Why Is My Pencil Cactus Shriveling? [And Can It Be Fixed?]

Taking care of a pencil cactus, formally known as Euphorbia tirucalli, can be a painless task with the right know-how.

However, there are some common mistakes that plant owners make when caring for this beautiful Euphorbia that may cause it to shrivel.

Why is your pencil cactus shriveling? Pencil cacti store water for use later, so underwatering or overwatering can lead to shriveling. In addition, the soil should drain well, or the pencil cactus can fall victim to problems like root rot that may cause shriveling. If it has ceased to grow entirely, it might simply need a new home.

In the following, you’ll discover why your pencil cactus, or firestick plant if you prefer, is having issues, what to do about it, and other common pencil cactus troubleshooting tips.

(If you’re wondering about dropping branches, we’ll cover that here too!)

3 Reasons Why Your Pencil Cactus Is Shriveling (+ Solutions)

Luckily, there are only three troubleshooting solutions you need to get your pencil cactus back to perfect health.

If giving your plant more or less water and adjusting its soil content doesn’t do the trick, check out our other sections for possible fungus and sunlight issues.

Overwatering

Pencil cacti, like most succulents, store lots of water for later use. Because of this, overwatering your pencil cactus will cause it to droop and shrivel.

If your cactus tries to store too much water, it will be too heavy and strained.

It might look like the opposite is true, and with other types of houseplants, that usually is the case, but if your pencil cactus is yellow or droopy, overwatering is surely the cause.

As a way to double-check, you can feel the soil. If it is damp, then you know you have overhydrated your pencil cactus.

Solution

Make sure the soil is dry before giving your cactus any more water. This should be your rule of thumb moving forward, even after you have brought your pencil cactus back to health.

Remember that cacti and similar plants survive for long periods in very dry climates, like deserts.

Although a pencil cactus is not a true cactus, you should only water your pencil cactus every couple of weeks.

In fact, adding sand to your potting mixture can help the soil drain out excess moisture better, allowing your cactus to dry out.

It is best to completely repot your cactus in new, dry soil if it has been overwatered. This also prevents root rot, which can kill your cactus before you even know it’s dying.

Underwatering

While succulents in the wild prefer to store their water for later, that doesn’t mean they only get tiny sips of water when it does rain.

In nature, the rain will fall for a few minutes or many hours, giving plants time to soak up the moisture they need.

If you are worried that your dry-climate plant needs as little water as possible, you may be prone to underwatering. If you notice crispy brown tips or wrinkles, your pencil cactus is thirsty!

Solution

Water your pencil cactus every other week, making sure to give it a full dose of water. Make sure the soil is damp all around.

You may need to water it weekly if it has started to get wrinkles, and then reduce your watering routine to every other week. 

Just be sure to keep an eye out for any yellowing, a symptom of overwatering. You may need to reverse your efforts if that happens.

Wrong Type of Soil

The wrong type of soil for pencil cacti leads to drainage issues, as we’ve briefly mentioned.

If the soil is too dense, any water you add will not drain, and your plant will suffer from root rot or try to absorb too much moisture.

Solution

Make sure your potting mixture has at least one-quarter of sand. You can also add rocks or gravel to the bottom of the soil, which will create a natural filtration system for excess moisture.

Other Pencil Cactus Issues To Watch For

In addition to shriveling, pencil cacti also can be prone to fungi. Sometimes called “gray warts,” this fungal issue is called phomopsis. It can affect many different kinds of cacti.

You can cut the fungus off with a clean knife, and use a sulfur mixture to kill any lingering bacteria.

You can boil or use a lighter on your blade to sterilize it before cutting your pencil cactus and after each cut to avoid spreading the problem.

Once you cut the plant, do not touch the open area as this can be harmful to your skin. It is best to use disposable gloves for the entire process.

One more note I want to mention: pencil cacti are extremely harmful to dogs. Please make sure your furry friend can’t reach your pencil cactus if you have both at home!

Related Questions: Other Pencil Cactus Concerns 

Why Is My Pencil Cactus Dropping Branches?

Overwatering causes your pencil cactus to store too much water, making its branches heavy. They will start to turn yellow, then brown, then finally gray before falling off completely.

If you catch this symptom in the yellow stage, you can try repotting it with dry, sandy soil to give your pencil cactus its best chance to heal.

Why Is My Pencil Cactus Not Growing?

We have discussed water, soil, and fungus, but sunlight is one of the most obvious and sometimes forgotten aspects of cactus care!

If your pencil cactus seems to be growing slowly or has stunted completely, make sure it is in direct sunlight.

Sometimes pencil cacti will grow on one side and not the other if they are placed by a window. You can rotate your pencil cactus weekly to ensure maximum growth all around.

Conclusion

Pencil cacti are beautiful and easy to care for with the right know-how. Make sure your soil is dry before watering your cactus, and keep an eye out for signs of thirst. 

Give your soil the proper ingredients for filtration, and make sure your pencil cactus gets plenty of sunlight, and you should be on your way to pencil cactus bliss!