Cacti Cultivation from Cuttings

Growing cacti from cuttings is easy and exciting. If one were to merely place a cutting in sand or vermiculite, and keep it lightly moist for 2 to 6 months, there is a high chance it would root. However, here's a technique for eliminating risk of failure. Lophophora varieties easily root from cuttings using the guidelines below. They can also be grafted (see Cactus Grafting Report) to a faster growing cactus, such as Trichocereus, thereby increasing growth as much as ten times. Almost any size Trichocereus cutting can be rooted. The technique for rooting a very small specimen, say one inch tall by 1/8 inch in diameter is the same as for a large three foot tall by three inch in diameter plant. If you are attempting a cutting smaller than four or five inches tall or less than three inches in diameter, it's best to use one with a tip. However, if the specimen is larger than this, no tip is needed.

Cut the specimen you want to root off the mature cactus with a sharp knife. Place it in a moderately cool and dry location, so that the base will form a dry scab at least 1/8" deep. The location must be shaded. The process usually takes 3-4 weeks. Once it has formed a scab, make two or three clean punctures with a sharp blade about one inch above the base. These openings will enable the cuttings to absorb small amounts of nourishment while it is developing roots. Then dip the entire base in rooting powder up to 1/2" deep. Establish it in a container of pure sand or vermiculite. A small container is best because this will allow the rooting medium to dry back quickly between waterings, making the danger of root rot less likely. If you wish, you can take a section without a tip and bury one half of it horizontally, following the same steps outlined above. This cutting will eventually root and form columnar heads from both ends.

It is important to use sand or vermiculite as a rooting medium. The use of soil can cause the cutting to rot before it roots. This is because soil contains high levels of bacteria. If you are attempting to root cuttings in cool weather, vermiculite (also called rock wool) is the best medium. It holds warmth, which increases biological activity. Cuttings can root within four weeks during the winter using vermiculite, provided they're placed in a warm sunny window. Most Trichocereus cacti are cold hardy to 20°F, and cuttings to 30°F. If rooting is to begin when weather is hot, sand is best because it will keep the cuttings cool. Allow the sand or vermiculite to dry back to about 1/8" above the base of the cuttings between waterings.

After four weeks, check to see if the cutting has begun rooting. This can be done by holding the cactus and container horizontally and gently pulling them apart. If rooting has not occurred, place it back in the container and check again every two weeks. It can take up to six months, or longer, for a cutting to root. So, be patient. The most important thing is to keep them warm throughout the entire process, while at the same time employing low exposure to direct sunlight.

In the winter months you can usually just place your cuttings in a sunny window. This is because the sun's rays are less intense during these months. However, in the warmer seasons it is best to monitor sunlight to two to four hours of direct light daily, depending on the light intensity. The inexperienced person is best advised to place the cuttings in direct light which has been shaded with a commercial grade shade cloth every day until rooted. This method works very well in spring and summer when it is warm enough to place them outdoors. It also works well in a warm winter greenhouse. Cuttings will often root within two weeks during spring through early fall.

Once you have determined that the cutting has rooted, reestablish it in a container or soil type suitable for ideal growing. Sand and vermiculite contain almost no soluble plant nutrients, and should be considered a rooting medium only. Most commercially available cactus soil is suitable for growing. You can produce your own high quality growing soil for pennies per gallon (see Growing Lophophora and Trichocereus Cactus from Seeds). Levels of around 7.0 ph are most desirable. However, wonderful results have been achieved with a ph of 8.0 as well. The most important factor is to have a rich loam/sand soil mix (50/50), as can be found under mountain trees of the southwest. Limestone or any other liming compound is suggested if ph levels are below 6.5. If fresh loam soil can't be found, you can compost leaves and pine needles into a naturally superior loam. Whatever loam source used, mix 33% to 50% sand for cactus planting, especially for Trichocereus.

After you've established your rooted cuttings in sandy loam soil, you need to prepare it to thrive in direct sunlight for optimum growth. This process is called "hardening off". Since you have had your plants in shade only for two to six months, they can't be exposed to long hours of direct light, or they will die of sun stroke. This is especially true if your plants become rooted in the late spring through summer. Start by locating the cuttings where they will receive only two to three hours of direct light daily (DLD) for a period of five to seven days. Then graduate them to four to five hours DLD. After a time at this level, the DLD can be increased to six or seven hours. After a couple weeks, you could allow them even more DLD. However, most cacti will grow best receiving only partial sun (four to seven hours DLD). This is especially true with Trichocereus varieties. If the plants are located in full sun (eight to twelve hours daily), they will continue to grow, but more slowly than in partial sun, and very regular waterings will be needed for faster growth and good appearance.

Once you've mastered all these steps, enjoy your well-deserved feelings of joy and pride in your accomplishment.