Is there a difference between cacti and succulents? Cacti are fleshy plants that store water—therefore, all cacti are succulents. On the other hand, in order for a succulent plant to be considered a cactus, the plant must have areoles. Areoles are small, round, cushion-like mounds of flesh where spines, hair, leaves, flowers, etc. grow from the cactus. Generally speaking, basic care for both cacti and succulents is essentially the same. Individual plant preferences may vary slightly from one genus to the next.
Light
Cacti like as much bright, indirect light as you can provide. Introduce a cactus 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 completely dry out between watering. In spring and summer water deeply and thoroughly; however, in winter give just enough to barely wet the soil. 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. Overwatering is the main reason cacti die, especially during winter months. Misting is not a great method of watering cactus or succulents; it is often better to keep the foliage dry if possible.
Fertilizer
Use a fertilizer that is low in nitrogen and higher in phosphorus and potassium at 1/4 the recommended strength. The type of fertilizer used for tomatoes works well. Fertilize monthly in late spring and summer when the cactus is actively growing. Do not fertilize the rest of the year.
Temperature/Humidity
An indoor cactus likes temperatures between 60°-80°F and does well in very low humidity.
Flowering
Under the proper conditions, a cactus may flower after a 3-month resting period during late fall and winter. Most succulents flower at least once each year, but timing depends on type of plant.
Pests
Even plants full of thorns get pests! These plants are susceptible to mealy bug, scale, spider mite, and aphid problems. Scale are usually found around the thorns and can be scraped off with a small toothbrush or cotton swab dipped in rubbing alcohol. Spray with a mild insecticidal soap to get rid of any other pests.
Diseases
Overwatering leads to crown, stem, and root rot.
Soil
Use a fast-draining, porous, sandy soil to prevent over-watering and root-rot. You can purchase special cactus/ succulent soil at a nursery or make your own by adding pumice or other coarse material to regular houseplant soil.
Pot Size
Vertical cacti need pots that have a diameter of about 1/2 the height of the plant. Horizontal cacti need pots that have a diameter 2 inches larger than the width of the plant. If the plant starts to topple, place it in a deeper pot. In general, shallow containers are better than very deep ones. Drainage holes are essential!
Propagation
A cactus can be propagated by seeds, plant division, and plant cuttings. Plant cuttings are definitely the easiest method.
Resting Period
A cactus needs less water and cooler temperatures in the winter when it is resting (and no fertilizer).
FAQs
1. I LOVE CACTI, BUT EVERY ONE I BUY GETS BROWN AND MUSHY AT THE BASE AND DIES.
You’re overwatering your cactus. Cacti are great indoor plants only if you are careful not to give them too much water and locate them in bright light! The soil must be allowed to dry out. In cool weather, a cactus can survive on a tablespoon of water per month.
2. CAN I MOVE MY INDOOR CACTUS OUTSIDE IN THE SUMMER?
Your cactus will love it. Be careful to introduce it to direct sunlight gradually or it will get an ugly sunburn. Bring your cactus inside before temperatures go below 55 degrees, but check it for insects first or gently spray it with a mild insect soap solution.
3. HOW CAN I START A NEW CACTUS FROM MY OLD CACTUS?
Propagating most cacti is quite simple. Break off a small piece from an area on the old cactus plant that’s not easily visible. Dip the cut end into Rooting Hormone. Plant the cactus piece in a small pot of porous, fast-draining soil. Cacti are very slow growing plants, so it may take quite some time before you have a substantial new plant.
4. I’M AFRAID I’M GOING TO OVERWATER MY CACTUS. IS THERE ANY WAY TO TELL WHEN A CACTUS NEEDS WATER?
There are several ways to tell if a cactus needs water. When cactus soil is wet, it holds together; when it’s dry, it becomes powdery and falls apart. You can try sticking your finger into the top of the pot as far down as it will go to test moisture level. You can also stick your finger into the bottom drip holes and to check for moisture. My favorite way is to look at the cactus. If it has become soft, supple, or even a little shriveled, it is definitely time to water.
5. MY CACTUS NEVER BLOOMS. IS THERE ANYTHING I CAN DO?
Cacti, like gardenias, need temperature fluctuations in order to bloom. There should be at least a 20-25 degree difference between daytime and nighttime temperatures. Feed a cactus with a fertilizer low in nitrogen (since it encourages green growth) and higher in phosphorus and potassium (since these encourage flowering). Putting a cactus outside in the summer encourages it to flower, but be careful of the direct sun.