Time for an update.
Sea Mac recommended feeding them, and I tried to follow this advice but I don’t know what I did wrong. I gave them Grow Big Liquid Plant Food from Foxfarm (6-4-4). I mostly fed them foliarly through misting. Unfortunately they didn’t respond very well, and after a couple of weeks the leaves started to die. They even dropped some. Here are some partially-dead leaves today:

I was actually afraid they’d all die. I interrupted the feeding and stopped misting them alltogether. I moved from misting 1–2 times per day to watering them once per week. They actually liked this and are now producing pretty new leaves and existing leaves are growing big. I’ll try adding some plant food in the water soon.


The small plant has also started to grow, albeit slowly. I think it will make it.
And here’s a processed shot of the mid-sized plant:
