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Why Do Cactus Explode – The Impact Of Overwatering

Plants are an interesting form of life and come in all different shapes and sizes, with plenty of different needs to match their wide visual variety. Cacti are particularly odd: succulent, spiky, and even sometimes a bit fuzzy. But something abnormal for even the oddest type of plant is when your cactus bursts at the seams. Why do cacti explode?

Your cactus may “explode” when it has been overwatered. Usually, there are warning signs, such as a slight split in the stem, but continual overwatering will lead to a ruptured plant.

Continue reading to learn other reasons this may happen and how you can prevent it from happening.

How does a cactus explode?

A cactus explodes not all at once with a “bang” and is instead a slower process that starts with a heavy watering hand. A small split will begin to develop between a “seam” on the cacti, and it may look small and unassuming, but assuredly, it’s on its way to busting completely.

Cacti are succulent plants, so they have evolved in dry, drought-like conditions, allowing them to retain water for these long periods of drought. Providing too much water is like over-filling a water balloon: at some point, the balloon can no longer support the pressure the water is exerting, and the only way to relieve this pressure is by bursting.

Unfortunately, your plant will have a gaping wound after this has happened, making it more likely to get infections or pests. It’s best to try again with a new plant and learn how to avoid turning your cactus into the world’s most anticlimatic bomb.

What happens if you overwater a cactus?

Overwatering a cactus can cause more issues than just explosions: overwatering can lead to root rot which can spread to the rest of your plant, causing it to slowly wither and turn to mush in the pot. Other overwatering complications can make your plant more susceptible to pests and diseases, both of which can be a headache to get rid of.

Going a bit heavy on the water once is not likely to kill or cause your plant to explode, though it’s important to let your plant dry out fully if it has gotten too much water. In the case of repeated over-watering, you can always gently remove the plant or dig into the pot and check out the roots.

Rotted roots can be removed using clean, sharp scissors, and your cactus can be repotted into fresh, dry soil. This procedure may be enough to stop the rot from taking over the rest of your plant. If you find that most of the roots (more than 50%) are rotted, it is unlikely your plant will make a recovery, but you can always try anyways; after all, plants are full of surprises.

Other symptoms of an overwatered cactus are wilting, yellowing, and a “mushy” appearance of the stems. If your cactus has gotten to the point of textural changes, it is too late to save it. Propagate any healthy offshoots quickly to keep your plant’s legacy alive, and vow to do better next time.

Overly wet soils can also attract fungus gnats and other pests that may not directly harm your plant but are a pest nonetheless. If you see little gnats flying around your soil, this is an indicator to cut back on the watering and maybe even remove the plant from the soil entirely to check its roots. Returning to fresh soil and a cleaned, dry pot can eliminate these pests and give you a reason to check its roots.

How to prevent cacti from exploding

Not often is forgetfulness or neglect a positive when caring for something, but in the case of the cactus, it is actually more beneficial to be a bit forgetful with the watering than to smother it with H2O. Not only does this prevent your cactus from developing splits that will result in full-on gaping wounds, but you’re also less likely to encounter pests like fungus gnats, and you don’t have to be concerned about root rot either.

Generally, cacti and other succulents can handle drying out fully through the soil before they want a nice soak. The amount of time this takes varies based on location, whether indoors or outdoors, potting mix, and the amount of light your plant is getting.

Under optimal conditions indoors, your succulent can probably handle getting watered once or twice a month, maybe an additional time if it is outdoors under bright, direct light.

It’s safer to assume your plant doesn’t need water. Some signs that your cacti are ready for water are slight wrinkles in the skin and, of course, dry soil.

Another way you can tell if it’s time to water is by getting to know the weight of the plant when it’s freshly watered and when it’s thoroughly dried out. This way, all you have to do is pick up your pot, and you can gauge how much water is in the soil based on the wait.

If you have doubts, wait a few extra days before checking in again. Your cactus will thank you for doing this by not spontaneously rotting or bursting.

Final thoughts

While it’s a serious issue to have an exploded cactus, it’s pretty avoidable. Remember to err on the side of caution when watering succulents, and remember they would rather dry out than be too wet. Not only is it easier to not water as frequently, but you will avoid a slew of issues from root rot to explosions!