What is Acalypha?

Acalypha is a very large genus of herbs and shrubs in the Euphorbiaceae family. They are commonly known as three-seeded mercuries or copperleaves. Several species are grown horticulturally, particularly Acalypha hispida, the chenille plant. This species has bright red or purple flowers that look like cat's tails. Chenille plants are grown as subtropical or tropical plants or as houseplants in cooler climates.

There is one note of caution about this type of Acalypha — all parts of the plant can be poisonous to animals if ingested. Also, the sap of the plant can cause a severe dermatitis to humans. This may not be a good plant to grow if there are small children in the house.

This species of Acalypha was originally found on islands in the East Indies. The plant has become naturalized in many parts of the world, however. It can grow to a height of 6 to 12 ft (1.8 to 3.7 m) and be 3 to 6 ft (0.9 to 1.8 m) wide. If grown as a houseplant, it should be kept heavily pruned.

The oval evergreen leaves are 4 to 8 in (10 to 20 cm) in length and half as wide with pointed tips. The most attractive part of the chenille plant is their flowers. Male and female flowers are borne on separate plants. The bright red or purple female flowers can grow to be up to 20 in (51 cm) long and 2 in (5 cm) wide. They droop and appear fluffy, like the tail of a cat. If conditions are favorable, the plants will bloom all year long.

The chenille plant will grow in full sun or partial shade, but the plants flower best in full sun. They need a lot of humidity and to be watered frequently during the summers. They have a poor tolerance of salt in the soil. For garden plantings, this type of Acalypha should be planted 3 to 5 ft (0.9 to 1.5 m) apart. The plants are not hardy to frost, so they can only be grown outside in tropical and subtropical areas.

Often, the chenille plant is grown as a container plant on a porch or patio and then brought indoors over the winter. It makes a lovely hanging basket with the flowers spilling over the sides. Chenille plants are also grown specifically as houseplants. If there is air conditioning, the plants need to be misted regularly to keep them humid.

Ideal household temperatures are at least 70° F (21.1° C) during the day and 60° to 65° F (15.6° to 18.3° C) at night. The soil should be kept moist. The plants should be fertilized every month, so they will bloom continuously. Inside, the plants also prefer direct sun, although they will grow in indirect bright light. Older plants should be pruned in the spring, leaving 8 to 12 in (20 to 30 cm) intact.

Another option to have vigorously growing chenille plants indoors is to propagate the plants by cuttings in the summer. This will ensure a constant supply of new plants if done yearly. Experts advise using cuttings that have a heel on them.