Cactus identification and care instructions

(Question)

Hi,

I was wondering whether you would be able to tell me what sort of cactus this is, and more importantly how I care for it. In addition to watering and sun instructions, I would be interested in knowing whether I need to change the soil from time to time or other care needs of which I need to be aware.

Thank you.

(Answer)

Thank you for writing about your very healthy-looking Euphorbia  trigona, so-named for this succulent’s clearly defined, three-sided ascending spires.

This is generally an easy-going plant to care for:

  1. Your plant loves bright sunlight, but “indirect sunlight”, to prevent scalding of the tender tissues;
  2. Succulents also love well-drained planting medium, and so advise you to ensure that the current medium is still suitable, otherwise, re-pot up using a mixture for cacti, available at a nursery;
  3. Ensure that the pot has an ample saucer underneath, to receive all run-off from regular, cleansing, watering;
  4. Never let the roots sit in water: roots need to dry out thoroughly between watering, or the leaves will yellow;
  5. Your plant can grow quite tall, so if necessary, consider supplying firm, but thin stakes to stabilize, over the years.

Enjoy your Euphorbia!