How to Make a Cactus Flower Blossom

Shield the plant from artificial light during the evening and night, beginning in September. Cacti often are associated with long hot days, but desert conditions also include cold, dark nights. In most home gardens, cacti grow indoors in pots or outside on a lighted patio. Excessive ambient light prevents the cactus from blooming. Cover the plant to exclude light during the evening and night hours, removing the cover every morning. Limit daylight hours until the flower buds are well-developed.

Expose the cactus to temperatures below 50 degrees Fahrenheit beginning in the fall. Protect the cactus from high winds and freezing temperatures. Cactus blooms are triggered by a combination of cool night temperatures and short daylight hours. Night temperatures between 40 and 55 degrees Fahrenheit are ideal.

Allow the soil to dry out before watering, and provide only minimal water. Most garden grown cacti receive too much water.

Fertilize cactus in the late spring or early summer. Use a low nitrogen formula designed for cactus, and follow package directions. Withhold fertilizer during the remainder of the year. Cacti need very little fertilizer. Too much nitrogen triggers vegetative growth and inhibits flowering.