Haworthia is a genus of about 150 species of small succulent plants. Like Aloe, Gasteria, and Astroloba, they are members of the family Asphodelaceae. Most species are endemic to South Africa, with some extending into neighboring countries, in Swaziland, Namibia, and Mozambique. Many species of Haworthia have been moved into new separate genera, Haworthiopsis and Tulista.
Haworthias can grow solitary or clump-forming with usually stemless rosettes of fleshy leaves that vary in size, shape, texture, and color. Even two plants growing side by side in the same collection can have different coloration or markings. Flowers are small, generally white, and borne in slender inflorescences, usually erect and unbranched.
The generic name "Haworthia" honors the British botanist and entomologist Adrian Hardy Haworth.
Growing Conditions for Haworthia
Haworthias are usually grown in containers as indoor plants, but you can bring them outdoors in summer. They are also grown outdoors in areas where frosts are infrequent and brief.
Light
Although some species can grow in full sun, most Haworthias prefer more sheltered spots and thrive in partial shade. In habitat, they tend to grow under bushes and rock overhangs. This adaptation makes them well-suited to lower light conditions in homes and offices. Place the potted plants in a bright area with some protection from the hottest rays of the day. White, yellow, or red-tinged leaves usually indicate that your Haworthia receives too much sunlight. Deep shade tends to weaken the plant over time. Haworthias grow very well under artificial lights. If they have spent the winter indoors, gradually move your plants outdoors into the bright sun to prevent sunburn.
Soil
Haworthias do not like their roots to remain wet for prolonged periods, so their soil should be well-drained. In habitat, they are found growing in sandy soils in rocky areas. Use a commercial potting mix for succulents, or make your own.
Temperature
Haworthias like warmer temperatures in the summer but prefer cooler temperatures in the winter. The natural cooler temperatures in an unheated room during the winter are perfect. However, Haworthias do not like being too cold. They do best at temperatures between 75°F and 90°F (24°C and 32°C). Some species can survive a light frost for a short period, but it is best not to take chances. Most Haworthias are cold-hardy down to USDA hardiness zone 10a, with a minimum temperature of 30°F (-1.1°C).
Pot Size
Shallow pots are generally better than deep ones, but some Haworthias have large, thick roots that need a deeper pot. Be sure that your container has at least one drain hole.
General Care for Haworthia
Haworthias are one of the easiest succulents to care for, making them popular houseplants. They are great plants for beginners.
Watering
These succulents tolerate underwatering, but overwatering can cause rot. When the growth is most active in spring and fall, water Haworthias thoroughly, then wait until the top of the soil dries out before watering again. Water your plants less during winter, when their growth slows significantly. During the hottest summer months, when Haworthias are mostly dormant, water them just enough to keep the leaves from shriveling. Never allow water to sit on the rosette. If you use saucers, empty any standing water promptly.
Fertilizing
Haworthias are small, slow-growing succulents and do not require much fertilizer. For optimum growth, fertilizing is a good idea. Feed only with a dilute fertilizer and only during the active growing season. Avoid summer fertilizing as Haworthias are in a 6- to 8-week rest period. Do not fertilize newly potted plants for the first year.
Repotting
These succulents are generally slow-growing and can stay in the same pot for years. Repot Haworthias into fresh soil every two to three years to keep your plants healthy and happy. Many Haworthias freely offset and form clusters much larger than the individual plant. When the cluster has outgrown its pot, repot your Haworthia in spring or fall. Clean any dead or shriveled leaves, and move the plant into a larger pot with a fresh soil mix only if the cluster covers the entire soil surface. Repotting time is also the time to take offsets for propagation.
How to Propagate Haworthia
Vegetative propagation, especially by offsets, is the quickest and most common method of propagating Haworthias. However, these succulents can also be propagated by leaves and seeds.
Offsets
Besides being the easiest method for propagating Haworthias, offset propagation helps maintain a good plant shape. Most Haworthias will make offsets sooner or later. Remove the offsets once they have begun to develop roots. Allow the offsets to dry out for one or two days, and plant them in a small pot with a well-draining soil mix. Put the pot in a warm, bright spot and water when the soil is dry.
Leaves
Plants that never or rarely offset can be propagated from leaf cuttings. First, remove a healthy leaf from the rosette along with a slight bit of attached stem tissue. Allow the leaf to callous for several days, then place it in a container with a well-draining soil mix. Keep the container in a bright place, out of direct sunlight, and water when the top of the soil is dry. Often, one or more new plants will slowly form from the leaf. Roots will appear in weeks, but rosettes usually take longer to develop.
Seeds
Sow the seeds in spring or fall in a well-draining soil mix. Keep the soil moist until germination, which usually takes one to two weeks. Transplant seedlings into individual pots after the first or second year.
Pests and Diseases of Haworthia
Pests
Haworthias are generally free of most pests that attack succulents. The one exception is mealybugs. They can be a common problem, but it is easily resolved by physical removal or standard houseplant insecticides. When soil is kept too moist, fungus gnats can be another problem.
Diseases
Constantly wet soil can also lead to root rot, a common problem with Haworthias. Symptoms of a rotted root include the stoppage of growth, reduction in plant or leaf size, or leaf shriveling. Occasionally, such root rots can spread into the stem, leading to the plant's death.
Toxicity of Haworthia
Haworthia species are generally non-toxic to humans and animals.
Links
- Back to genus Haworthia
- Succupedia: Browse succulents by Scientific Name, Common Name, Genus, Family, USDA Hardiness Zone, Origin, or cacti by Genus