Winter is just around the corner even though there is still good color left in the cottonwoods, aspens, sumac, maples and ash trees. So enjoy it while you can but don't put away your gardening tools just yet.
Here is a list of possible gardening chores you may need to do in preparation for winter and during the winter.
Don't forget that we live in a fairly dry area with low humidity so while leaves are leaving your trees, shrubs and woody perennials, they still will need a drink or two to make it to next spring in good shape. We have had exceptional rainfall this year, with my rain gauge recording over 11 inches thus far — double my normal amount.
Most of us will be able to get by with one or two irrigations until next April. If you are on ditch water make sure you get one last watering done before they shut it off. I certainly try to get a watering completed in November. I will also attempt a late winter, early spring watering if at all possible. My plants make it through the winter in much better shape if I follow this advice. Evergreens are especially vulnerable to winter desiccation.
Mulching is a very good way to prolong the time between watering plants but don't pile on a lot more mulch until after a few hard freezes and the ground starts "toughening up." And be careful about using fallen leaves as mulch. Often times these leaves harbor disease organisms that will initiate next year's disease problem. It would be better to rake these leaves up and either dispose of them or put them in your compost pile where natural heating should kill these disease organisms. Cottonwood and aspen leaves are notorious as carriers of disease pathogens.
Pruning is permissible after trees and shrubs shed their leaves and go dormant but I usually wait until spring to prune back shrubs and woody perennials as they often provide some winter interest if left alone.
Another chore that often goes undone is the application of products containing imidacloprid for various insect pests. This is a systemic material I apply as a soil drench in the fall for control of poplar twiggall fly in my aspens. This product is easy to use, safe to us, and lasts 12 months. So even though this pest does not appear until next spring, this fall application is still working. I don't know about you but I get really busy as spring arrives and I have been known to miss the timing of this application.
Imidacloprid will also control many kinds of aphids, black vine weevils, many wood-boring beetles, leafminers, soft scales, sawfly larvae, elm leaf beetles, lacebugs and even eryophid mites in cottonwoods.
We had an outbreak of blotch leafminers in cottonwoods this year that made their leaves look pretty bad. Many people became aware of these tiny moth larvae when they left their leaf mines and dangled down from their trees by long silken threads. Many calls were received by yours truly. I had not seen this level of activity in the 6-1/2 years I have lived here nor could I find anyone with a longer tenure that remembered problems with this pest.
Hopefully this is a once-in-a-lifetime event. I bring this pest up because while my many narrowleaf cottonwoods were heavily infested, my imidacloprid-treated aspens were clean. I do not advocate treating for this pest unless we have a repeat performance next year. Multiple yearly infestations can decrease the health of trees but one year, no big deal.
This will be my last bi-weekly column until next April. But I will consider writing up to one column a month if there is something worth discussing and the mood strikes me. Until then, enjoy what remains of fall color and start planning next year's garden. But first, make sure you have winterized your garden.
Jim Leser retired to Cedaredge after a career with Texas A&M University Extension in entomology. He is a member of the Cedaredge Tree Board and a master gardener.blog comments powered by Disqus