I purchased an Euphorbia from IKEA last October. It was very robust in the beginning, but after being repotted multiple times it lost a lot of its vigour and some parts of died. I'm looking to understand what I did wrong so that I can prevent this in the future.
I didn't water this plant for the first three months I had it, from October to January. Here's a rundown of its history (pictures included below):
- October 11: I moved the plant from the pot it came in, sloppily placing it in new soil that wasn't suited for it (low drainage).
- November 20: I tried to improve the job by using a better mix (cactus mix + perlite) and repositioning the stems to make them stable.
- December 6: the smallest stem started rotting. The first symptom was a black spot, then the whole stem became soft and squishy. When I cut it and removed the root, it was much softer than the roots of the healthy stems. Only 4 stems were left.
- January 7: for the first time since I purchased it, I watered the plant.
- January 10: yet another arm rotted. This time I removed it very carefully in order to avoid damaging the other ones. It was again very soft.
- January 21: the plant seemed to have survived, so I watered the plant sparsely.
- February 12: I watered the plant again, a bit more profusely (I had recently learned that Euphorbias need water more frequently than Cactaceae).
- February 14 (today): another arm rotted, I removed it without impacting the other two, and also noticed that it had been sitting very loose in the soil, hardly any rooting had happened.
The first two times I repotted the plant I was a bit careless and probably hurt the stems or the roots it by letting the plants hit each other or hang badly.
The leading theories I have about what could've caused the rot are:
- Overwatering: while the plant has good drainage, two of the stems rotted right after being watered profusely, while when I watered the plant lightly another time, nothing happened.
- Bad handling: only explains the first two stems rotting, but the plant took a beating when I repotted it initially.
- Bad soil: the mix that the plant now sits in is very dense in perlite compared to normal soil (looks like a 3:1 ratio or higher). Maybe this is unsuited for the plant?
Picture time! Here's how the plant looked when I had just purchased it:
Here's how it looked after the repotting on November 20.
Here's the first stem that rotted and what it looked like when I inspected it (I later on found out you should never touch Euphorbias with bare hands 😅):
The arm that rotted on January 10 looked like this:
The third arm to rot, today: