Gardening: Dealing with the hot and wet summer

Eileen Ward
Tropical Ixora likes low pH soils and plenty of space to grow. The spots on the leaves are from lack of nutrients, not a disease.

Second only to August, July is one of the hottest months with high temperatures averaging 90 degrees and lows averaging 75 degrees. 

We can expect at least eight inches of rain making July a very wet month. Heavy summer rains can cause nutritional deficiencies in some plants and annuals by washing nutrients through our sandy soil.

More:Gardening: Bulbous plants for Southwest Florida

An application of iron should green them up again. Watch your azaleas and feed them by late spring for strong growth that will give you flowers next spring. It is too late to prune your azaleas without affecting next years’ flowers.

Hibiscus and Ixora are in their glory during the hot summer months. A feeding of 8-0-8, or similar analysis, before the summer rains begin, will help keep the flowers on the plant. If they have been subjected to standing or copious amounts of water do not water or fertilize them until they have had a chance to dry out.  This is a good time to prune back hibiscus, Ixora and oleander to control their size and encourage healthy new growth.

Citrus trees need to be fertilized if you did not do it in June. This feeding will help your crop mature. Fertilizer should be scattered evenly beneath the canopy of the tree.  Be sure not to have fertilizer meet the trunk of any plant.  It can cause severe burn and rot of the bark resulting in poor health and possibly eventual death.

Do not fertilize your St. Augustine lawn in July. Bahia also needs very little fertilizer. If your Bahia lawn shows need for fertilizer you should have applied a light application of ammonium nitrate in late spring to revive it. Apply to a dry lawn and water in immediately to avoid burning the blades of grass. Be sure not to scalp your lawn too short to avoid scorching of the crown and roots by the hot summer sun.

This is a good time of year to grow roots in your lawn. Remember, the longer the blade the deeper the root. However, it is also important to remember to mow frequently enough to avoid mowing more than one-third of the blades at a time.  This can prove difficult when summer rain storms can dump five or ten inches at a time. Take advantage of the rains to sprig St. Augustine plugs or Bahia seed in any bare spots in your lawn.

Chinch bugs, sod webworms and mole crickets are all active so watch for and treat as necessary.  Areas damaged in the dry spring months will be more susceptible to both insect and disease problems.  Watch for leaf and root disease on St. Augustine grass. A preventative treatment of fungicide would help ward off disease problems in spring stressed lawns. A fungicide such as Banner Maxx, Bayleton, Eagle, Heritage or Cleary 3336 can be used as a preventative treatment for Take-all Patch or other diseases on your lawn.

Scale, aphids and chewing insects can all be a problem on your ornamentals in July.  Worms and weevils will chew along the edges of the leaves, while grasshoppers and katydids chew holes in the center of leaves.

Diseases are active on ornamentals, flowers and vegetables.  Watch for powdery mildew, leaf spots, blights and rots.  This is a good time to prune your plants by removing crossing or diseased branches. Timely treatment with a fungicide and good housekeeping of fallen leaves and twigs will help keep diseases in control.

Some annuals to plant for the hot weather include daisies, zinnias, marigolds, pentas, lantana, salvia, or vinca. Divide crowded beds of bulbs and rhizomes when they stop blooming to assure larger blooms next year.

Fruits which ripen in July include avocado, carambola, guava, mango, natal plum, passion fruit, papaya and pineapple.  This is a good time to plant fruit trees and bananas.

If you planted your poinsettias after Christmas, they may need some attention.  Scab can be a problem in July.  This is a disease which looks like a scab on your skin and can be controlled with copper fungicide.  Prune poinsettias now to promote branching which will result in more flowers this winter.  Watch for horn worms as they can defoliate a plant in just a few days. The horn worm is a large green worm with a sprig on its posterior end.  Its light green color blends in with the foliage so look closely to find it.

Be sure to keep your roses fertilized after every flush of bloom. You may need to spray on a weekly basis to control black spot and powdery mildew.

Some flowering plants now blooming are Ixora, flame-vine, crape myrtle, hibiscus, and one of the most beautiful, the night blooming cereus. It is worth a trip outside after dark to see this one. 

You will need to pay close attention to your lawn and shrubs now since insect pests and disease are very active in the hot, wet month of July. This is not a month for faint of heart gardeners!

More:Gardening: Avoiding storm damage

Eileen and Peter Ward have owned a landscape and lawn maintenance company for 35 years. Eileen can be reached at or 239-394-1413.