September is the beginning of the fall season and gardeners have a second season for planting and maintenance in the landscape.
Remember the fall season is better than the spring season to plant trees and shrubs. The landscape nurseries are getting in new trees and shrubs so look for fresh newly arrived plants. A lightly leafed tree or shrub, roots showing at the top and bottom is not necessarily a good buy.
Early fall planting is best for container- grown shade and ornamental trees and pines. Trees that are planted in the fall will be twice as big as spring planted shade trees when measured the following fall.
There will be a lot of junk tree and shrubs left over from the spring sales so look for fresh, newly arrived plants. A lightly leafed tree or shrub, roots showing at the top and bottom is not necessarily a good buy. Actually, it is better to buy from established retail nurseries than the large chain stores because they put more into the care of their plants.
Many annuals begin to look spindly by late summer and early fall and need to be cut back for regrowth. Fertilize with about a teaspoon of a complete fertilizer to stimulate new growth. If they are too far gone, they may have to be removed and the soil in the bed prepared for the cool season annuals.
During the month of September, mums will be ready to plant. The shorter type mums, opposed to floral mums, are better for the landscape, since they don’t need to be staked. The best types are those that are labeled “garden” mums. These varieties bear many small flowers per plant and they stay uniform and short.
Transplanting perennials can be a little tricky if the gardener does not know each plants characteristic. A good “rule of thumb” is if a perennial bloom in the spring, transplant it in the fall. If it blooms in the fall, move it in the spring. If it blooms in the summer, transplant it in the late fall or late winter, before it starts growing.
Perennial beds that were so colorful earlier in the years should be cleaned now. After the foliage of the perennials have died down, remove the dead leaves, stems and spend flowers. These materials will often harbor insects and disease-causing organisms.
September is the time to plant tall fescue grasses in Southwestern Oklahoma. If over seeding bermudagrass or tall fescue, mow the grass as low as possible to get the seed in contact with the soil. If establishing new turf, till the area lightly to break up the soil and control any weeds. Apply about 6 to 8 pounds of seed per 1000 square feet and rake the seed lightly followed by firming the seedbed with a roller. Water lightly and keep the seed moist until germination occurs.
This month the pre-emergence weed control should be applied to the bermudagrass lawn. This material will control the seeds of annual broadleaf weeds and grassy weeds. The material must be applied before any seeds germinate and a thorough coverage is important to get a good control. Be sure to water in the material after application.
The last application of a nitrogen fertilizer should be applied before September 15. High application of nitrogen after September 15 could cause the grass to continue the leaf growth and not condition itself for winter. This opens the grass up to freeze damage if we have an early freeze.
It is not too late to start your fall vegetables. All of the leafy vegetables such as collards, spinach and Swiss chard as well as garlic, kale, kohlrabi, leek, green peas and turnip can be planted up to September 15. If you are carrying over tomatoes, okra, peppers, and sweet potatoes, one to two tablespoons of a complete fertilizer will help produce bigger and better tasting vegetables.