Haworthia, also called zebra cactus, pearl, star window, and cushion aloe, is a large genus of small, slow-growing succulent plants that resemble mini aloe plants with rosettes of fleshy green leaves generously covered with white pearly warts or bands. Commonly kept as indoor plants, they require bright light but not all-day full sun, preferring temperatures between 70 to 95 degrees Fahrenheit. Haworthia thrives in sandy, well-draining, neutral soil that provides adequate summer moisture and relatively drier winter conditions.
|Common Name||Haworthia, zebra cactus, pearl plant, star window plant, cushion aloe|
|Plant Type||Succulent, perennial|
|Mature Size||3–5 in. tall and wide; some species can reach 20 in. tall|
|Sun Exposure||Full, partial|
|Soil Type||Sandy, well-drained|
|Hardiness Zones||9–11, USA|
Watch Now: How to Grow and Care for a Haworthia Plant
Here are the main care requirements for growing haworthia:
- Provide bright light with some shade if there's a hot afternoon sun.
- Give water when the top inch of soil dries out. Avoid overwatering, but don't let them dry out completely.
- Plant in sandy, well-draining, neutral soil; best planted in spring or early summer.
- Grow in any kind of container, but it must have ample drainage holes.
- Feed this plant fertilizer in the spring and summer months when the plant is actively growing.
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 inground. 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.
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.
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.
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.
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.
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 worked.
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.
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 Repotting Haworthia
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.
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 Problems With Haworthia
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 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.
Does haworthia need full sun?
Haworthia likes bright light and does well with direct morning sun. However, strong afternoon sun can be too much for the plant and burn its foliage.
Is haworthia easy to grow?
Haworthia is an easy plant to grow outdoors in its hardiness zones and indoors in a container. Its watering and feeding needs are simple and not time-consuming.
How fast does haworthia grow?
Haworthia is a relatively slow grower, and most species remain small.