Haworthias are a popular type of succulent to keep as a houseplant. These plants come in a variety of eye-catching forms, are easy to grow, and can be quickly propagated to make new plants. In warmer parts of the U.S., haworthias can be left outdoors year-round. In colder regions, can be kept as houseplants that will do well even when neglected. Follow this guide to discover how you can grow your own healthy, thriving haworthias.
I. Appearance and CharacteristicsÂ
Haworthia is a large genus of small succulent plants endemic to Southern Africa (Mozambique, Namibia, Lesotho, Eswatini and South Africa).
Like aloes and gasteria they are members of the subfamily Asphodeloideae and they generally resemble miniature aloes, except in their flowers, which are distinctive in appearance. They are popular garden and container plants.
These plants were discovered by Henri Auguste Duval (1777-1814) in 1809. The genus name is derived from Adrian Hardy Haworth’s (1767-1833) name, a botanist and avid succulent collector.
Haworthias are small succulent plants, forming rosettes of leaves from 3 cm (1.2 in) to exceptionally 30 cm (12 in) in diameter, depending on the species. These rosettes are usually stemless but in some species stems reach up to 50 cm (20 in). The inflorescences of some species may exceed 40 cm (16 in) in height. The plants can grow solitary or can be clump-forming. Many species have firm, tough, fleshy leaves, usually dark green in color, whereas others are softer and contain leaf windows with translucent panels through which sunlight can reach internal photosynthetic tissues.
Their flowers are small, and generally white. Though they are very similar between species, flowers from the species in section Hexangulares generally have green striations and those from other species often have brown lines in the flowers. However, their leaves show wide variations even within one species. Additionally, when the plants are stressed (e.g. deprived of water), their colors can change to reds and purples. Depriving them of nitrogen generally results in paler leaves.
Almost all Haworthia species are naturally adapted for semi-shade conditions (in habitat they tend to grow under bushes or rock overhangs) and they are therefore healthiest in shade or semi-shade. Some species like Haworthia pumila and Haworthia truncata can be adapted to tolerate full-sun however.
All Haworthia species favour extremely well-drained soil (in habitat they tend to grow in poor sands, in rocky areas). Watering depends on the species (winter or summer rainfall) but most of the common species are tolerant of a variety of watering routines. Over-watering can cause the roots to rot. Rarer species may have more specific requirements. All haworthias are sensitive to frost, and they are rated as winter hardy to USDA zone 10.
Haworthia species reproduce both through seed and through budding, or offsets. Certain species or clones may be more successful or rapid in offset production, and these pups are easily removed to yield new plants once a substantial root system has developed on the offshoot. Less reliably, the plants may also be propagated through leaf cuttings, and in some instances, through tissue culture.
II. Types of Hawthoria
There are more than 100 species of haworthia, but their classification can be complex. The main difference among the common species is the size of the leaves and the orientation of the white markings on the leaves. The best advice is to buy the most attractive variety that appeals to you based on leaf form and markings, as they all have similar cultural requirements. Some popular species include:
- H. margaritifera (pearl plant): This clumping variety has white speckles on its tentacle-like leaves.
- H. fasciata: Features thick dark green leaves with horizontal white stripes and is sometimes known as the zebra haworthia.
- H. bolus: Stemless with fleshy leaves that form a rosette, it’s called the spiderweb haworthia due to the fine white hairs growing along the edges of its leaves. This species does best in full sun.
- H. attenuate Features white wart-like pearls on the top and the bottom of its long pointed green leaves.
III. How to Grow and Care
Sunlight
Haworthia species like bright light but not exceptionally strong direct sunlight. They make attractive small potted houseplants and can be moved outdoors for the summer months.
In their native environment, they are often found in the slight shade of a rock or other object. In regions without frost, they are sometimes grown outdoors in ground. They can tolerate direct morning sun, but harsh afternoon rays can burn foliage. White, red, or yellow leaves usually signify too much sun. But if a plant isn’t getting enough light, its green color will fade. Indoors, haworthias do best near an east- or west-facing window.
Temperature and Humidity
Haworthia species like warm temperatures between 70 and 95 degrees Fahrenheit in the summer and cool temperatures down to 50 degrees Fahrenheit in the winter. They can be damaged when temperatures fall to 40 degrees Fahrenheit and lower. Humidity isn’t an issue for this plant. It requires good ventilation, especially at night when it takes in carbon dioxide for photosynthesis.
