Houston's weather is often inconsistent, making it tough on gardeners. Summer temperatures above 90 degrees F. can extend well into fall, and spring weather may occur in the middle of winter. Houston falls into USDA hardiness zone 9b, with its northern suburbs in zone 8a. Some varieties of cold weather vegetables do not grow well in hot summer weather, so select varieties bred for warmer climates.
Mark off your garden plot with stakes and string. Your garden should be located in an area that receives full sun for at least six hours a day.
Take a soil sample from your garden for a soil analysis test. Dig a quart of soil from up to 10 random locations throughout your garden. Mix the soil samples and remove debris such as plant material and rocks. Allow the soil to dry and place 1 cup into a clean plastic bag for sampling. Take the soil sample to your county extension service. Extension agents will provide you with paperwork and instructions for sending your sample to the Texas A&M Soil, Water and Forage testing facility. Test results are generally returned within three weeks. The soil test results will reveal your soil’s pH, structure and recommended amendments.
Break up your soil to a depth of 12 inches with a rototiller. Spread soil amendments recommended by your soil test in a 4-inch layer over your garden soil. Good soil amendments for Houston include gypsum (to break up the black clay of Houston black soil), compost, peat moss and composted manure to improve drainage and add nutrients to the soil.
Plant cool-season vegetables such as cabbage, broccoli or celery in October and February. Plant warm-season vegetables such as okra, tomatoes and summer squash in early April. Hybrid tomato varieties such as Solar Fire, Heatwave, Spitfire and Sun Master were developed specifically to produce fruit in warm-weather conditions. Space each plant far enough apart so air can circulate between the plants to prevent fungus and disease in Houston’s humid climate. To plant seed, create furrows or drill holes in the soil with a rake. Place the seed twice as deep as the seed’s diameter at the widest point and cover with soil. Dig a hole for the root ball that is slightly wider and deeper than the root ball. Place the plant’s roots in the hole and cover with soil. Water so the soil remains as damp as a wrung-out sponge.
Cultivate between plant rows with a rototiller and around plants with a rake and hoe. Weeds will steal nutrients and water from the soil that plants need.
Check the soil daily and water during drought conditions. The soil should remain as damp as a wrung-out sponge.
Harvest vegetables as they become ripe to encourage the plants to continue producing vegetables.