July Gardening Guidelines
by Keith C. Hansen, Extension Horticulturist, Smith Co. – Tyler, Texas
The transition into summer brings with it a change in gardening chores for the month of July. Gardening activities usually slow way down in the summertime as the temperature continues to climb into the 90’s. July is often a very dry month, and, like most years, can be very hot, too. So, we usually don’t start a lot of new garden projects, but there is always maintenance chores to do. And, we should consider starting the “fall” vegetable garden right now in July.
The best time to do any kind of gardening or maintenance is in early morning when it is not so hot, or late in the day after supper. Watch the heat, dress cooly, take frequent breaks, have plenty of water on hand and drink frequently. Here are a few items for the July gardening calendar.
Whether or not the preceding months have been kind with abundant rainfall, the gardener should now be alert for summer drought conditions which could occur at any time now. A typical pattern of the last several years has been for rainfall to be shut off in early July, leaving normally well-hydrated plants lacking sufficient water.
Proper watering is essential to keep plants healthy. The main rule of thumb is to water deeply and as infrequently as possible, as opposed to frequent, light sprinklings. This will encourage a deeper root system that can take advantage of a larger volume or “bank account” of water stored in the soil. Frequent and light sprinklings tend to keep the majority of plant roots near the surface of the soil. Plants with this type of root system are more susceptible to extreme heat and water shortages and are easily stressed during the summer.
One of the best strategies for getting shrubs and young trees through summertime dry spells is to apply a thick layer of mulch over the root systems of plants. All organic mulches break down over time, so if it has been awhile since you’ve mulched, carefully check all plants in your yard. A three to four inch layer will prevent most evaporation from the soil and significantly lower the soil temperature in the root zone, reducing stress on the root system. Common materials used for mulch include pine needles, pine bark, cypress bark, aged grass clippings (let them thoroughly dry before using), shredded paper, sawdust (aged is best).
There is an excellent Texas A&M AgriLife Extension Service internet publication called Efficient Use of Water in the Garden and Landscape which describes proper water techniques for all types of garden and landscaping, including an extensive explanation of drip irrigation.
For more information on managing your plants during a drought, visit Earth-Kind Drought Preparedness. Other irrigation information and links can be found on East TX Gardening Water Page and water links.
Lawns at this time of year are rapidly growing and need frequent mowing. The best lawns will be those that are mowed regularly. If you mow often enough, you can return the clippings back to the lawn. The rule of thumb is to not remove more than 1/3 of the length of the blades per mowing. This may mean mowing every 5 or 6 days instead of once a week (or less). Removing more than 1/3 is stressful on the lawn, and will tend to leave visible clippings on top of the grass.
As rainfall becomes less regular, irrigation will be need to be more frequent. Lawns need about 1 inch of water per week. This can be supplied in one or more applications per week, depending on the soil type and how hot and dry the weather has been. Sandy soils need more frequent watering, as do newly planted lawns.
Watch out for lawn pests. Chinch bugs multiply rapidly in warm weather, and their feeding causes St. Augustine grass to look like drought stress. No treatment is needed until symptoms first appear. Look for wilting grass which does not respond to water. The grass will continue to dry, giving it a burned look. Look for tiny, 1/6 to 1/5 inch bugs scurrying quickly up and down grass blades and or scurrying to hide down in the thatch. Flooding the perimeter area with water, or soaking the edge with soapy will drive them up from the thatch onto the grass blades where they are more easily seen. Damage usually occurs first in the hottest and driest parts of the lawn.
July and August is also the time to treat for white grubs if there is a problem. Treatment is based on whether grubs are present in the turf and the way to find out is to dig a few test areas and look for the small grubs in the soil. Not all lawns will have grubs and excessive use of pesticides can lead to other turf problem and contamination of sewer discharge, so it is better to check first rather than automatically treat.
Harvest vegetables regularly from your garden to keep it productive. Letting squash turn as big as baseball bats will cause production to go down. Harvest vegetables at their peak of maturity for maximum nutrition and quality.
