Which Haworthia cooperi do you have?
Kew accepts 13 varieties of Haworthia cooperi, and they don’t all look alike. Leaves can be triangular or rounded, with clear tips and bristly edges. Care is the same for all of them. A few names you’ll see on labels:
- var. truncata. Kew’s living collection calls it window haworthia. It isn’t the same plant as Haworthia truncata, the “horse’s teeth” haworthia, a separate species with squarish leaves in rows.
- var. pilifera. Originally described as a species of its own, Haworthia pilifera.
- “Haworthia obtusa.” Not an accepted name for this plant. Two cooperi varieties were once filed under it, as H. obtusa var. pilifera and H. obtusa f. truncata. But Haworthia obtusa on its own now belongs to a different species, H. cymbiformis. There’s also no accepted “var. obtusa” among the 13 varieties of H. cooperi.
Light
Bright, indirect light is best. An east or west window with a few hours of gentle sun is ideal, and the RHS also suggests a north-facing one. A hot south window can be too much. It copes with less light than most succulents, but in too little the rosette stretches and loses its color.
Water
Water when the soil has dried out, then soak it and let it drain. In a well-drained mix that's roughly weekly in summer, and much less often in winter, when it needs only enough to stop the leaves shriveling. Wet soil, especially when it's cool and dim, rots the roots.
Soil & pots
Use a cactus mix, or ordinary potting soil mixed half and half with perlite, pumice or grit. Don't use sand, which clogs the gaps. A shallow pot only a little bigger than the roots keeps the mix from staying wet. Repot into fresh mix every 2–3 years.
Temperature
Normal room temperatures suit it. The RHS advises keeping haworthias above 50°F (10°C). UW–Madison says they'll tolerate the low 40s °F (about 5°C) if the soil isn't wet, but don't let it freeze.
Is Haworthia cooperi safe for pets?
Non-toxic to cats and dogs. The ASPCA lists Haworthia species as non-toxic to cats and dogs.
Propagation
Haworthia cooperi clumps up by making offsets around its base, and they're the easy way to get more plants. It can also be grown from seed, though that's mostly sold by specialist dealers.
- Unpot the clump. Many offsets already have roots and fall away from the parent.
- Break or cut off any that stay attached.
- If you tore a root or cut the stem, leave the offset to air-dry for a few days.
- Pot it in dry, gritty mix and water sparingly until it's settled.
Common problems
FAQ
Is Haworthia cooperi toxic to cats and dogs?
No. The ASPCA lists Haworthia species as non-toxic to cats and dogs.
Why are Haworthia cooperi leaves see-through?
The clear tips are leaf windows that let light into the leaf for photosynthesis. In the wild, the RHS notes, they let the plant keep working even when it's partly covered by sand.
Why is my Haworthia cooperi turning mushy?
Almost always too much water. Wet soil, especially in cool, dim conditions, rots the roots and the soft leaves collapse. Let it dry out completely, and repot in fresh, gritty mix if the roots have rotted.
Does Haworthia cooperi flower?
Yes. In spring or summer it sends up thin stems up to about 16 in (40 cm) long with small white to pinkish-white flowers.
Sources
- Haworthia cooperi Baker: Plants of the World Online, Royal Botanic Gardens, Kew
- Haworthia cooperi var. truncata (H.Jacobsen) M.B.Bayer: Plants of the World Online, Royal Botanic Gardens, Kew
- Haworthia cooperi var. pilifera (Baker) M.B.Bayer: Plants of the World Online, Royal Botanic Gardens, Kew
- Haworthia obtusa Haw.: Plants of the World Online, Royal Botanic Gardens, Kew
- Haworthia truncata Schönland: Plants of the World Online, Royal Botanic Gardens, Kew
- Haworthia cooperi (Cooper's haworthia): RHS
- Haworthia: RHS Plant Guide
- Haworthia: North Carolina Extension Gardener Plant Toolbox
- Haworthias – Super Succulents for Small Spaces: Wisconsin Horticulture, UW–Madison Extension
- Haworthia truncata: Biology Building Greenhouse, Indiana University Bloomington
- Haworthia: ASPCA Toxic and Non-Toxic Plants