There are two main classifications for garden vegetables --- cool-season and warm-season. Cool-season vegetables grow best in hot climates when planted early in the spring or late in the fall, before the heat of summer. Warm-season vegetables tolerate the heat of mid-summer and can't withstand mild frosts or extended cold periods. Vegetable plants for hot climates include corn, tomatoes, cucumbers, melons and peppers. Keeping the soil slightly moist during hot spells helps these plants avoid dehydration and encourages healthy fruit production.
Perennial blossoms can provide a breath of fresh air in a simmering hot landscape. Perennial plants are those that come back year after year. Perennial varieties that withstand freezing temperatures often wither in climates with extended periods of summer heat.
Butterfly weed (Asclepias tuberosa) is good for hot weather and a type of wildflower that produces red-orange blossoms during June, July and August. Yucca, firecracker flower (Crossandra infundibuliformis) and yellow shrimp plant (Pachstachys lutea) are some other types of heat-tolerant perennials.
Flowering annuals are plants that grow from seed and go to seed during the same growing season. Annuals that prefer warm temperatures include flowering tobacco (Nicotiana alata), an annual vine that thrives in hot, southern climates. It can grow up to 6 feet in height and blossoms in shades of red, white, pink and green. Yarrow (Achillea millefolium), lantana and wax begonia (Begonia x semperflorens-cultorum) are annuals that thrive in the heat.
Shrubs can help shade and cool small areas of the landscape. Planted near a walkway or patio, shrubs can also help block the wind and provide privacy. Japanese barberry (Barberis thunbergii) is a graceful shrub that grows up to 6 feet tall and produces tiny blossoms in the spring and red berries in the late fall. Although it flourishes in hot climates, it can tolerate cold temperatures up to 30 degrees below freezing. Other shrub selections for hot climates include Texas ranger (Leucophyllum frutescens), hydrangea and juniper (Juniperus).