Nights with freezing temperatures return in October. Some gardeners welcome the first killing frost and look forward to more time for relaxing or planning next year’s gardens. Others wish to prolong the season and are prepared to cover tender plants whenever freezing temperatures are predicted. Sheets or lightweight tarps spread loosely over plants such as petunias, begonias or impatients will trap the heat stored in the ground overnight and prevent freezing damage. Sometimes plants protected for one or two nights will keep growing and blooming for several more weeks until the really cold weather arrives.
Tropical plants are becoming popular additions to many decks, patios and porches. As the name implies these plants have no frost tolerance and must be brought indoors or covered before any freezing temperatures. Some plants such as hibiscus and mandevillas can be carried over the winter in your home next to a patio door or large window where they will receive good light.
Tulips provide more spring color than nearly any other plant and are best planted in October. Drifts of a dozen or more bulbs of one variety make the most impact and can be easily planted by digging the whole planting area 6”- 8” deep, space the bulbs according to the package directions, fill in the soil and water well. Bulb fertilizer may also be incorporated below the bulbs.
Garden cleanup in the fall should include removing any diseased plant tops but healthy perennials, ornamental grasses and some annuals can be left standing for winter interest, to catch snow and provide seeds for birds.
Fall is a great time to plant trees and shrubs. The new plants will have several months to grow new roots and will be ready to grow early next spring. Consider adding some plants with great fall color such as sugar maple, ginkgo, burning bush or the University of Minnesota hardy blueberries including ‘Northblue’, ‘Northsky’ and ‘Polaris’.
Trees that bleed or are susceptible to disease if pruned in the spring may be pruned now. This includes maples, birch, black walnut, oaks, honey locust and mountain ash. Prune young trees to a single central leader; remove broken, crossed or rubbing branches; and gradually remove lower branches. Always make proper pruning cuts just beyond the branch collar but not leaving stubs.
Continue watering trees, shrubs and evergreens until the ground is frozen. 4” -6” of woodchips, bark or other mulch spread under trees and shrubs will help hold moisture and reduce winter injury if we don’t have insulating snow in mid-winter.
Continue mowing as long as your grass is growing. Most modern mowers also do a good job of mulching tree leaves if they aren’t too thick. Heavy accumulations of large leaves from oak and maple trees should be raked and composted.
If you only fertilize your lawn once a year October is the best month. Even after the grass leaves stop growing in late fall the roots continue to grow and fall fertilization insures that your lawn goes into winter in good condition and helps with early green-up next spring.
Fruits and Vegetables
The best Minnesota Grown apples including Honeycrisp TM, Regent, Honeygold, Fireside and Keepsake are available in October and are available at local orchards, fruit markets and grocery stores through mid-winter. If you grow your own apples pick them just when the color and flavor peaks and while they are crisp and juicy.
Squash and pumpkins should be harvested when they have bright color and a thick, hard skin. These vegetables will be abundant in farmer’s markets and stores and make a colorful and healthy addition to fall dinners.
Clean up fallen apples, apple leaves with spots, over-ripe vegetables and tomato plants that had disease problems this year and dispose of them off of your property. Many of the disease and insect pests overwinter in plant material and good sanitation will reduce pest problems next year.