Prickly Pruning: thinning out a specimen prickly pear cactus

Prickly pears can get dense, becoming a mass of spiny pads instead of a sculptural element. Although not for the meek, they can be pruned. Be very careful, since the nastiest thing isn’t the spines; it’s the glochids. These are micro-spines that you often don’t see or feel right away located near the spines. Worse, some prickly pear (Opuntia) don’t have spines at all, like the notorious “Bunny Ears”

Opuntia santa-rita

Cacti, despite their rugged appearance, are heavy and fragile. They bruise easily, cut easily and the pads can crack. Since they’re full of water, they weigh a lot, although fortunately they’re lighter than water and float if the pads or branches happen to land in the pool.

Opuntia Santa-rita (pictured above) is probably the nastiest in the glochid department, although it doesn’t normally require pruning.

As the Art of War would say, the best time to do this is when the pads are young and have just grown out for the year, sometime in spring. That way, they can just be broken off with a pair of tongs before they get woody – although a very sharp knife or machete can work, too.

As the pads age, they become woody, eventually fusing into a trunk. At this stage, pruning is more difficult. You’ll need a pruning saw, protection from spines, and know how to guide falling branches by proper cutting technique. Otherwise you’ll need body armor or have enough agility to dodge falling pads. In any case, you can make things easier by removing the upper pads on a branch to be removed before making any big cuts.

Depending on the cactus species, you’ll probably get nailed by glochids while you look out for the spines. These are the sneaky part of a prickly pear’s defense system: small, hair-thin spines with a shotgun approach. Instead of a single jab from a few spines, these things attack along a broad front with tens of micro-spines.

Unless you have supernatural powers, you will get poked with a spine, even perhaps through thick fabric. Even though individual spines can often penetrate cloth, wear protective clothing and goggles – that will spare you from (most of) the glochids and protect your eyes from anything nasty.

If the cactus is really huge and treelike, call a professional. This is not a time to be in a “dumb video” competition! A professional will haul away the cuttings, too. Unless you want to start a cactus farm by rooting them…


The safest looking is Opuntia microdasys, cutely called Bunny Ears. Each “dot” on the pads is actually a nest of glochids just waiting to torment you for days once they get into your skin. Not very safe, after all! If a pad falls on your unexposed arm, you’ll see a pattern of glochids stuck to your skin. Duct tape may remove most of them, but it’s likely you’ll be tweezing them out for several days as they work their way into your skin.

In this case, the prickly pear is intermediate between the wicked yet beautiful Santa-rita and the spineless (or nearly so) Opuntia ficus-indica. Note to cactus-loving people who prefer theirs safer: Luther Burbank developed “nice” cacti just for you… well, actually for cows, but you’ll benefit, too. You can read more here – there are a lot of varieties to choose from.


The first step is to walk around the plant, determining where it can be trimmed.

Here’s the left side of the plant: low branches over the pool (potential ouch!), right branches growing into pathway

Lower limbs on the left are crushing adjacent plants, and the upper part of the plant has pads poking into each other.


Pruning your prickly pear

Once you’ve contemplated your cactus, make some light cuts. We took out the small pads between the main trunks first so that we could open up the structure and decide what to do next.

We wanted to keep as many fruit – also called tunas – as possible, since they will turn bright red in fall.

Remember to keep circling the plant as you work, checking for symmetry and to make sure you won’t leave highly visible cut from a different viewpoint.

Once the decisions were made, we took off a few more pads, thinning out conflicts at the top of the plant. The low-hanging branch over the pool went, too – an obvious choice.

Then, we headed back the major branch growing to the left from the base. This did two things: avoided future growth over the walk, and opened up views to the structure of the plant. This was a case where breaking the pads early would have worked better, since we had to make a large, visible cut.


After pruning

The cactus has two clear trunks. The pool now shows through the plant, and succulents around the base have room to develop.

The big cut is hidden by the agave at the base. With more sun, the bunny ears cactus should develop to further hide the cut. Thinning upper pads opened views beyond, to a limited extent.

We left one, higher branch over the pool where it should be well out of range of anyone not deliberately leaping out of the water. Removing it would have left the plant looking less balanced.

This cactus has gone through several cold winters, so it’s likely hardy enough to be worth the trouble of pruning.

Our cactus at home, however, is likely to freeze in a cold winter then grow back from a stump the next year – so this would be wasted effort.


What’s next

The fruit, now green, will become a very ornamental red when it ripens.

If you’re lucky enough to live somewhere warm enough for the fruit to ripen completely, you can make ice cream or gelato out of it. Read carefully online for the best method; glochids in your fingers are nothing compared to glochids in your tongue!

Next year, any pads growing from the base will be snapped off before they become large, keeping the plant in check. Over time, decisions will have to be made regarding its height and spread.

Depending on your species of prickly pear, the young pads – nopalitos – May be edible when carefully prepared and cooked. Grilled over mesquite, mixed with scrambled eggs for example…


Published by mike

Mike is a licensed landscape architect. He's also an artist, photographer and occasional chef. Luciole Design specializes in sustainable, contemporary, modern landscape design - and traditional landscape styles that fit into California's Mediterranean climate. Sacramento, California.