My mammillaria is turning green
Hey so over the last few weeks the stones in my pot have started turning green but it wasn’t effecting the plant so I thought it was fine, recently I noticed my plants white little fully spines have started turning green or disappearing and I’m not sure if this is natural or if this is starting to kill my plant. At first I thought it might be the stones but the cacti next to it (which is the same species) has started turning green too and it doesn’t have any stones. Is this something I should worry about? or is it normal?
12” pot with drainage
Last watered 2 years ago
1
Best Answer
I think that green stuff is algae, it grows from the substrate being wet and the sunlight hitting it. It’s not harmful, unless you’re using a reservoir because it uses the oxygen in the water reservoir… but I would be careful you’re not getting your cactus wet when watering and your substrate isn’t overly damp. You can treat it with with hydrogen peroxide or something with algaecide (for example I have physan 20), but you can also just leave it.