Prepare for winter

By John Fulton

[November 03, 2008]  There is definitely change in the air. The main change heading our way is the temperature going down. We've had a great fall, but all good things have to come to an end. Many of our remaining chores are labeled "final" or have the word "winter" associated with them. Here are some of those chores to be working on, and now we have to add "weather permitting."

Clean up those dead stems and trash. The stems, and trash that collects in them, provide a place for diseases, insects and rodents to live during the winter. If plants were badly infected with diseases, they should be burned or physically moved to another site. All the other vegetation can be added to a compost pile for recycling.

You should also get an inch of water per week on perennial plants, unless Mother Nature does that for us. Do this until the ground freezes. This is one of those rules of thumb that is especially important for evergreens. Evergreens require more water throughout the winter, as they continue to respire through the needles. Evergreens, particularly broadleaved evergreens such as azalea, rhododendron and holly, use more water in cold months. These, and others in locations with drying winds, might even benefit from a windbreak or a spray treatment with an anti-desiccant.

Winter mulches should be put on after the ground actually begins to freeze. Thanksgiving time is a good average guess for timing. Winter mulches put on too early might delay the natural dormancy process. Mulches should be 2 to 4 inches deep, and the ground should be moist before applying them.

Tender bulbs, roots or corms should be dug, if you already haven't done so. These would include dahlia, canna, caladium, tuberous begonia and gladiolus. Many of these will actually have rotting problems from frost. Be careful when digging so the bulbs are not cut, as any wound usually means a rot will begin. Any bulbs that look diseased should be thrown away. Most can be dried at room temperature, but gladiolus should be dried at a higher temperature (70-80 degrees) and dusted with malathion to protect against thrips. Store all the bulbs in a cool, dry place.

This is not a very good time to prune anything. We need to let the plants go through the dormancy process, which should be completed by late November. Pruning at this time could promote new growth, delay the dormancy process and attract beetles that carry diseases.

Recommended pruning times begin in December for high-sap-flow trees, such as maples and sweet gums. Most trees should be pruned in late February or early March, before sap begins to rise again. Flowering trees and shrubs should be pruned after they flower, assuming you want the blooms for the year. Otherwise, they could be pruned in the February-to-March period. Evergreens, including broadleaf evergreens, are best pruned in late June.

Definitely wait to prune oak trees until December, as the beetles that transmit oak wilt virus are attracted to pheromones given off in sap that might escape with earlier pruning. The other disclaimer is for ash trees. Our traditional ash borer, which we have had around for many years, is a weak borer that often enters through pruning cuts. Many experts recommend not pruning ash trees until they are at least 8 years old.

Good weather and bad weather will be interspersed for the next few weeks -- at least we hope there is some good weather in there! Take advantage of the good days to finish up those outside chores.

[By JOHN FULTON, University of Illinois Extension, Logan County]