African Violets and Gesneriads: Top of my soil is green, 1 by critterologist

critterologist wrote:
I get algae on the top of my seedling pots all the time, because I purposely keep them fairly moist. As long as it's just a little bit, I don't worry much about it. I do sterilize the soil, which helps for a while (long enough for seeds to germinate etc), but some amount of algae is pretty inevitable on my veggie & flower flats in the basement. Watering with hydrogen peroxide (2 Tbsp per gallon) helps a little, and I haven't tried adding lysol to the water yet (can't stand the smell).

I get a little algae on my violet pots sometimes too, especially the leaf pots which have more extra soil around the roots (and thus stay wet longer after watering) but since I let them go dry pretty frequently (especially on the surface), it never seems to get too thick or to threaten to choke the plants or roots in any way. Admittedly, it doesn't look pretty!

If the green algae is just on part of the soil surface, I just ignore it. If it starts forming a thin mat, as in the pots in the front left of this photo, I scrape it off the surface, and if I let the pots go a little more dry afterwards, that generally knocks it back down.