Cacti are popular for a variety of reasons, including their unique look, easy care, and long life. Many flower beautifully in the spring or summer most are beautiful in both shape and coloration. There are two type of cactus plants: desert and forest. The desert varieties are the ones most commonly seen in garden stores and many are hardy in all types of weather.
Growing Conditions for Cactus Plants
Cacti require full sunlight in almost all cases. Only a select few are shade varieties. Many cactus plants sold in the U.S. are tolerant of cold weather and even snowy winters, but be sure that your choices of plant are able to withstand whatever elements they may be exposed to in your area and growing conditions. Nearly all small and medium sized cacti are good potted varieties.
Most cacti require a relatively long hot growing season, so they will need to have at least six months of 70+ degree Fahrenheit weather continually in order to thrive. Most areas of the U.S. can provide that outdoors and all indoor plants will have these criteria met.
Soils for cacti should be fast-draining, so regular potting mix will probably not work well. Special cactus-specific potting soils are available or you can add sand to standard potting soil in a 1:4 ratio to cut the soil and make it thinner.
How to Plant Cactus Plants
Most cactus plants are purchased already growing, so planting is just a matter of digging a hole and putting the cactus in it or adding it to a suitable pot. Some things are different from normal transplanting procedures, however.
When planting outdoors, make sure the soil is correct for the plant then dig a hole about double the size of the pot the cactus is currently in and about half, again, as deep. Then put the plant in the soil, filling in and tamping down. Follow the directions that came with the cactus, of course. Usually, you will wait 2-3 weeks before watering in order to let the roots set and the cactus acclimate to its new home.
Potting cactus is easy, but most people over-pot their cacti. Cactus plants grow very slowly, so pots that are just large enough to contain the plant are all that’s needed. Indoor cacti take to replanting well, so replanting the cactus every 3-4 years is not going to hurt it. Wait 2-3 weeks before watering.
Care of Cactus Plants
Once settled in, caring for a cactus is not difficult. A lot of light, the right temperature ranges, and water. Most people under water their cactus plants. In the spring and early summer, when the cactus is doing most of its growing, the soil should be kept damp below the surface. So at about an inch down from the top, the soil should always be damp. For outdoor cacti, this usually means watering two or three times a week and for indoor it means a twice weekly watering.
Fertilizers should be specialized for cacti. Most standard fertilizers will short cacti on nutrients. Another thing to be careful about is watering after the peak season. In the late summer and winter, watering should be tapered off to almost none. In the winter, if the plant is outside and weather is harsh, no watering is generally necessary while indoor plants will likely require at least one watering a week because of the warmth of the indoors.
Cactus Plants Pests and Diseases
The most common diseases with cacti are due to over watering. In the fall and winter, cactus plants are susceptible to rot from over watering. Damp soils and the natural conserved dormancy of the cactus will cause outer edges, especially those close to the water source, to rot. This can usually be remedied by ceasing the water and cutting away the rotted portions.
Cacti can also have problems with mealy bugs, aphids, and mites in some areas. There are sprays for these.
Cactus Plant Varieties for Yards
The most common yard varieties are the echinopsis, with their bright red flowers, and astropythum, which have beautiful yellow flowers in the spring. Many other regional varieties are also commonly grown outdoors.
Cactus Plant Varieties for Containers
Container cacti are the most common type grown in the U.S. Probably the most common is the aloe vera. Also, flowering varieties and ornamental species from around the world are popular choices. Here is more information on varieties of cacti by Clemson University.