August 2004

Ornamental

Renovate the bare spots in the lawn. Mid - August to mid - September is the best time for lawn renovation. Annual weeds are dying and temperatures are cooling, providing good growing conditions for germinating grass seed. For small, bare patches, rake the soil surface and broadcast the seed. Tamp the soil with the backend of a rake to provide good seed to soil contact. For large areas, dig or till the soil to a depth of 6 to 8 inches. Dig organic matter into the soil. Seed at recommended rates. Over seeding will cause weak and spindly growth. Keep seeded areas moist.

Watch for Septoria leaf spot on Rudbeckia. Dark brown spots appear on leaves and enlarge to form large browned to blackened areas. The disease will spread rapidly during wet weather. Watering the base of the plant and not the foliage will help to prevent the spread of Septoria leaf spot as will removing dead leaves at the end of the growing season. Copper based fungicides can be sprayed for control.

Be prepared for yellowjacket season. In late summer their numbers build and they are attracted to picnic foods - soda, hot dogs, hamburgers and juices. Yellow jackets are about 1/2 to 3/4 inches long with alternating black and yellow bands on their abdomens. Yellowjackets can sting repeatedly. Their nests can hold over 10,000 insects. For control, apply Sevin dust at or near the nest opening at dusk. Insects will bring Sevin into the nest as they exit and enter. Outdoors in picnic areas, keep food covered and garbage cans tightly sealed. Control is only necessary when the yellow jackets are in people frequented areas.

Watch for fall webworm webs in trees at the end of branches. The nests can be three feet long. The 1 to 11/2 inch long caterpillars have long white hairs running the length of their body. Webworms attack numerous trees including maples, oaks and elms. Pruning out the nest will provide control. When treating with insecticides, you must open the nest to spray the caterpillars. Damage is usually not extensive enough to harm trees.

Divide iris now. Cut back the leaves to about one-third their length. Dig and lift the clump. Separate the rhizomes with a sharp knife. Discard all the rhizomes that are soft. New transplants should have a fan of leaves with white roots. Select a sunny area for planting. Plant new roots in groups of three in a triangular shaped pattern. Dig a hole 6 to 8 inches deep and in the middle of the hole form a mound just below the soil surface. Place the rhizome on top of the mound while carefully spreading out the roots. Be sure to place the rhizomes, so that the fans of leaves face out from the center of the triangle. This will prevent crowding. Cover with soil, so that the rhizome is just below the soil surface. Water well.

Check for grub damage in the lawn. Dead, browned areas of grass that roll up like a rug is an indication of grub damage. Eight to 12 grubs per square foot will cause damage. Treat with a recommended insecticide and water it in immediately.

Edible

Sow radish, lettuce, spinach, beet and turnip seed late in the month. These vegetables will mature in the cooler fall weather.

Plant a green manure crop in empty garden areas. Sow seeds of oats, rye or buckwheat. These cover crops can be dug or tilled into the soil in the spring. Green manure will improve soil structure and will add nutrients to the soil.

Plant a final crop of beans in early August. Sow the seeds in a six-inch wide row, 1-2 inches apart. Cover with one inch of soil. Keep soil moist until beans germinate.

Win $5,000 for the best homegrown tomato in Chicago. NatureSweet Tomatoes at www.naturesweettomatoes.com is sponsoring the contest. Gardeners can pick up an entry form at Jewel grocery stores. Three tomatoes of the same variety should be brought for judging on August 28 at the Jewel grocery store at 7900 North Milwaukee in Niles, IL from 10 to 11 a.m. Three $250 store vouchers for runner-ups will be awarded. Call 773-233-0476 for more information.