Begin preparing for the fall garden in July. That’s right! It may seem odd to start a fall garden in the summertime, but you need to get plants started in time for harvests before first freeze.
Examine existing plants you might consider carrying through to fall. Tomatoes often are not replanted, but if they are covered up with spider mites (they’re often bad by this time of year), seriously consider replanting this month. You’ll need to pamper new transplants a little to get them started, but they’ll be ready for a great harvest in October when quality will be high!
Do not plant the same vegetable type in the same spot year after year. Soil-borne diseases will build up and eventually cause major problems. Add compost or other organic matter, and composted manure, cotton seed meal or other fertilizers to the garden spot before tilling. Also, if you thought plant growth was poor this spring, check the pH of your garden soil before adding nutrients, and add lime if needed.
Besides transplanting tomatoes in July, other vegetables that can or should be transplanted this month include eggplant (7/15 – 8/1) and peppers (7/1-8/1). Other crops that can be started from seed this month include Lima beans (7/15 – 8/15), cantaloupes (7/15 – 8/1), southern peas (7/1 – 8/1), pumpkin (7/1 – 8/1), summer squash (7/15 – 8/15), winter squash (7/1 – 7/15), and watermelon (7/1 – 8/1) [(dates in parenthesis indicate optimum planting window for best results].
Here’s a tip for getting seeds up in the heat. Make your rows and open up a furrow. Soak the bottom of the furrow with water and then sow the seed, covering it with dry soil to the proper depth. This will help prevent crusting. Finally, lay boards or wet burlap down the row to give some more protection from the intense heat. Check every day; once germination begins, remove the covers.
Drip irrigation combined with mulch is an excellent way to maintain high quality vegetable plants throughout the summer. Drip systems are easy to install and require less water than sprinkler or furrow irrigation. Usually drip systems need to be operated frequently (how often depends on soil type and drip system) to adequately supply water to the plant’s root zone. Frequently check emitters for clogging.
If you are still looking for summer color to plant, you are not out of luck. Marigolds, cosmos, vinca (periwinkle), gomphrena, cleome (spider flower), zinnias, purslane and portulaca all do well in the summer heat. As a matter of fact, marigolds planted in late summer and carried into fall tend to have brighter colors than spring-planted marigolds. Spider mites, the number one pest of marigolds, are not as prolific during the cooler days of fall as they are in the summertime.
Plant bright, tropical color with esparanza (yellow bells), firebush (Hamelia), allamanda, mandevilla, Mexican heather, tropical and perennial hibiscus, bougainvillea, and pentas. Copper plants should be planted now so they’ll have time to grow before they turn the reddish copper color in the fall.
Be sure to cut off faded flowers before they set seed (called deadheading) to promote new growth and more flowers. Once a plant’s energy goes to maturing seeds, blooming will slow down or stop.
Chrysanthemums should be fertilized and pinched back this month. Pinching makes them bushier and produces more blooms for the fall. They will start setting flower buds in August.
OTHER MAINTENANCE TIPS:
Prune hydrangeas right after bloom if you need to cut them back. Flower buds are formed in late summer and early fall, so late fall and winter pruning removes these buds and eliminates next year’s flowers.
Blackberries need to be pruned now that harvest is ending. Remove the dying fruiting canes and tip back the vigorous, new growth two or three times to form a dense hedge for greater fruit production.
Plants in containers and hanging baskets need to be frequently watered in the summer to keep them from drying out. All this water leaches out plant nutrients from the soil. Use a water-soluble fertilizer regularly to keep your plants growing and healthy.
Now is the time to plan for next spring. Consider digging and dividing any crowded spring-blooming bulbs. Once the bulbs have matured and the foliage has turned brown, it is time to spade them up and thin out the stand. Crowded bulbs produce fewer and smaller blooms. They usually need thinning every 3 to 4 years.