How to Maintain a Cactus

Select an appropriate location for the cactus. Cactus plants need 12 to 18 hours of sunlight a day, but they will burn in direct sunlight. If growing the cactus outdoors, choose a location with well-drained soil.

Repot or transplant the cactus in a suitable growing medium, if necessary. Cactus plants need a coarse growing mix made of one part cactus potting mix, one part builder's sand and one part coarse gravel. If you are growing the cactus indoors, its pot must have a hole in the bottom for adequate drainage, and the space between the cactus plant and the side of the pot should be wider than ¼ inch.

Water the plant enough to make the growing medium moist but not damp. Every week, stick a pencil through the growing medium to the bottom of the pot or the full length of the pencil. If the pencil comes out dry, water the plant again. Depending on your home's humidity, a potted cactus may need weekly to monthly watering. Outdoor potted cacti may need water every two to three days.

Feed potted plants 5-10-5 plant food three times a year in the spring, summer and fall. Feed outdoor plants 10-10-10 plant food once a year in the spring. Follow the directions on the plant food container to determine how to dilute and administer the food.

Keep the plant at temperatures between 65 and 90 degrees Fahrenheit during the spring and summer growing season. If possible, keep the cactus at temperatures between 45 and 55 degrees Fahrenheit during the winter. The cactus will still thrive in warmer conditions during the dormant season, but cooler temperatures encourage flower bud growth.

Transplant a potted cactus when the space between the plant wall and the side of the pot is ¼ inch or narrower. You can roll a newspaper around the cactus to protect your hands from its spines.

Eliminate insect pests with a cotton swab dipped in rubbing alcohol.