A rain daisy, scientific name Dimorphotheca pluvialis, is one of ten species of tender annual flowers in the genus Dimorphotheca, which is part of the Asteraceae , or daisy, family. This fast-growing flower is native to South Africa and Namibia, but will grow in other hot, dry areas of the world. It may be used in landscaping and grows equally well in container gardens. It is a fairly disease-resistant plant and easy to care for. Manufacturing industries in Europe use the rain daisy in several types of industrial products.
The rain daisy is also known as cape marigold, African moon flower, weather prophet, and white African daisy. It grows in U.S. Department of Agriculture Hardiness Zones 9-11, which means that the lowest temperature this plant tolerates is 20° Fahrenheit (-6.6° Celsius). Rain daisy prefers full, direct sunlight and handles heat well. It grows in any type of soil, but prefers a well-draining sandy soil with a mildly acidic to mildly alkaline pH level. Rain daisies require regular watering, but dislikes being soggy and overwatered.
In their native habitats, rain daisies are pollinated by swarms of small horseflies. Rain daisies grow from 6 to 12 inches (15-30 cm) in height and have a spread of about 12 inches (30 cm). Seeds sown in fall result in profuse, vivid white flowers with brown-to-blue central discs during late spring to mid-summer. Flowers are about 2 inches (5 cm) across and the narrow, leathery, light green foliage is about 2-1/2 inches (7 cm) long. Rain daisy flowers close at night, during rain, and on cloudy days.
Gardeners often use masses of rain daisies in rock gardens, flower beds, and in container gardens. The rain daisy works well in xeriscaping, or landscaping requiring little supplemental water, because of its high tolerance to heat and drought. The seeds can be started indoors prior to the last frost and transplanted or can be sewn directly into the ground during the fall. Once the flower has been introduced into a location, it does a good job of self seeding during the following years. It is important that gardeners keep weeds from overtaking the rain daisy as it does not compete with other plants very well.
This low-maintenance plant seldom requires fertilizer or additional care. Its only real pest is the guinea fowl. These birds like to eat the young, tender plants. If insects do infest the plant, they can be handled by using an insecticidal soap approved for use on flowering plants.
Fields of rain daisies are commercially grown in northern Europe for seed. Seeds are either packaged and sold or the oil is extracted from them. Manufacturing businesses use it to make industrial foam, coatings, and plastics.