Cactus

(Question)

Dear Master Gardeners:
A question re the cactus in attached photo. I was given it last year. It is only about 4 inches tall. When I
got it, it was a single “stem” but in early spring it decided to branch out and created 15 or so small offshoots all on the ridges on the stem.
I don’t know what to expect next. Will these remain attached, and grow, totally changing the shape of the plant? Or are they likely to drop off and become separate plants? Thank you.

(Answer)

Cactus plants are a family of succulents that store their sustaining resources such as water and nutrients in their stems. There are approximately 150 genera of cacti and they are often grouped according to their growth habits. The photo illustrates that your cactus is a columnar cactus. Columnar cacti consist of thick or thin upright branches that branch from the base or sides of the main trunk. There are a considerable number of cacti  that fall into this category. Without additional information it is difficult to correctly identify the genus and species.

In general, a column cactus is a large, thorny cactus with one or more upright, ribbed, columns. There usually are five to nine prominent ribs running up the sides of most column cacti. Occasionally, plants are found with the ribs spiralling around the column rather than growing vertically. The ribs are rounded and the brown thorns, or spines, grow along the ribs.  Some column cacti send out branches from each rib. These branches will continue to grow and when the branches become too heavy they can break off and may be repotted.

You may wish to refer to the following Gardening Guide: Growing Cacti and other Succulents for additional information of caring for cacti.