Starfish flowers - stapelias - are easy to grow - stapelias from South Africa

Flower & Garden Magazine, Oct-Nov, 1984 by Lily Fry

STARFISH FLOWERS--Stapelias--are easy to grow

The stapelias, from the dry regions of South Africa, are a most bizarre group of plants.

No one who sees the starfish flower, Stapelia gigantea, ever forgets it. Its 13- to 18-inch blossom is among the largest in the world--yellow, five-pointed, with petals marked with crimson lines. Its buds look like inflated balloons, opening slowly one petal at a time. Also unforgettable is its odor, giving rise to the common name "carrion flower,' which applies to several stapelias.

Few bees and hardly any butterflies are present as pollinators in the native region of these plants, but there are plenty of flies. Presumably it was nature's scheme to attract flies for pollination of flowers by the odor. The insect mistakes the flower for a piece of rotting animal carcass on which, habitually, it lays its eggs so that larvae hatching from them have something to feed on. In justice to the flowers, the carrion odor is not noticeable more than a few feet away, and it is of short duration.

Another stapelia with similar odor but a smaller plant is "toad cactus,' Stapelia variegata, with stubby finger-like stems, more clustering growth habit, and greenish yellow wrinkled flowers heavily dotted with maroon.

Both of these in their arid native regions became adapted against drought. The soft spines or tubercles that grow along the angled stems mark the positions of primitive leaves lost long ago to reduce the need for moisture.

Give stapelias sandy soil and good drainage. A suitable mix is four parts good potting soil to one part builder's sand. Keep new plants watered well while they are actively growing (spring to late summer), then allow to dry down one inch deep. In fall/winter keep them on the dry side, watering only when stems soften, signaling a need for water.

Although they grow in full sun in the wild, in captivity they seem to do best in a more subdued light. An eastern exposure with morning sun is good during their growth period; and when they are dormant a south window suits them. They summer well outdoors if kept out of hottest midday sun.

To propagate stapelia, merely twist off stems at joints and set them into a rooting medium. A good rooting mix is equal parts moist peat and perlite, with a half part of sand added to improve anchorage. Stand the cutting upright in the mix but don't cover it so deeply as to block air circulation. Keep the medium on the dry side and at 70 degrees or more. Anytime during the growing season is a good time to propagate.

When roots are a half-inch long, put cutting into a 3-inch pot containing the sand and soil mix. Keep it in the shade and fairly dry until established-- about two weeks. Expect blooms in about two years.

After a year, transfer the plant to a 4-inch pot; the next time to a 6-inch; then 8. If you lack space for big pots these plants will thrive for a long time in a 6-inch pot. Keep old stems pruned off; feed the plant occasionally with a low nitrogen fertilizer such as 5-10-5. Blooms occur on stems of the previous summer.

Both of these stapelias as well as most others grown as house plants do well in a wide range of temperature. In winter, 60 degrees will suit them, and they can take it as low as 45 without harm. In the growing season, above 60 degrees is needed for blooms, even to 100 degrees or more where air circulates freely.

Mealybugs and spider mites can sometimes be troublesome. Malathion spray applied by label directions, two doses a week apart, will quickly get rid of mealybugs; and for spider mites, use Kelthane.

If stems and roots should rot, the cause is usually overwatering. Take a cutting from a healthy portion and start a new plant.

Yellowing stems indicate a bit too much water, or not enough drying time between waterings. If stems show a brownish red tint they are getting too much sun.

In greenhouses stapelias will thrive when placed in at least 30 to 40 per cent shade and kept where there is no change of being overwatered. Give them the hottest and dryest spot in it, provided fresh air is available. In winter I have grown these plants as low as 45 degrees without harm, by keeping them quite dry. They start into growth when temperature starts to rise in spring.

A number of house plant specialists in succulents offer these and other fascinating varieties. For a list of mail order sources, send stamped, self-addressed envelope with request for BR-249, Flower and Garden Magazine, 4251 Pennsylvania Ave., Kansas City, Mo. 64111.

Photo: With a diameter of 13 inches or more, the flower on Stapelia gigantea ranks among the largest individual blossoms known.

Photo: A smaller flower but similar in shape, color, and odor occurs on the Stapelia variegata, sometimes called "toad