September Garden Tips
By the Tarrant County Master Gardener Association, Texas Cooperative Extension Office.
Phone 817-884-1944 for answers to any gardening question.

Fall is a good time to test your soil, especially to determine the pH, which tells you the acidity of the soil. You will also learn the correct fertilizer blend to apply for the best growth during the fall growing season.

Examine your flower, ground cover and shrub beds for unwanted volunteers - seedlings of invasive shrubs and trees, green briar, sedges and other unwanted weeds. If they are already well established, soak the ground to make them easier to pull. A pair of pliers may also help get woody plants out of the ground.

Check the soil below trees, shrubs and prepared beds with your fingers or a moisture meter to make sure the rootball and soil are getting enough water. The soil should be moist but not soaking wet. Just because it is hot doesn't automatically mean the soil is dry 3 or 4 inches deep. Check it out that deep to be sure. Don't allow plants with green fruit or berries to suffer from lack of moisture. Hollies will frequently drop their fruit under drought conditions. Some vegetables such as cucumbers or eggplants also become bitter if under watered during peak growing times.

Keep container plants well watered and fertilized for the best fall show. Soak the root ball by placing the pot in a container of water for 15-30 minutes until well moistened. Proper care will keep them lush and attractive through fall.

Prune out dead or diseased wood from trees and shrubs. Hold off on major pruning until mid-winter. Pruning now may stimulate tender new growth prior to frost.

LAWNS

Lawns need special care this month. Especially after our heavy spring rains, the sudden change to August heat may have damaged roots. Keep lawns evenly moist with one inch of water once a week.

September is the time to apply lawn fertilizer. Fall fertilized lawns are healthier and better equipped to make it through the winter and resume growth next spring.

If you had weeds last spring, they would have been cool-season weeds that germinated last fall. A pre-emergence herbicide (weed preventer) applied this month will help reduce the weeds next spring (unless they are perennials like dandelions). Avoid pre-emergent herbicide applications on newly planted or weakened grass or in dense shade. Carefully follow label rates of application, since applying more than is called for can damage your lawn.

The hot, dry weather encourages chinch bugs that make St. Augustine look drought-stricken. Lawns that suffered dieback from drought, chinch bugs or disease can be safely sodded in September. It's too late to try to establish Bermuda or Centipede from seed, but ryegrass and tall fescue can be sown toward the end of the month.

FLOWERS

Remove weak, unproductive growth and old seed heads from crape myrtles and roses the first week of September to stimulate new growth and a final burst of fall color. Don't take off much, no more than a quarter of the growth. Make a light application of fertilizer, and watch for black spot disease that can be a problem. Continue a disease spray schedule on roses as blackspot and mildew can be extremely damaging in September and October.

Sow spring wildflower seed now; these can be purchased or seeds you gathered yourself from dried seedheads earlier this year. Soils should be lightly cultivated prior to planting. Consider bluebonnet, Indian paintbrush, coneflower, fire-wheel, black-eyed Susan, evening primrose and other native flowers. For more reliable, uniform seed germination of our State flower, purchase acid-treated bluebonnet seed. This treatment pits the seed coat, allowing nearly 100% germination in one to two weeks.

Divide spring flowering perennials such as iris, daisy, gaillardia, rudbeckias, cannas, daylilies, violets, liriope ajuga and other perennials. Move to new areas or share with friends and neighbors.

Create new perennial flowerbeds, and dig, divide, and replant those overcrowded perennials. Spread a liberal amount of organic matter evenly over the area and mix into the soil at least 6 to 8 inches deep. Space divisions at least 1 foot apart in all directions so root competition will not be a problem for several years.

Prepare the beds for spring-flowering bulbs as soon as possible. It's important to cultivate the soil and add generous amounts of organic matter to improve water drainage. Purchase spring blooming bulbs as soon as they become available in the garden centers, or mail order special varieties. Plant bulbs by loosening the soil and make a hole with a trowel or bulb planter. Don't mash the bulb into the soil or you may damage the basal plate (bottom of the bulb), causing it to rot. Bulbs will rot without proper drainage.

VEGETABLES

In early September, plant lettuce and mustard. Late in the month plant snap bush beans, Lima bush beans, beets, onion seed. Any time in September plant broccoli, brussel sprouts, cabbage, cauliflower, collards, cucumber, parsley, English peas, Southern peas, radish, spinach, turnips greens and turnip roots.

These Garden Tips courtesy of the Tarrant County Master Gardener Association