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What Is a Star Cactus?
The star cactus (Astrophytum asterias) is a spineless cactus in the Cactaceae family. Considered an endangered species by the United States Fish and Wildlife Service, the star cactus is native to North America and can be found in the Mexican states of Nuevo León and Tamaulipas, as well as parts of the United States, including the lower Rio Grande Valley of Texas. Other common names for this cactus include sea urchin cactus, sand dollar cactus, and star peyote.
At maturity, this low-maintenance cactus plant stands approximately three inches tall and six inches wide. Its ribbed structure gives the cactus its star-like shape with eight triangular sections surrounding woolly areoles. Grayish-brown in color, the star cactus is covered in white dots. The plant has yellow flowers with orange centers that typically bloom between the months of March and May.
6 Tips for Planting a Star Cactus
To grow a star cactus from seed, harvest seeds from an existing plant’s dried flowers. Follow these tips for planting a star cactus:
- Soak the star cactus seeds before planting. Soak the seeds for a few hours to give them a better chance at rooting.
- Plant star cactus seeds quickly. The seeds from the plant’s dried flowers are fragile and do not last long. When growing star cacti from seeds, plant them quickly after harvesting beneath a very thin layer of cactus potting mix.
- Enclose the grow pot with a plastic cover. This covering helps the plant retain moisture.
- Slowly acclimate the seedlings to light. When the seedlings appear, slowly increase the amount of direct sunlight the seeds receive for several weeks. This will prevent the plant tissues from experiencing sun damage.
- Repot star cactus at the start of the growing season. Astrophytums should be repotted around April to replenish the soil and give the plant room to fully develop.
- Water the seedlings sparingly. These plants are sensitive, so only water them when the soil has dried out.
How to Grow and Care for a Star Cactus
While the star cactus is a low-maintenance plant, it does require specific care to reach full potential:
- Plant the star cactus in well-draining, sandy potting soil. The star cactus grows best in well-draining, sandy potting soil that allows water to drain. Avoid soils that are rich and retain moisture, which will cause the cactus to perish.
- Place the star cactus in direct sunlight. The star cactus requires full sun. Place it in direct sunlight outdoors. If you keep your cactus indoors, position it near a window that provides direct sunlight.
- Water the star cactus sparingly. In order to avoid root rot, ensure that star cactus roots do not sit in water. During the growing season, water your cactus thoroughly once a month. Less water is required during the winter months.
- Fertilize the star cactus during its growing season. The star cactus benefits from a mix of balanced fertilizer and water.
- Keep your cactus in a warm location. This cactus thrives in temperatures above 70 degrees Fahrenheit. Ensure that the plant’s space is not very humid, as it thrives in dry conditions.
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