Astrophytum capricorne senilis
Botanical Name — Astrophytum capricorne senilis
Common Name — Goat's Horn Cactus
Plant Family — Cactaceae
Astrophytum capricorne senilis is known for its twisted thorns that resemble ram’s horns. It is native to the rocky slopes of Sierra de Parras in Coahuila, Mexico. Spherical in structure while young, it will grow taller and more cylindrical with age. These plants are so densely wrapped in soft bristles that they are often mistaken for bundles of dry grass in the wild. Beautiful, showy flowers bloom at the crown in yellow, sometimes with a red center.
- These cacti prefer lots of sun, at least five hours of direct sun daily. They can tolerate a little shade, but the more sun the better.
- Indoors, a south facing window is ideal. Outdoors, give them a place where they will get plenty of sun exposure.
- Astrophytum like it hot! Above 70 ºF in the summer is preferred. As these plants are native to mountainous areas of Central America, they are accustomed to seasonal cool weather.
- During the winter they prefer cooler temperatures, between 50 and 60 ºF. If grown outdoors, move them to a sunny windowsill inside if temperatures regularly drop below 50 ºF.
- Astrophytum prefer to stay on the dry side. In the summer water them only when the soil has dried out entirely. Always err on the side of underwatering. They are built to withstand drought, and overwatering is one of the quickest ways to kill them.
- During the winter water very infrequently. Maybe even once a month or month and a half! It’s safe to cut back on watering entirely. This will encourage flowering during the spring!
- Astrophytum are native to rocky, mountain slopes and desert climate. They prefer a gritty, well-draining soil mix. A cactus mix would work fine. You can amend it with sand or fine pumice up to 50% to improve grittiness and drainage.
- Cacti will produce one or more flowers between spring and summer. Look for wide, 6-10 cm in diameter flowers. They are typically yellow, but sometimes emerge pink or orange with a red centre.
- Astrophytum plants flower once they’ve matured. This can take up to six years. Exposing your cactus to drought while it is dormant during the winter will encourage blooming during the growing season.
- Typically, Astrophytum do not require fertilization. You can feed them during the active growing season to give them a boost or refresh their soil. Apply a balanced fertilizer diluted at half strength, once a month. Never fertilize in winter.
- Astrophytum are typically propagated by seed. Seeds are fragile and have a fairly short shelf life. Be gentle with them and sow quickly after harvesting to improve chances of germination.
- Very occasionally these plants will produce offsets which can be separated and grown independently.
- Astrophytums are not especially susceptible to pests or diseases. Keep an eye out for common pests such as aphids, mealy bugs, and scale.
- Root rot can be a common issue in the instance of overwatering.
Maintenance (pruning, legginess, repotting)
- Astrophytum plants are very low maintenance. They prefer to be pot bound. Repot them once every one to two years. Early spring is the best time to repot, when they are just waking from their dormancy.
- Astrophytum are not known to be toxic to humans or pets.