August 2007

August is a good time to start thinking about starting a compost pile. As we go later into the growing season and fall, dead plant material is more readily available for composting, plus we have all the fallen leaves. The Chicago Home Composting Program has an excellent, well-illustrated booklet on the basics of composting. Call 773-233-0476 for the booklet or check out their web site at www.chicagohomecomposting.org.

Now is the time to plan a fall vegetable garden. Kohlrabi, leaf lettuce, turnips, collards, mustard greens, radishes, spinach and Chinese cabbage can be seeded for a fall harvest. With an October 15 date as an average date for our first killing frost; look for varieties that will mature within 70 days. With warm summer temperatures, keep the seeds moist after planting.

If it is August, it must be powdery mildew time. Powdery mildew is a very common problem especially during wet summers and at the end of the growing season. Powdery mildew leaves white spots on leaves, shoots, buds and stems. It really doesn’t harm the plant, but it doesn’t look good. To avoid mildew space plants properly for good air circulation. Try to avoid wetting the foliage when watering because that can help to spread the disease. Buy varieties of plants that are resistant to mildew.

Avoid fertilizing roses after mid-August. Fertilizing roses after mid-August can promote new growth that will not have time to harden off before cold temperatures set in. After roses have gone dormant, you can fertilize and the fertilizer will be available to the plant in the spring.

August through mid-September is the best time to repair lawns. Seeding bare spots in the lawn during this time period will allow the new growth to have enough time to germinate, grow and harden off before cold temperatures arrive. There is less competition from weeds in the fall because a lot of the annual weeds are dying out. Plus we are usually blessed with cool temperatures in the fall which is great for growing grass. Ideally dig the soil to at least 6-8 inches deep, spread grass seed over the area and tamp down. Keep the soil moist until germination. Cover with weed free straw to conserve moisture. If you are laying down sod, water the new sod several times a day for 1-2 weeks until it begins to knit or take hold. Be sure that water goes down through the thick sod and moistens the soil underneath for good root development. Do not let sod dry out.

Watch for cicada killer wasps in the lawn. Cicada killers are 2 inch long black wasps with yellow bands. The female wasp makes a 7 to 10 inch burrow in the ground. She will sting a large insect, drag it into the burrow, lay an egg in it and cover up the burrow. She will repeat this process several times. The eggs hatch into larvae that eat the insect. Male wasps act as guards for the nests, hovering in the area. They confront human intruders by zigzagging back and forth in front of their face. Males are unlikely to sting; females will sting if stepped on. Cicada killers most often build a nest in bare soil. Mulching or planting groundcovers in bare areas may reduce the problem. To deter the wasp, cover kid’s sandboxes when not in use and replace sand under playground equipment with mulch.

Fall is a good time to plant trees. At the University of Illinois Plant Clinic, the most widespread tree problem they see is decline in trees that were planted too deeply. When buying and planting trees remove soil that is covering the root collar. The root collar is where the roots meet the trunk. The tree trunk should flare at the soil line. If the trunk goes into the ground looking like a telephone pole, it has been planted too deeply. Dig a hole two to three times as wide and just as deep as the root ball. No soil amendments or fertilizer are needed, unless you want to use a slow release fertilizer. For a fact sheet on planting trees, call 773-233-0476.