Monk's Hood

Scientific Name: Astrophytum ornatum (De Candolle) Weber ex Britt. Rose
Synonym: Astrophytum glabrescens, Astrophytum ornatum var. virens , Astrophytum ornatum var. spirale , Astrophytum virens, Echinocactus ornatus
Family: Cactaceae

Recommended Temperature Zone:
Sunset®: 11-13,18-21
USDA: 9b-10

Frost Tolerance: Hardy to 20° F (-6°C)

Heat Tolerance: Excellent in Phoenix in summer

Sun Exposure: Light shade

Origin: Mexico (Querétaro, Hidalgo)

Growth Habits: Solitary columnar cactus, up to 4 feet tall (1.2 m), 6 inches in diameter (15 cm); usually 8 ribs; 1 central spine; 5 to 10 radials

Watering Needs: Moderate water in summer. Allow the soil to dry before watering again. Do not water in winter.

Propagation: Seeds that germinate rapidly. Some cultivars are grafted. They take up to 6 years to bloom.

The Astrophytum ornatum is the largest and one of the easiest to grow of the Astrophytums. It has 5 to 8 ribs (generally 8) and areoles have 5 to 11 brownish yellow spines, over 1 inch long (2.5 cm).

Blooming Habits:
The Astrophytum ornatum blooms in summer. The 2.5 inch wide flowers (6 cm) are pale yellow and scented. It needs to be 6 inches tall to bloom (15 cm). This might take six years or more depending on the length of its growing period in your local conditions.

Culture:
This Astrophytum is the easiest to grow and also the fastest. It responds well to half strength fertilizer in summer. To make sure that the fertilizer doesn't encourage growth instead of blossom, it might be better to wait until the flower buds start forming before using fertilizer.