How to Tell if Your Cactus is Dying: A Complete Guide to Saving Your Desert Friend

- 50% regular potting soil- 25% perlite- 25% coarse sand

Why Let Your Cacti Get Thirsty?

So a thirsty cactus isn’t necessarily a bad thing! While we as humans don’t enjoy stress, for cacti, it’s a necessary part of their lives. Some stress in the form of being a little water-deprived is a good thing, especially when they’re not experiencing enough heat to make them need lots of water.

Restricting water can help keep your cacti growing in a way they should, which is to say in a nice, compact, even way. Too much of a good thing like water can make them grow too fast, resulting in weaker bodies, fewer roots, and susceptibility to disease and rot.

So let them get a little thirsty. Indoors, you probably shouldn’t let them get as thirsty as I let mine get outdoors, though. Indoor conditions could take months, which would harm your roots and result in them dying back.

A thirsty Echinocactus viridiflorus

That Echinocactus viridiflorus is a good example of being at the point of thirsty enough to need more water, especially being out in the greenhouse. It’s a little bit wrinkled, it’s dark, and it’s a little squishy if I try poking it with gloves on. It’s not so thirsty it won’t produce flowers, which are visible as little funny buds sticking out of the side.

If you’re wondering how I know it’s thirsty, and not just supposed to look like that, you can see other examples of the plant when googling the latin name. Llifle, as ever, is a great example. Additionally, I’ve had the cactus for a couple years now, and have seen it go through thirsty/not thirsty stages. See below:

At left, before repotting, you can see that it’s nice and plump as well as green. It’s still got some ridges, but but the skin near the base of the plant looks tight and firm.

At right is it after being repotted, and needing to stay dry for a bit to let the roots heal. It’s a tiny bit thirsty in that photo, which you can tell by how it’s sort of…slouching, comapred to the one at left. If you can’t tell, you’re not alone! It’s pretty minor in photos, but I promise it’s more apparent in person.

The difference in time between the two is about 2 weeks during what was a pretty mild summer for us. The greenhouse was maxing out at 110F, with partial shade during the hottest part of the day. Many Echinocactus can very dramatically show the difference in how watered they are, and this species will shrivel down to next to nothing if kept continually dry. When I bought this cactus, it was little more than a nub in the pot!

So indoors, if you’re growing something similar, look for just that teeny bit of slouch or the slightly deflated looking appearance, and then give it some water.

Next up, a couple of my Gymnocalycium ragonesei. The cacti in focus aren’t the exact same plant, but you can see their neighbors in frame.

This particular species of Gymnocalycium has a pretty dramatic look of winter vs summer in my greenhouse conditions. You can see how flat and deflated it looks at left, which can be a pretty scary sight! It’s a much darker color, very purple-hued, which is an indication of stress. In this case, it’s very intentional stress that is healthy for them. The dry winter period keeps them from over-growing and stretching, keeping their growth tight and compact.

At right, you can see them plump and happy in summer! Hot summer temperatures and long days of sunshine are exactly what they love for growing. You can see that they are less stressed with the greener hue to them as well.

To get them to their winter state, I water less and less during the fall. When nights are getting in the 50s and 60s, I stop watering almost entirely. When they’re as deflated as the left photo, but nights are below 50, I’ll wait for a nice sunny day and then very lightly water them. That means just a little bit of a splash around the cactus, but I don’t sweat it if I get the cactus itself wet too. This keeps the roots from dessicating or getting so dry they die back, which is a risk in winter. You don’t want the cacti to have no roots left by the time spring rolls around, and they need to absorb water again to start growing!

I received this Coryphantha elephantidens cv. Titan in the beginning of fall, when it was still warm enough I was optimistic about getting it established before winter. You can see that it’s nice and green at left, when I first potted it up, but there’s some wrinkling of the outer parts of the cactus. When getting them rooted, it’s important to keep them a little dry to ensure any damage to the roots won’t rot your new cactus out!

You want to offer water on a very limited basis until it’s firmly rooted, which took longer than I expected for this guy. The roots aren’t as firm in the pot as I’d like, and it’s still a little loose when I wiggle it. As a result, it’s been watered very little, and it turned a bright red color as it got cold! My other specimen is still brilliant green, so the color change is a big indicator of how thirsty this cactus is. You can also see in the plant at right that it’s a bit more shriveled, so quite thirsty.

It can, and will, survive this just fine! I’ve started watering it now that it’s mid-March and we’re getting some warmer days, and I expect to see it really root and thrive. Coryphantha are very resilient and (usually) root easily, so longer days and warmer nights should help it along to really settle in.

First, A Word on Seasons

Most of the cacti you’ll encounter in cultivation have evolved to survive conditions that are seasonal in nature – meaning rainfall only occurs during summer or winter. Which season depends on the region, so it’s worth a bit of research into your species to figure out what they may need.

It’s worth noting that in cultivation, your cacti will never experience the same sorts of seasonal stresses they would in habitat. Indoors, your cactus will never experience the 90F+ temperatures that it probably would in habitat. It’s not going to experience nights below 50F that tell it that it’s winter, and to stop growing.

At the same time, if the cacti are near a window, they’ll still get light signals that tell it what time of year it is: the angle of the sun and duration of sunlight hours give it clues even if the temperatures don’t.

This means it’ll know what time of year it is, but won’t necesarily be stressed out about it. That doesn’t mean other things won’t be stressful, but the requirement to go dormant to survive extreme heat or cold won’t be there. Since they’re plants, not thinking beings, they’ll go dormant anyway – but it’s not as stressful.

Kind of like the difference between being stressed out about being on time to work, vs. presenting in front of a group of people at work. If your job doesn’t require any speaking in front of groups, you don’t have that stress in your life – but you’d still be worried, or stressed, about getting to work on time, right?

So if you have cacti indoors, keep in mind it’s unlikely they’ll get the same degree of stressed that my (outdoor/greenhouse) cacti do. BUT – if you’re able to, let them get a little thirsty! This is to help you see some pretty visibly thirsty cacti as examples, so you feel more comfortable letting yours go longer before watering again.

How To Tell If A Cactus Is Dead? – The Plant Enthusiast