|Photo by Audrey Stokes|
You and your fall garden benefit when you give your plants the same TLC in fall as you do in spring and summer. A vegetable garden left unattended through winter provides a cover for pests and disease.
Plant disease agents such as bacteria, fungi and viruses all remain alive, though dormant, during the winter months. By recognizing the places where these organisms hide, gardeners can often destroy them and prevent disease outbreaks the following spring. Many fungi spend the winter on or in old leaves, fruit and other garden refuse. These fungi often form spores or other reproductive structures that remain alive even after the host plant has died. Cucumber and squash vines, cabbages, and the dried remains of tomato and bean plants are all likely to harbor fungi if left in the garden over the winter.
Insects, too, survive quite nicely over the winter months. Cucumber beetle, Colorado potato beetle and Mexican bean beetle all overwinter as adults. In spring they migrate to young plants where they feed and lay eggs for a new generation. Insects and plant pathogens survive on weeds as well as on garden plants. Many weeds serve as alternate hosts for insects and fungi, helping them to complete their life cycle. Destruction of these weeds removes a source of future troubles.
|Powdery Mildew on Squash photo by Audrey Stokes|
Garden Clean Up Steps:
- Remove diseased foliage to prevent disease. Tomato, potato, and squash are the most likely culprits due to their susceptibility to powdery mildew (http://www.ext.colostate.edu/pubs/garden/02902.html). Do not toss these plants in the compost. Bag and discard.
- Dispose of all other plant debris including annual plants -- they may protect the egg sacs of insects over the winter.
- Thoroughly weed the garden but do not compost the perennial weeds. They will likely reseed themselves and become the bane of your existence if you use the compost in the garden the successive season.
- Some planting may also occur at this time when getting the garden ready for winter. Garlic (http://www.colostate.edu/Depts/CoopExt/4DMG/VegFruit/garlic.htm), for instance, is always best when planted in the fall.
- Consider mulch (http://www.ext.colostate.edu/mg/gardennotes/715.html) to be your garden’s best friend in both winter and summer to prevent weeds and retain moisture. Mulch to maintain soil quality, using weeds (but not those with seeds), cocoa hulls, grass clippings, chopped up leaves, or straw.
- An alternative to mulching is to plant cover crops (also known as "green manure" (http://www.ext.colostate.edu/mg/gardennotes/244.html) after harvest to correct soil compaction and help to fix nitrogen in the soil. Stripping the soil of all covering without snow is a recipe for erosion, so try planting a cover crop of rye, vetch or clover.
"They will green up and grow in the spring," says Carol O’Meara, Colorado State Extension Assistant Horticultural Agent for Boulder County, "and although rye usually is the quickest to germinate, they will have such a long period of striation through the winter that any of those would be okay." Striation is a period of cold that is required for some seeds to germinate.
- Other items on the list of winter prep for vegetable gardens are to remove any unused stakes, ties, and trellises and allow to air dry before storing. This is also a great time to clean and oil gardening tools.
Cleaning up your vegetable garden will help to reduce next year's disease and insect problems. In fact, good sanitation is one of the most important steps you can take to insure that next year's garden will be healthy. Follow these simple steps to help you through the season’s finale—and you will have a much healthier garden come spring.
For additional information check out these CSU Extension publications:
Insect and Disease Prevention for Next YearVegetables and Herbs