An overnight thunderstorm has left our township with a serious power outage this morning, and it is too wet outside to garden. So, this looks like a good time to write this month’s checklist and see what we have to look forward to in the month of September.
Woody plant care
September is the recommended time to plant trees and shrubs. Maples and oaks are always appreciated for their fall color, but there are other less-used trees to consider at planting time. Dogwoods produce red leaves and berries in the fall. Redbuds have interesting heart-shaped leaves that turn yellow, and fringe trees have dark yellow fall foliage.
Annual and perennial care
September is a good time to refresh your summer containers with plants that will tolerate the colder temperatures.
Annuals that will live until frost include pansies, amaranth, nasturtiums and decorative forms of chard, peppers, kale and cabbage.
A couple of the more unusual perennials that do very well in the fall months are anemones and solidagos.
Beautiful and delicate anemones come in pink and white. Their forms range in size from small front of the border plants to larger forms for the middle and back. They will bloom until frost.
Solidagos or goldenrod hybrids offer late season, bright yellow bloom. They can be used in the middle or back of your garden. (Native goldenrod has been considered to be a major allergen for years but has recently been relieved of this reputation. Since the pollen of goldenrod is very sticky, it cannot be airborne. Goldenrod in the wild is frequently found growing next to ragweed, which is an allergy problem.)
Fall is an excellent time to divide perennials. Dividing them now will reduce your spring chore activities. Begin by lifting the perennial clump from the ground with a shovel or fork. Cut or gently pull apart the sections of the plant. Remove any broken stems or damaged leaves. Loosen the soil in the new planting area and set the plant section in the hole at the same level at which it was originally growing. Fill the hole with soil and water. The new plant will now have time to begin to grow before cold weather.
Mid-September is the best time to fertilize lawns with a 3-1-2 or 4-1-2 fertilizer.
Reseed bare or thin areas with an appropriate grass seed mix as needed.
Fruit and vegetable care
Fall raspberries should be ready for harvest.
Mid-September through mid-October is prime planting time for garlic. Plant garlic 3 to 5 inches apart and mulch with straw. Harvest next July when tops yellow.
Autumn Joy sedum is one of the signature September blooming plants for our area. Everybody loves it, but everybody has a major complaint regarding it. Just about the time Autumn Joy is ready to display its beautiful, large pink blossoms, a horrible thing begins to happen. The plant starts to fall apart and looks like someone dropped a large basketball right in the center of it.
The solution lies in early preparation. In spring as the sedum shoots begin to appear, grow-through plant supports should be installed. These supports are circular in shape and contain a grid design in the central portion. ‘Autumn Joy’ will then grow up through the support and unsightly flopping will be avoided. At maturity, the support will be completely hidden. These grow-through supports can be stored and used year after year. You can find these supports at local garden supply stores.
• The Master Gardeners are available to answer your questions. Call 815-758-8194 or email DeKalb_mg@extension.uiuc.edu.