Algae on sphagnum

[Liz]

I've got plants in sphagnum outside under shade cloth, and there's now algae growing on the top of the sphagnum. Is it harmless, or do I need to do anything to get rid of it? If so, what?
Thanks, Liz

[LJA]

Liz, the algae itself is totally harmless. However, the fact that it's growing on the sphagnum means that the sphagnum may be starting to break down, plus the algae is going to keep air from reaching the roots. It's not a life or death emergency, but you might think about repotting pretty soon.

[Liz]

Breaking down already? Really? These are newly potted plants... I assumed it had something to do with being under the shade cloth, like moss on the north side of trees or something. If it's just on the top, and isn't growing down into the moss, what about picking it off and adding a little sphagnum if it gets too thin?

Thanks, lja ... you are always so quick with a good answer!

[Jmoney]

I was about to say exactly what Louis just said.

I usually notice algae after 4-6 months in sphag, and by my standards repotting time isn't far away. I grow on windowsills but use clay pots, so the smaller 3" pots might get water every 2-3 days at first. (Probably hastening the breakdown of the sphag, but I use it for those quick-dry quick-rewet cycles).

If it's freshly repotted, like within a month or two, it might be a function of the plants being outside and exposed to spores and such. Algae is usually quite harmless, unless it grows into thick mats that choke off air exchange. It does tend to *smell* though, especially indoors while watering.

[OrchidTraci]

Originally posted by lja
Liz, the algae itself is totally harmless. However, the fact that it's growing on the sphagnum means that the sphagnum may be starting to break down, plus the algae is going to keep air from reaching the roots. It's not a life or death emergency, but you might think about repotting pretty soon.

What about the green mossy stuff that some plants seem to have on purpose, you know, the stuff you can find in patches in your lawn or growing on a rock. What is that for, moisture- humidity? And if it is useful, how to you get it (other than scraping it off the dirt in your yard.)

[Jmoney]

While some plants naturally grow in mosses (i.e. phrag caudatum), I think those mosses have more "substance" and allow a firmer foothold for roots than the stuff we see on rocks and the north sides of trees. I don't think the latter moss will do much to help or harm plants. The key to air exchange at the roots lies in the media and the watering practice. Maximal air exchange occurs with a light, airy media, maybe some holes in the pots, and frequent watering to bring air down into the pot (which of course requires the fluffy media so that the plant can dry out between watering).

[MonkeyThrowPoop]

i have moss spores and cant grow them at all.


moss likes: coolness 40-75
high humidity and constantly moist.80-90%humidity
shade or inderect sun.


moss doesnt like fertilizer and needs pure water.

you can suppliment moss by watering with rinsed rice water.

good luck

[LJA]

Traci, a real easy way to propagate moss if you have some growing in the yard is to gather a handful (by scraping it off, or whatever) and throwing it into a blender with a big container of plain yogurt. Blend on "high" until you get green goop. Use a paint brush and paint the goop onto the outside of clay pots that you've previously soaked. Keep that moist for a couple weeks by misting it. In no time at all, the moss will start growing on the pot.

We used to use this method when we built ponds for people and they wanted the "instant old" look. Paint the rocks with the yogurt mix, keep them misted, and in a couple weeks, voila: mossy rocks.

And like Monkey said, keep cool, moist, and no direct sun.

Finally, deliberately putting thick mats of moss on top of the media for orchids serves absolutely no purpose other than "beautification." It will also keep the media wetter for a longer amount of time, and may prevent sufficient air from reaching the roots. This practice is commonly used on orchids sold at florist shops.

(BTW, you'll often see a thin layer of moss and even a few ferns growing naturally in the pots of lower-light orchids from real orchid vendors / growers. The spores come in on the bark or are floating around inthe air, and a few taking hold is unavoidable. No harm done, just means it'll be time to repot soon since the outer layers of the medium have begun to break down...)

[Liz]

But, Louis, in my case, my plants are growing in clay pots with holes and styrofoam peanuts at the bottom. Shouldn't that let sufficient air get to the roots?

[PAGrower]

Finally, deliberately putting thick mats of moss on top of the media for orchids serves absolutely no purpose other than "beautification."

Someone gave me an orchid planter as a gift that had an oncidium and a phal growing in that thick moss. The oncidium is still in there and actually seems to like it, but the phal got taken out almost immediately because the leaves were starting to wrinkle.

I've never had algae on a plant but I have had little mushrooms growing in some of my pots. I just let them die off of their own accord because I didn't want to touch them and end up spreading the spores around.