Originally created 07/16/04
Gardens, landscape demand plenty of care during July
By Special Columnist
July is a busy month in the landscape. Here are some tips:
Plants more often wilt from lack of oxygen than lack of water. When soil is compacted, tender feeder roots and root hairs suffocate. The problem is compounded when gardeners assume this is a sign of water stress and immediately irrigate.
Well-aerated soil, enriched with organic matter allows air and water to circulate freely about the root system creating a vigorous plant.
Water plants several hours before applying pesticides, especially in dry weather. Drought-stressed plants have less water in their tissues, so chemicals that enter the leaves will be more concentrated and may cause burns.
Spider mites thrive in hot, dry weather, leaving webs on the undersides of leaves and eggs in the webs. Feeding mites leave infested plants appearing grayish and stifled.
For mild infestations, spray foliage with water to wash off the mites. For severe problems, spray with an approved chemical according to label directions.
There are not many good, effective miticides available for the homeowner market. Walter Reeves, a former extension agent and the host of the garden show on Georgia Public Television, recommended Ortho Systemic Insect Killer (formerly Isotox).
Inspect houseplants for signs of insect damage. Pest control is easier and safer while plants are outside in the summer than after you bring them in this fall.
Avoid pruning spring-flowering evergreens. Azaleas and camellias have started setting flower buds for next winter or spring's blossoms. Pruning will reduce or remove next year's flowering potential.
The second generation of whiteflies is emerging and might damage gardenias, tomatoes, peppers, eggplants, and squash. Hang yellow sticky traps among your vegetables to trap them. Do the same with gardenias. Because you won't be eating them, you can also control whiteflies on gardenias with systemic insecticides such as the Ortho Systemic Insect killer or you can use Di-Syston (disulfoton) or Bayer's Tree and Shrub Insect Control (imidacloprid).
Many lawn weeds are signs of poor growing conditions for turf grass. Chickweed and violets during the cool months often sprout up in places too shady for most turf grasses. Sorrel, daisies and dock are a sign that the soil is becoming acid because of poor aeration and drainage and lack of humus. Wild mustard, morning glories and quack grass warn of crusty soil and possibly hand-pan development. The presence of moss indicates soil compaction, poor drainage, low pH, or too much shade. Before you try to control the weeds, consider improving turf conditions.
If you irrigate your lawn, consider reducing the overall lawn size to save water. For example, try joining trees into beds with shrubs and ground covers. Also try to eliminate hard to irrigate lawn areas, such as narrow strips between a walkway and a building, or irregularly shaped areas.
I continue to get many calls about fire blight on Bradford and other callery pears, fruiting pears and apples. This can be identified by looking for blackened twigs and branches.
The disease can spread and kill the tree if it is not controlled. Remove all blighted twigs, cutting eight inches below the infected area. Disinfect pruning tools after each cut to prevent spreading the disease. Dip the blades in a solution of one part household bleach and nine parts water.
Many gardeners want to spray Roundup in plant beds to kill weeds but fear getting the Roundup on the foliage of desirable plants. Try using a piece of cardboard such as the side from a box to form an effective and portable barrier next to the desired plants.
By changing the angle of the cardboard, it's easy to spray weeds growing right up to the base of a desirable plant while shielding the stems, branches and leaves. Since some herbicide will get on the shield, the same side should always face the sprayer when moved from one location to another.
Sid Mullis is director for the University of Georgia extension service office in Richmond County. Call 821-2349, or send e-mail to smullis@uga.edu.
