I purchased a cactus from IKEA. It appears to be Euphorbia Pentagona or Euphorbia Enopla. The date on its pot makes me think it was repotted on December 14 2016, 4 days before I purchased it. On the day of purchase, the soil was moist.
Since purchase, the cactus has been sitting close to a south-facing window, however the weather conditions in the Netherlands rarely lead to full-sun exposure in the winter months. Indoor temperatures have fluctuated between 14°C (57°F) and 18°C (64°F), while outdoor temperatures have ranged between -1°C (30°F) and 7°C (45°F).
One month after purchase, the top of the plant's stems show signs of bright green growth. My untrained eye is unable to distinguish whether this is etiolation.
The guides I read say that most cacti need a period of dormancy between November and March where they need water only once every one or two months, and no fertiliser.
Somewhat contradictory, guides also say that cacti prefer to be fed during spurs of active growth, such as the one I think my cactus is experiencing.
My questions:
- Is this cactus etiolating (maybe due to the change in conditions), or growing?
- Depending on the answer to the previous question, and keeping in mind that it's still winter, should I fertilise my cactus?
- If I need to fertilise, is this 4-4-6 NPK cactus fertiliser solution that I purchased appropriate?
Pictures:
I've added before and after pictures for comparison below. You can notice the growth I'm referring to especially at the top of the bigger stem on the left:
December 18 2016:
January 14 2017: