Spots and discoloration on your cactus houseplant may be from improper watering.

Watering from the bottom is preferred as splashing water on the cactus may cause unsightly markings. Place your cactus pot in a basin of water and allow the water to wick upwards through the drainage hole into the soil of the plant for ten minutes or so and then check that water has adequately moistened the potting mixture before removing. Allow the water to drain for a few minutes once your cactus is lifted from the basin; do not let the plant stand in a wet dish. It is essential that you avoid over-watering so do not give water if the soil is still moist. Keep humidity below 30% to the extent possible.

In the fall and winter, desert cacti experience a non-active growth period and it is important to adjust your care to preserve the health of your cactus. Water less frequently and always before noon so that all the water can be absorbed or evaporate during daylight. Water only enough to keep the plant from shriveling and err on the side of too little water.

For more on cactus cultural requirements,please see our Guide to Cacti Indoors.

For tips on a variety of gardening topics, see our range of Plant and Garden Guides.

- Courtesy of NYBG Plant Information Service