How to Water a Pencil Cactus

The site says “During the spring and summer allow the top 50% of the soil to dry out before watering. In the fall & winter water once a month.” Exactly how much water do you give once a month? 1 cup? 1 quart? And how often do you water in the spring and summer? I inherited a very large one from a beloved friend that passed, and I’ve inadvertently killed 2/3rd’s of it. I only have one stalk left and I desperately want to keep it alive! It’s the one thing I have left to remember her by. Thank you Judy for any help you can give!


Hi Stephanie,

It sounds like you have over- watered which is really the only way to kill a Pencil Cactus. These plants are drought resistant. When in doubt, DO NOT WATER!

Here is what you need to do:

Remove the plant from the pot and get rid of all of the wet soil especially on the roots. Cut off any roots that appear “mushy” and dead.

Allow the plant to sit out BARE ROOT for 24 hours. Repot in fresh dry soil especially designed for succulent or cactus plants. The pot should be only an inch or two larger than the root ball and must have drip holes in the bottom. If the pot is too large, the soil stays wet too long, and the roots die.

Place in bright indirect light and do not water for about a month. When you water, water well enough so that the water comes out the drip holes in the bottom of the pot. Do not allow the plant to sit in this excess water. If the plant is not in bright indirect or the room is quite cool, do not water for 6 weeks.

In the spring and summer, how frequently you water depends on the light and temperature in the room. In a hot, bright room, it could be every 3 weeks. In an air-conditioned room that only gets medium light, it could be every 4-5 weeks.

If the plant is in a deep pot and you can’t easily check to see how wet the soil is at the very bottom of the pot, you should probably invest in a water meter. You read about these in the Glossary of the website.

Here’s what a healthy Pencil Cactus looks like and a link to my care tips for growing a Pencil cactus.


Learn how to identify a Pencil Cactus plant