Green Stuff in my seedling


I recently moved to CO so I am still learning the environment differences coming from Texas.

I have four seedlings sprouted. Yesterday, I notice that one had a lime green spot on the Rapid Rooter I used to sprout. Today it looks a little bigger than a small spot.

Any idea what it is ? How to treat ? Will it affect other sprouts ?




I don’t know about CO, I live in OR and when I use rooting cubes, I sometimes get that moss growing on the surface. I usually just spray it with a 3% hydrogen peroxide solution to take care of it. I don’t know if the moss is harmful or not.

When I don’t over water, less chance of moss.


I get it also. So far hasn’t been an issue.


That makes sense!! A couple of my clones I bought at a clone shop here had similar green on top and they are flourishing now.



I am really good to let them dry before watering. I just watered this morning hence the reason they look so wet.


Excellent…here in the Northwest, moss is everywhere! My yard has a 6" thick carpet of moss under all of the giant fir trees.


My perlite on the surface in the coco turns pretty green also. Looks like algae to me.


Algae is a better term this stuff…thanks @New2this.


Thanks everyone I feel a lot better knowing the girls are ok.

We didnt have much moss/algae in Texas since it was so freaking hot.


It’s definitely algae. Can happen if you water your plants a little too frequently or humidity is a little too high. Happens to most of us lol