Heat and Drought Tolerant Annuals

Since heat and drought has been an issue for gardeners for some time, this week I would like to suggest some annual plants which perform well under the hot, dry conditions that we have grown so accustomed to here in middle Georgia. While most annuals require constant moisture during the growing season for best growth and flowering, these will flower profusely with less moisture, thus saving on the old water bill. All of these will require water initially to establish a good root system but, once established, will require infrequent watering. All perform best in full sun in well-drained soil.

Portulaca or Moss Rose (Portulaca grandiflora) is a succulent often used in pots and baskets or as a ground cover. Only a few inches tall, it can tolerate the severest of droughts. A native of Brazil, flowers come in a wide array of colors—red, white, pink, orange, yellow, bicolors-single or double. It is tough and will bloom well into the fall. Portulaca will actually flower better if kept on the dry side. 

Gomphrena (Gomphrena globosa) has flower heads like clover and are available in white, pink, lavender, yellow, and red. This old-timer is a favorite of many due to its durability, its use as a cut and dried flower, and its tolerance of poor soil. The dried flower heads retain their color for long periods. Height ranges from about 9 to 24 inches, depending on variety.

Dusty miller (Senecio cineraria) is grown for its foliage rather than its flowers. Its silvery-gray leaves are often used as accents in borders, edging, and container plantings. They tend to bring out the best in presentations with red, blue, and purple hues. Heights range from 8 inches to 16 inches. Compact and bushy, they prefer hot and dry conditions. Moist sites tend to cause them to rot.

Gazania (Gazania rigens) is a heat-loving daisy. Typical daisy flowers come in bright shades of  yellow, orange, bronze, pink, white, red, and various combinations. Flower heads are 2 to 4 inches in diameter. Foliage is dark green and dandelion-like in appearance with white, fuzzy undersides. Plants range from 6 to 12 inches tall. Flowers tend to close at night and reopen the next morning.

Melampodium (Melampodium paludosum) is an excellent heat and drought tolerant annual. Small, golden yellow flowers cover the 8 to 15 inch mounding plants all summer long. They tend to reseed themselves too.

Vinca (Periwinkle) (Catharanthus roseus) is a popular drought tolerant annual which has been grown for many years and is one of the most heat tolerant of all annuals. Native to Africa, vinca has glossy green leaves with white midribs, and comes in spreading types which grow only a few inches in height to upright types which can get up to 15 inches tall. Flowers come in red, white, pink, blue, apricot, salmon, lavender, and white and often have contrasting centers or “eyes.” Like dusty miller, vinca actually prefers to stay on the dry side or root rots will often result. 

Cosmos (Cosmos bipinnatus) is an airy and delicate flower which adds a nice texture to the summer garden. Native to Mexico and sometimes called Mexican aster, cosmos is available in a wide array of colors such as yellow, white, scarlet, and pink. Its leaves are finely cut, its blossoms daisy-like and dainty. Plants reach up to 12 inches in height.

Zinnia (Zinnia species) hails from Mexico and is one of the easiest flowers to grow from seeds. They can be sown directly in the garden. Available in a wide range of colors, blooms can be single or double. Plants range from a dwarf 6 inches tall to 4 feet tall. Zinnias love the heat so much that, when the weather is cool, they don’t grow or flower very well. They make excellent cut flowers. 

Here are some additional tough annuals you gardeners may wish to add to your gardens for a beautiful show of color all summer long:

• Cleome (Spider Flower)
• Globe Amaranth
• Begonias (Fibrous or Wax)
• Nicotiana (Flowering Tobacco)

Try these heat-loving, drought tolerant annuals in your garden this summer. You’ll be glad you did!

Tim Lewis is a Georgia Green Industry Association Certified Plant Professional, gardening writer, and former Perry High School horticulture instructor. He can be reached at (478)954-1507 or timlewis1@windstream.net.