Diascia

Diascia

Diascia is the orange flower

Diascia, sometimes known as Twinspur, is a newcomer to the bedding plant world. This beautiful flowering plant was virtually unheard of a few years ago, but diascia has much to offer and is easy to grow. Diascia is an excellent bedding, container or basket plant. It is also a good, low growing bedding plant to use in rock gardens and spilling over retaining walls.

Diascia came to us from South Africa, where over 70 species exist. It is a close relative to the snapdragon. Recently plant breeders began working with diascia, crossing several species to produce wonderful varieties for your garden.  Garden types of diascia are hybrids of several species.

Diascia has small, slightly oval leaves of dark green. Some varieties are upright and some produce trailing type plants. Modern varieties range from about 6 inches to a foot high and can spread to 18 inches wide.

Each tiny diascia flower is a marvel. They are small, about a half-inch or so across, and come in a wide range of colors from pastel apricots, corals, and plums, to magenta and wine red shades and the plants bloom quite freely. There is one large petal on top. There is a petal on each side; each has a projection to the back that looks like a hollow horn, or spur-, which gives diascia the common name of Twinspur. And there is a larger split petal on the bottom.

The bottom petal on the diascia flower has a small depression, shiny and yellow in most colors, right under the diascia flower’s sexual organs. It reminds one of an oval swimming pool set in the plush petal. The spurs and the pool contain nectar glands to attract pollinators. The diascia is self-infertile, and needs to have pollen from another plant to set seed.

Diascia is actually a short-lived perennial, but is often treated as an annual. The hardiness of the plants is yet to be fully determined. Plants bloom outside until Thanksgiving in zone 5 gardens, through several light frosts. When a hard freeze threatens, bring them into an unheated but above freezing place, where they go semi-dormant. They revive in the spring, put on a flush of growth and go back to flowering. Or you can simply let them perish like annuals.

Diascia seed is seldom offered for sale. If you do find some, sow the seed 6-8 weeks before your last frost indoors. It needs light to germinate so just press seeds lightly into sterile medium. Keep moist and germination should take place in about 20 days. Most diascia is started from cuttings and gardeners will find several types and many colors on sale in nurseries now.

Diascia likes cool weather and blooms best in spring and fall. Plant diascia outside after danger of frost is over, although hardy in the fall spring plants have been in a greenhouse and haven’t adapted. Plants grown in greenhouses and then set outside without a period of hardening off will be killed by frost. They will bloom all summer if conditions are cool; otherwise bloom may slow down or cease until cooler weather. In fall they will bloom for a long time, adding color after most colorful flowers are gone.

Plant diascia in sun or partial shade. While diascia will need some fertilization, especially in containers and baskets, use a light hand, as too much fertilization will produce more foliage than flowers. Use a low nitrogen fertilizer. Keep diascia moist, but don’t over water, as it quickly succumbs to wet feet. Pinching or cutting the plants back if they get lanky will encourage full plants and more bloom.

Some varieties of diascia

Several series are being marketed. ‘Sunchimes’, ‘Flying Colors’, ‘Wink’, and ‘Whisper’ series all come in several colors. Slightly older varieties include ‘Hopley’s Apricot’, ‘Rubyfields’ ‘Little Charmer’ and ‘Twinkler’.