Cactus with skinny legs

(Question)

Hi,

Purchaced this cactus 5 years ago at the spring show at Alan Gardens. It was in bloom (hasn’t flowered since) and they were lovely, full cylinders. Now they’re looking a little withered at the base.
I water well once a month, rotate pot 1/4 turn then too. Never fertilized. The tops don’t seem to have grown much in diameter, but have gotten a little longer. Are they sick?
Thanks!

(Answer)

Succulents and Cacti make interesting low maintenance houseplants as there is a vast array to choose from.  For maintenance and care, you will find a link below to the Garden Guide created by the Toronto Master Gardeners which should give you some general pointers.

Growing Cacti and Other Succulents: A Toronto Master Gardeners Guide

With regards to your particular plant, I would suggest there may be a few issues you may need to address –

  1. If your plant has been in the same pot for 5 years, it is very likely pot-bound.  This can be easily determined by looking at the pot drainage hole to see if roots are protruding – if yes, then your plant is likely pot-bound.  If you don’t see roots there, gently ease the plant out of the pot to observe how much root growth is inside. If roots are overly abundant with little soil, again it’s a pot-bound situation.  In this instance, go up one pot size to give the plant a bit more space making sure the new pot has a good drainage hole.  In your picture, it looks like it is in a terracotta pot and this is a good choice for your bigger pot too.
  2. On the topic of re-potting, the soil your plant is in (if it is the same for 5 years), then most of the nutrients will have been used already by the plant.  It may be time for some new soil even if the plant is not pot-bound.  Lift the plant out of the pot and brush away some of the soil from around the roots and discard.  Replace this soil with new soil specifically formulated for succulents and cacti.
  3. You do not mention how much light your plant gets but generally cacti like a brighter environment.  I would also suggest rotating it more than once a month so all parts of the plant get exposed to sunlight.
  4. Watering cacti and succulents takes a bit of “trial and error” but I think yours may be on the dry side as it is “withering”, so watering a bit more frequently may be warranted – maybe once every 3 weeks instead of monthly to see if that makes a difference.
  5. As with all plants, yours needs a source of food in order to thrive.  I would suggest fertilizing it every 2 weeks from spring, through summer and into very early fall.  Visit your local nursery or garden centre to purchase a fertilizer formulated specifically for cacti and follow the instructions carefully as it is easy to over feed these plants and do more harm than good.

One more thing to note.  As your cactus looks like it is quite prickly, wear a good pair of protective gloves when handling it, re-potting or changing the soil.

Hope this information is helpful.  Good luck.

19/02/23