Watering
Water whenever the top inch of soil has dried out during spring and summer, but ensure the soil is never waterlogged. Reduce watering to just enough in the fall and winter to keep the leaves plump. Never allow water to collect in the rosette; this can lead to rot.
Soil
These plants like sandy or gravelly soil with excellent drainage. Use a cactus potting mix or another fast-draining potting soil for container plants. Mix the soil with perlite, aquarium gravel, or pumice to improve soil drainage.
Fertilizing
Follow label instructions to fertilize haworthia during the spring and summer growing seasons with a cactus fertilizer. Don’t feed during the fall and winter.
Pollination
Since pollinators can’t reach your indoor plants, you must hand-pollinate haworthia using a pair of fine, sterilized tweezers and a headband magnifier. Pollinate from noon to late afternoon. When the upper parts of the petals curl outwards, a flower is fully opened.
Pluck the stamen from the male parent with pollen on the tip (anthers). Rub the pollen from the anthers onto the stigma or the female part of the flower—the sticky bulb you see in the center of flowers where the pollen lands and starts the fertilization process. A stigma is usually fertile for pollination about two days after opening.
Keep a pollinated plant in a cool, shaded place, so the pollen doesn’t dry out. If the ovary becomes green and swollen, the pollination works.
Propagation
A cost-effective way to propagate haworthia plants is via its offsets, the tiny pups, or new plants growing from the base of a parent plant. Propagation via offsets prevents the parent plant from becoming overcrowded. A convenient time to propagate haworthia is when it has overgrown its container and needs to be repotted. Hawthoria is best propagated via the division of its offsets. Here’s how:
- What You’ll Need: Use a sharp knife or snips to cut as close to the parent stem as possible and include as many roots as possible.
- Allow the Offsets to Dry: Place the pups on a dry, flat tray. Place it in a dark, dry spot with air circulation. Wait at least 24 hours before repotting.
- Potting: Plant the offsets in a small pot using the same kind of potting soil as the parent plant. Lay the roots on top of the soil and gently cover the roots with a layer of soil. Wait a few days before watering.
Potting and RepottingÂ
Haworthias are small plants (usually growing no more than 5 inches tall). They are relatively slow-growing. They are often produced in small clusters in wide, shallow dishes. But they also can be planted individually in containers. A small unglazed clay container is ideal because it will allow excess soil moisture to escape through its walls. Drainage holes in the container are essential for good drainage.
Over time, clusters will naturally enlarge as the parent plant sends out offsets. A group will typically outgrow its container every three to five years. If a larger container isn’t necessary, repot the plant with fresh soil. Repotting should occur in the spring to early summer. Use a wider container with a new potting mix or split the cluster into separate containers.
Pests and Diseases
Common Pests
Haworthias are free of most pests, with one common exception: mealybugs. These small, oval insects that suck the juice out of the foliage can be controlled by simple physical removal or insecticidal spray. Also, if the soil is too moist, you might have problems with fungus gnats. Remedying the over-wet condition is often all you need to do to combat this problem.
Common ProblemsÂ
Haworthias are hardy plants if they are grown in their ideal conditions. Generally easy to grow, the same best practices that yield healthy aloe and echeveria plants will also produce beautiful haworthia plants. But issues with their environment can result in a few common problems.
Drooping Leaves
Drooping or shriveling leaves can be the result of underwatering. But more commonly, they are a sign of overwatering and subsequent root rot. Soggy soil can kill the roots. When water does not drain readily, the water continually fills soil air pores, and the roots cannot “breathe” or exchange gases. The roots will eventually die from a lack of oxygen
Ensure you are watering only when the soil has dried out, and never leave your plant in waterlogged soil.
Leaves Turning Yellow
Yellow leaves on haworthia are often a result of too much sun, as are red or white leaves. Move your plant to a slightly shadier spot—but not full shade—and that might solve the problem.
III. Uses and BenefitsÂ
Due to their compact size and striking appearance, Haworthias are primarily used as ornamental plants. They are well-suited for indoor terrariums, dish gardens, and as desktop plants. Their ease of care also makes them a popular choice for beginners.
