Light
Cacti like as much bright indirect light as you can provide. Introduce a cactus plant to direct sunlight gradually to prevent sunburn. The ideal location for a small cactus pot is on the windowsill of a south-facing window.

Water
Allow the soil of a cactus to dry out before watering, then water deeply and thoroughly. Never allow a Cactus to sit in water. A cactus requires more water in the spring, summer, and early fall when it is growing than in the winter. Over-watering is the main reason cactus plants die.

Fertilizer
Use a fertilizer low in nitrogen and high in potassium at 1 4 the recommended strength. The type of fertilizer used for tomatoes works well. Fertilize monthly in the late spring and summer when a cactus is actively growing. Do not fertilize the rest of the year.

Temperature
An indoor cactus plant likes temperatures between 16°-27°C

Humidity
This plant comes from the desert and does well in very low humidity.

Flowering
After a 3 month resting period and under proper conditions, a cactus plant may bloom during the late fall and winter.

Soil
Use a fast-draining, porous, sandy soil to prevent over-watering and root-rot.

Pot Size
Vertical cactus plants need pots that have a diameter 1 2 the height of the plant. Horizontal cactus plants need pots that have a diameter 5cm larger than width of the plant. If a cactus plant starts to topple, place it in a deeper pot.

Resting Period
A cactus needs less (or even not at all) water and cooler temperatures in the winter when it is resting.