Planting vegetables in July might seem counterintuitive to novice gardeners, but it is an excellent time to sow seeds for a bountiful fall harvest in Galveston. According to Kimberly Mayer of Texas A&M AgriLife, warm soil and long summer days create ideal conditions for planting pole beans, transplanting eggplant seedlings, and planting summer squash from seed.
“These seeds germinate well in the warm soil that the summer sun provides, making them an ideal crop to grow in our South Texas heat," Mayer said.
“These plants can also stand up to the dog days of summer which bring brutal heat and humidity to our area.”
Protecting young plants from excessive heat can be challenging but manageable with some planning. “It can be a challenge to keep your plants healthy in the heat of the summer, but with a little planning, it can be done,” Mayer said.
“During the summer, soil moisture becomes essential for good plant production. Because continual watering is often costly and time-consuming, it pays to conserve the moisture around plants.”
Mayer emphasized the importance of soil moisture for good plant production, recommending the use of mulch to conserve moisture and improve overall gardening success.
“Continual watering is costly and time-consuming; it pays to conserve the moisture around plants. This is best done by mulching,” she said. “A good mulch will retain valuable moisture needed for plant growth and improve overall gardening success.”
Plants that are in containers can also be moved to the shade during the hottest part of the day. Remember that container plants need to be watered more often than in-ground plants, she said.
To mitigate the risks associated with heavy rain and potential flooding from tropical storms and hurricanes, Mayer said to remember to turn off sprinkler systems as part of a storm-preparedness plan.
“During a hurricane, there tends to be a lot of rainfall, so the trees do not need extra irrigation," she said.
The combination of wet soil and high winds can uproot trees, so it’s best to resume irrigation only after the soil has dried out. Mulch may wash away during a hurricane, so it will need to be replaced afterward. While rubber borders can help hold mulch in place, they can also trap water, so use them judiciously.
Fertilization should be avoided if a storm is imminent. Unabsorbed fertilizer can be washed away, potentially contaminating local water systems.
Ensuring proper yard drainage is also crucial. Landscape sloping away from the home can minimize flooding risks. Storm drains and culverts should be kept clear of debris.
Keeping the lawn trimmed will aid in water drainage and make post-storm cleanup easier. Mayer also recommends harvesting any ripe produce before a hurricane arrives to reduce waste and potential debris.
For those starting their gardens in July, proper soil preparation is key to a successful fall crop. Mayer advises getting a soil test done every two to three years to determine pH levels, salinity, and nutrient content.
“As my former colleague and fellow horticulturalist Skip Richter says, ‘brown stuff before green stuff.’ That means that it's vital to make sure your soil is healthy and prepped before even thinking about what you may want to put in the ground.”
Healthy soil is the foundation of a productive garden, so it’s vital to ensure it’s well-prepped before planting.
Common pests and diseases can also affect fall vegetable and fruit crops in Galveston. Spider mites and aphids are particularly problematic, thriving in hot and dry conditions or high humidity, respectively. Mayer recommends cutting off heavily infested foliage or using a hose to dislodge pests, paying special attention to the undersides of leaves where eggs and pests may hide.
For gardeners looking to extend their fall harvest into the cooler months, succession planting techniques and specific crops can help. Surprisingly, crops like corn and summer squash can be planted in August.
The key is to choose early maturing varieties that can be harvested before December freezes. "Stick with cultivars that are 80-90 days or less," Mayer advised.
With the right planning and techniques, Galveston gardeners can enjoy a productive and rewarding fall harvest, she said.
You can find more information about soil testing at soiltesting.tamu.edu. The local County Extension Office also has soil testing forms and bags.
Preparing the soil for fall gardens If you’re using an established garden area, pull out all plant material - the remains of your spring crop and any weeds that have grown up in the garden. Don’t put plant residue from a spring garden into your compost bin because it is likely to be contaminated with insects and disease pathogens.
For a new garden site, remove all the grass. Just tilling it into the soil will not eliminate all the grass sprigs; they will continue to grow and interfere with the garden. Likewise, for a raised garden, remove all turf before building the frame and filling it with soil.
Grass and weeds can be killed with an herbicide that contains glyphosate. Several products are available, including Roundup and Kleenup.
After removing the grass, shovel the garden area to a depth of 10 to 12 inches. Rototillers will not penetrate adequately, but they can be used to loosen and mix shoveled areas.
Spread 1 to 2 inches of coarse, washed sand and two to three inches of organic matter on the garden surface and till it into the soil to improve the soil’s physical quality. The soil will need to be improved over time rather than in just a season or two. If you are building a raised bed garden, don’t skimp on the soil. Use weed-free loam or sandy loam soil.
Adding fertilizer to the soil is the next step and there are two options.
Apply one pound of ammonium sulfate (21- 0-0) per 100 square feet (10 feet by 10 feet) before planting. Then sprinkle one tablespoon of ammonium sulfate around each plant every three weeks and water it in.
Or apply two to three pounds of a slow-release fertilizer (19-5-9, 21-7-14, or 25-5-10) per 100 square feet of garden area. Apply one tablespoon of ammonium sulfate (21-0-0) around each plant every three weeks and water it in. This second method should produce a more abundant harvest, especially with hybrid tomatoes and peppers.
Do not add too much ammonium sulfate, and do not put it too close to the plants. It can seriously damage them.
If available, horse or cattle manure may be substituted for commercial fertilizer at a rate of 60 to 80 pounds per 100 square feet of garden area. Never use poultry manure on a fall garden.
After adding fertilizer, mix the soil thoroughly and prepare beds on which to plant rows of vegetables. These beds should be 30 to 36 inches apart so you can move easily through the garden area when the plants grow larger. Pile and firm the planting beds.
Then water the entire garden with a sprinkler for at least two hours. Allow the area to dry for several days, and it will be ready to plant.
Courtesy of Fall Vegetable Gardening Guide for Texas - Texas A&M Agrilife Extension Service (tamu.edu)