How to Prune Cacti and Succulents
For controlling unruly desert flora, use care and make the kindest cut.
By Cathy Babcock
We usually think of pruning in terms of trees, but any plant, including our native desert flora, can become overgrown or incur breakage. The ‘why’ of pruning a cactus or succulent is the same as for a tree: to remove dead, broken or diseased pieces or branches; to reshape the plant; and for safety reasons, such as clearing a pathway for passersby. The best time to prune cacti and succulents is in late spring or in the fall when it is still warm and dry but not unbearably hot. In addition to gloves, necessary tools will generally be pruners, loppers and saws. Ensure that tools are sharp and clean for best results. Call a cactus care professional if you suspect that disease may be a factor or if the plant is too large and overwhelming to tackle yourself.
Many homeowners tend to overwater their plants, including cacti, which can cause faster-than-normal growth. Cholla and prickly pear aren’t always neat growers and can easily become unruly in a landscape setting. Prune these by making cuts at joints. Take special care with the prickly pear, as they are covered with tiny hairlike spines called glochids that can be extremely uncomfortable if they end up under your skin. Larger cactus plants, such as organ pipe (Stenocereus thurberi) and senita (Pachycereus schottii), can be cut back as far as needed by pruning the stems with a saw wherever needed. Give the stem a clean cut, bleaching your implements before and after each cut. No additional treatment is necessary.
Mature agaves vary greatly in height and width. Never “pineapple” an agave (removing live leaves all the way around the circumference of the plant leaving only a tuft at the top), as this renders the plant susceptible to sunburn, insects, disease and rot. If you must prune dead leaves, eliminate only the bottom layer. Removing the pointed tips is also not recommended, mostly for aesthetic reasons. Again, plan ahead and don’t plant in close proximity to a walkway. If need be, reduce the size of clumping agaves by removing the bottom layer of pups—the offsets or small plants that grow around the “mother” plant. Generally, once agaves bloom they will soon die, and there is no reason to cut off the stalk. Nolina (Nolinaceae spp.) and desert spoon (Dasylirion wheeleri) should also never be pineappled, although they frequently are.
The same rules for removing dead agave leaves also apply to aloes. Spent flower stalks on most species will pull right out when the stalk dries up. If you don’t wish to wait, cut the stalk down as far as possible without damaging the plant. Aloes come in many growth forms, including clumping and shrubby types. A healthy aloe can quickly become overgrown; shrubby aloes can topple over if they get too tall and lanky. Reduce the size by following individual rosette stems back as far as you can before cutting. Often, the bottom rosettes will pull out easily.
Some of the larger yucca species, most notably Joshua trees, tend to put out offshoots and develop branches that droop downward. Offshoots can be cut out and, although difficult, can be re-rooted. Cut drooping branches back to a main stem or joint. Many yuccas retain their old leaves, which remain as a sheath on the trunk as the plant grows. You may often prefer the look of a clean trunk and, indeed, many nurseries sell these larger specimens already cleaned. While the leaves protect the trunk from mechanical damage and sunburn, removing them does not cause harm. As such, trimming is best done at the end of the summer to avoid sunburn on the trunk.