‘How Often Should I Water My Cactus?’ & Other Questions All Plant Killers Wonder, Answered

You’ve been told it’s one of the easiest plants to care for. But now, two months into Plant Parenthood, you’re convinced the internet lies! That spiky little cactus is starting to look a little shriveled and sad, and while that may be a 2020 mood in and of itself, you really need a win. How often should I water my cactus? Is that sagging a sign of root rot? What even is root rot? Your mind’s spinning as you try to troubleshoot ways to keep that plant alive. But there’s good news: You don’t have to go it alone. With a little guidance, your cactus can thrive, which is why we’re answering some of the biggest questions we all have about caring for cacti, so you can have one less thing to stress about right now.

Spring through fall tends to be a cactus’s growing season, when it needs more water. Even then, you typically only need to water it once a month, writes Seana Monley Rodriguez, founder of Tierra Sol Studio in North Carolina. If you’re tempted to water more often, just make sure the soil has dried out completely before you water it again, and always pour the water directly onto the sand or soil, rather than onto the plant itself. From October through January, you can get away with watering your plants every other month, since cacti go dormant then.

Browning, root rot and abnormally plump spines are all warning signs that you’re loving your plant just a little too much, according to cactus-care site Cactusway.com. Root rot is exactly what it sounds like—a disease that decays the plant from the bottom up, and if left untreated, will kill it. If your cactus is becoming wobbly, there’s a good sign it has root rot—and the case may be severe if its base is brown or yellow. (Did I just describe your plant baby? Take action: Remove the cactus from its planter, look for any brown or black roots, cut them off and replant it.)

In general, when watering, you want to soak the soil so that water runs from the planter’s drainage holes. No holes in your planter? Use this guide from Tierra Sol to get a sense of how much to use. A six-inch cactus, for example, will only need about 1 to 2 tablespoons of water a month, whereas a super-trendy micro cactus may only need a few drops a month.

Look for a sunny spot with indirect light to perch your cactus and avoid any areas near air conditioning units or radiators, which can be too intense for the little guy. (Psst: If you can’t find that ideal indirect-lighting scenario, no worries: The folks at Tierra Sol say your plant will still be OK if it lives in a medium- to low-light spot.)

The aforementioned signs of root rot—wobbling and discoloration—are big ones. If you notice soft spots in the cactus’s stem, or there’s a foul smell coming from the plant, the outlook isn’t too good for your little guy.

The soft spots can be a sign of a fungal infection. Cutting off the infection portion (as long as it isn’t, like, 90 percent of the plant) and spraying the plant with a fungicide may save it.

A week-old-garbage-left-in-the-hot-sun smell, however, you aren’t so likely to recover from. It may be best to put that plant to rest and evaluate what went wrong (overwatering is a common culprit, but here are some other considerations), so you can do better next time.