Gerbera daisies, and the Transvaal daisy in particular, are carefree, popular flowering plants that add color and beauty to any landscape. The over 30 species in this aster family plant are hardy in many situations: cold, salt, drought, insects, hot sun and poor soil do not deter the Gerber daisy from producing large numbers of flowers and even seeds, which often self-sow the following spring, after winter frosts kill your original plants.
History and Description
Gerber daisies, which comprise the genus Gerbera, originated in South Africa. Carolus Linneaus identified and named them in 1737. He chose the name "Gerber" to honor a friend, Dr. Traugott Gerber, a naturalist who died when he was only 33. The many species and hybridized cultivars of the Gerber daisy all have fairly large (4- to 5-inch) flowers that rise on tall stems above slightly fuzzy foliage that is normally light green. The long flower stems make the Gerber daisy a favorite in cut flower arrangements. The smallest Gerber daisy grows to only 6 inches, while larger varieties can reach almost 2 feet.
Gerber daisies are hardy in USDA climate zones 9 through 11 (Houston to Honolulu), where they can withstand temperatures as low as 20 degrees Fahrenheit. If winter temperatures do not drop below that point, the plant will often overwinter and survive into the following spring and summer. In more northerly climate zones, the Gerber daisy does well as a summer annual.
Drought and Heat Hardiness
If you live in an area where daytime summer temperatures often exceed 80 degrees Fahrenheit, plant Gerber daisies in a spot that receives partial shade, especially during the hottest part of the day. In cooler climates, plant them in full sun. Although the Gerber daisy prefers an evenly moist soil, it can withstand short periods of drought. They are not hardy when they receive too much water.
Poor Soil and Salt Hardiness
The Gerber daisy is a wildflower in its native range, so humans have not amended or enriched the soil where it chooses to grow. Your Gerber daisy will perform better if you dig some compost into its planting area and also spread mulch over the soil where it grows, but the heirloom varieties will adapt to sandy, rocky soil similar to their African homeland. The University of Florida has ranked the Gerber daisy as slightly salt tolerant.
Pest and Disease Hardiness
Gerber daisies cause deer to stay away from areas where they grow. Healthy, well cared-for Gerber daisies are less prone to insect attack than plants that receive too much or too little water, inappropriate light and other conditions. Scientists have developed cultivars that are more resistant to mites than other varieties. They are often affected by aphids, thrips and leaf miners and show little hardiness against attacks by these insects. Some cultivars are more resistant to powdery mildew than others: for example, the University of Connecticut evaluated the "Terrafame" variety and found it did not develop as much mildew as other cultivars.