September is usually a mix of summer and autumn days as the day length shortens and the weather starts to cool ever so gradually. A lot of our spring and summer blooming annuals get a fresh burst of energy as fall approaches and they produce a new round of growth and flowers as we confront the last two mouths of the normal Oklahoma growing season.
There are a number of plants we traditionally plant in the fall. As football season starts we often think of hardy mums or chrysanthemums. Most garden centers produce a nice crop, already in bud, that you can plant in your front flowerbeds, by the back porch or patio or in decorative containers for impressive fall color. Hardy mums set bud by day length as the day gets shorter. Some varieties are already showing color while other varieties will color up over the next few weeks. Hardy mums produce mounds of color in white, yellow, orange, rust, bronze, red, pink, purple and an assortment of mixed colors and will generally be showy up through Halloween and until the first hard freeze. There are varieties with clusters of small flowers or larger single flowers from simple daisy type flowers to spoon petal flowerheads and double dahlia style flowers to add variety and interest to your hardy mum plantings.
You can buy hardy mums from the smaller 4” pot transplants to one, two or three gallon size containers or even larger bushel basket sized specimens depending on the amount of plant and flower impact you want this fall. If hardy mums are watered and cared for through the year they will freeze to the ground this winter and then re-sprout next spring. After producing vegetative growth through the spring and summer they will flower again when the short days will trigger another round of fall flowers next year.
We usually let the temperatures cool a little more before planting the semi hardy pansies, viola, ornamental kale and cabbage. These semi hardy plants like cooler temperatures and will wither under the increasing heat late next spring. We suggest planting these cool season crops starting later this month, after you are done planting hardy mums which can be planted now. Don’t forget to water in new plantings and to be ready to water more when we are not receiving regular natural rains.
Now until mid October is a great time to plant or over seed tall fescue grass seed if you want to establish a green lawn for the winter months and for after your Bermuda or other warm season grass has frozen back to brown for the year. You can also sow annual or perennial rye grass or Kentucky 31 Fescue seed to establish a green cover crop on bare land to prevent blowing or erosion until you can plant your permanent warm season lawn grass next spring.
Fall is a fabulous time to plant container grown trees and shrubs. Fall plantings don’t have to battle such intense heat and our scorching, dehydrating summer winds and they will generally benefit from more regular autumn rains as they get established. The roots will keep growing well into the winter and this will help your new trees and shrubs get established before facing the extreme heat of next summer.
This is a beautiful time of year to be outside in your yard and garden. Enjoy the re-energized flowers and vegetables as you do your watering, weeding, and while planting your hardy mums.
Rodd's Seeds of Wisdom 