How often should I water my indoor cactus?

Written by
Benjamin Miller
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Effective care for cacti begins with an acknowledgement of their origins in the desert. Cacti can store water in their tissue, which allows them to thrive in dry spells. I have firsthand experience with this phenomenon - when I left my cactus unattended. At the same time, I took a month-long vacation, and my cactus actually flourished! In fact, letting my cactus dry out was much better for the plant than constantly keeping it moist, as it limits root rot.
Soil Moisture Testing
- Check dryness 2 inches deep before watering
- Use your finger or moisture meter for accuracy
- Bone-dry soil signals watering time
Seasonal Adjustments
- Increase summer watering to every 3 weeks
- Reduce winter watering to every 6-8 weeks
- Suspend watering below 50°F
The quality of water has a large impact on plants. Rainwater works best since it does not contain harsh minerals like those found in some surface and tap water. If you are using tap water, let it sit for 24 hours for the chlorine to evaporate. If you have hard water, you will see crusty white deposits on your planter, where salt and/or minerals are leaching over time. These minerals are harmful to plants. I have noticed that my plants are much healthier since switching to rainwater for their needs.
Light needs to go hand in hand with proper watering. Most cacti require 6 hours or more of direct sunlight per day. A south window is the best light. Keep plants in a consistent location and rotate them weekly to avoid uneven growth. Etiolation occurs in your design as a long, pale stem, indicating your plant needs more light.
Well-looked-after cacti pay their caretakers back with beautiful blooms. If you consistently care for your cacti over several years, they will eventually bloom. My oldest barrel cactus, which I have cared for for about two years, is producing blooms today. Once cacti are established and receive routine care, they can become lifelong plants.
Read the full article: 7 Essential Tips: How to Care for Cactus