Plant Answers

Primetime Newspaper
By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist
Week of September 3, 2007

“September Gardening Calendar”

September is an important month for lawn and gardening tasks.

Early in the month apply pre-emergent herbicides if you had trouble with cold weather weeds last winter. Pre-emergent herbicides, when they are applied as the label requires, prevent seeds from germinating. That is great if you are trying to prevent bedstraw, rye grass, annual bluegrass, thistles, or rescue grass. It is not good if you are trying to grow wildflowers. Late in the month or early in October it is time to apply a winterizer fertilizer. The winterizer fertilizer does not cause a growth spurt because by late September, the grass has changed its chemistry to one of preparing for the winter and for next spring. Look for “winterizer” on the label. If you have an open bag of slow release lawn fertilizer that will work fine.

It is also important to reduce watering in the autumn to reduce brown patch. With all the rain we have had, your sprinkler should be off anyway. A wet lawn in the fall when temperatures moderate is likely to be infected with the fungus.

In the vegetable garden, plant green beans and beets. Also fertilize your tomatoes with one-half cup of slow release lawn fertilizer or winterizer fertilizer. Control stink bugs with spinosad or Sevin. Caterpillars and pin worms will also be killed by spinosad or Sevin, but Bt products are also effective. Thuricide, Bio Worm Killer, and Dipel are Bt products. For webworms on fruit trees the above named insecticides work well. Spray them as high as you can in pecans with the hose-end sprayer or just ignore the webworms. They will not cause permanent damage to the pecan trees. Pawnee and other early maturing pecans will begin falling in September. The quicker you get them off the ground and into the refrigerator, the longer the quality will last. Many pecans this year have been stung by stink bugs or infested with pecan scab, a fungus disease. Nut quality can be affected.

This month is good for planting wildflower seed. Select an area in full sun where the seed can reach the soil. A weedy or sod covered field is not the best site. Mow the weeds down before applying the seed. Minimal soil preparation is required, but a raking will increase germination success. Most wildflowers varieties germinate in the fall, hang on through the winter and then begin real growth in the spring.

The waves of migrating hummingbirds show up this month. Watch for black chins, ruby-throated and rufous hummingbirds. One or more sugar water feeders and potted firebush and pentas will bring them to your patio for easy viewing.

In the flower garden keep your hot weather flowers weeded and protected from insects. It is too early to plant cool weather flowers. Wait until next month.

Pecans are very prone to limb breakage. This year with the full crowns and large nut crop they have been breaking at an alarming rate. Some horticulturists believe you can reduce the chances of limit breakage by trimming off some of the pecans. Prune off the end nut clusters of as many limbs as you can reach with a pole pruner.