptoms of black knot are usually found on twigs, branches and fruit spurs. It is possible for trunks to become infected as well. Infections generally begin on young tissue.
Twigs are infected in early spring, but may not show symptoms until autumn. In autumn, twigs show small, light brown swellings that will enlarge and rupture the following spring. The enlarging knots have a corky texture and are covered with a green fungal growth. The knots enlarge and darken during the summer, and by autumn they are hard, rough and completely black.
If the knot completely girdles the stem, the stem will die. Larger branches may live for years before being killed by a perennial, ever-enlarging knot. Heavy infestations can cause the tree to lose vigor and in time may kill the tree. In old knots, the fungus will die and the knot may be invaded by secondary fungi. These old knots may take on a white or pinkish color due to this secondary invasion.
Most black knot infections occur during bloom or within two weeks after bloom. As is common with fungal diseases, weather is a critical factor. Wet conditions, occurring when temperatures are between 55 and 77 degrees F, are necessary for the fungal spores to infect the plants. Infections will occur until the terminal growth of the plant stops or until the supply of spores is exhausted. Fungal spores are spread by splashing rain and by wind.
Non-Chemical Controls:
When buying new plants, avoid any tree that has visible knots or swellings on branches.
Prune out and destroy infected branches in late winter or early spring . Make the cut 4-8 inches below the knot or swelling.
If possible, destroy any nearby wild plum and cherry trees.
There are fungicides that can be applied. They should be used more than once: during dormancy, when flower buds show color, at petal fall and 3 weeks later.
Check with your local Extension office for current recommendations. Recommended pesticide may vary depending on the use of the tree (for fruit or for ornamental appeal)
Ornamental Grasses- Cut Back in Spring
Ornamental grasses need to be cut back in spring to allow new growth to come in. In northern Illinois, we are usually doing this in March. Cool season grasses should be looked at first, since they begin growing first. They often come through winter fairly green and may not need to be cut back.
Warm season grasses will start growing a little later, but March is still the normal time frame for cutting them back. The cutting should be done before new growth starts. Otherwise the new growth may be cut away with the old.
Old growth should be removed as closely to the ground as possible. All the new growth will come from the root system.
Wait on Lawn Care
There is still snow on the ground now, but as soon as it melts, many homeowners will start to think about lawn care. It is common to see people putting fertilizer and crabgrass control down way before spring arrives.
It is best to wait until the right time arrives. We really should not do much to lawns until at least April. Crabgrass will not germinate until the SOIL temperature is above 55 degrees for 5-7 consecutive days. That normally does not happen until late April or early May. To apply a crabgrass preventer now, would be a waste of time and product. Just because it is being sold in the store, does not mean it is time to apply it.
Lawn fertilizers are often applied too early as well. Wait until May to put on the first application of fertilizer. At that time the plants will be able to utilize the fertilizer and will be able to take it up from the soil.
