Petunias (top two photos) and crape myrtles (lower) thrive in the heat of summer.



What to do in July

Sow seeds now for late summer and fall flowers such as marigolds, zinnia, petunia (photos at left), portulaca, and ageratum. Seeds are much less expensive, but transplants from the garden centers or nurseries will provide color faster.

Many drought-tolerant plants will perform better if planted in warm temperatures. Remember that even xeric plants need water regularly for about one year until the root systems are established.

Tomato transplants can be planted now for fall gardens. The best varieties are Surefire, Celebrity, Heatwave, Merced, and cherry types. Transplants must be acclimated to the sun in order to prevent sunscald from occurring.

Warm season grasses can be planted but an abundant amount of water will be necessary until the grass is established.

Remove seed heads from crape myrtles (photo at left) immediately after the petals fall. This will stimulate new flowers.

Mow lawn once a week and be sure the mower blades are sharp.

Remove dead, diseased, and damaged branches from trees and shrubs. Prune trees to allow more light through to grass areas beneath. Never top trees!

Remove old rose blooms from bushes by pruning to the second set of five-leaflets.

Soak hanging baskets in a tub of water every few days between regular watering. Always water plants before fertilizing.

Apply nitrogen fertilizer to roses in late July to give you better flowers in September and October. Water thoroughly after applying fertilizer to avoid damage to the roots.

Apply iron sulfate to plants that are showing yellow leaves with green veins. Keep iron sulfate and other iron products off the sidewalks and houses.

Use 20-20-20 or a similar analysis on container plants and water thoroughly.

Be on the lookout
Recently transplanted plants have inadequate root systems, and drought can damage them. Check them carefully and water when needed. If plants suffered from a freeze last winter, the additional stress from drought could cause death to a plant.

Check for blackspot on roses and spray with a registered fungicide.

Spider mites are most common in hot weather. Look for tan speckles on lower leaves. Plants may turn brown and crisp where severe infestations occur. Control with a miticide such as Kelthane.

Chinch bugs in St. Augustine grass will cause dried areas in sunny parts on the lawn. Chinch bugs are black and white with white diamonds on their wings.

White grub worms will show up six weeks after the major June beetle flight. Be on the lookout for these damaging insects in the lawn and flowerbeds. Treat only if there are five to seven grubs per square foot of soil. Diazinon, Merit, Oftanol, or Grub-X can be used.

Aphids on oaks, pecans, crape myrtles, and other trees are a problem creating honeydew. First try a high-pressure spray of water before applying chemicals. Use a registered, general insecticide.

Miscellaneous chores
Water garden and lawn as needed, giving a thorough soaking rather than frequent light sprinklings. Sandy soils will need to be watered more often. Be sure to avoid water run-off.

Add mulch if needed to flowerbeds and around shrubs. This helps to reduce water and weeds.

Many spring-flowering shrubs and fruit trees will be forming flower buds in late July and August. Drought conditions can reduce both the quality and quantity of spring flowers. Don’t allow them to suffer drought stress.

Clean up iris beds and thin out clumps if crowded. They can be transplanted from July until October.

    (c) 2007 - 2008 Howard County Master Gardeners