Green moss growing in orchid pots?
 

Hey guys,

I've just noticed this weird green moss growing in the pots of my three orchids. These include one phal, one dendrobium nobile and one lime-green phal lookalike with thick blossoms. I've watered all three about every ten days, every other time with some fertilizer, letting the water drain out through a hole in the bottom of the glass pot.

I think the phal lookalike came with green moss growing in the topsoil when I bought it from the local flower shop. I've just now repotted it with all fresh soil. I also repotted the phal and rinsed off the roots and pot thoroughly. The dendrobium has such dense roots though, and I'm not sure I can easily uproot it without doing massive damage to it.

Any suggestions on what this may be, how to combat it and prevent it happening again?

I like using clear pots for growing phals but, with clear pots, the media will very often develop some green algae. I don't find that it harms the orchid. Some commercial growers use Physan 20 once a month to try and keep fungus and bacteria problems in the media under control but even with Physan 20 my pots still often have algae in them. It's a good idea to thoroughly flush the pot with tap water about once a month to keep fertilizer salts from building up and, at least in the case of phalaenopsis, to repot in fresh media once a year.

Hm, that's good to hear at least. Are you sure it's algae though? To my layman's eyes the strands look a lot like the kinds of moss we get here in Sweden.

You're probably right. I still don't think it will cause any problems. I've seen growers use live moss in their orchid pots just as decoration. In nature orchid roots grow in and around moss, algae and fungus. In fact some types of fungus are beneficial to plants.

Alrighty, I'll leave it be in the dendrobium pot and hope for the best =)

Thanks!

Yes, I think the ghost orchid can only grow on a special type of fungus. Also with most organic fertilizers they need a certain bacteria to break down the chemicals.

I'm sure the moss or algae is harmless, it's probably because it has perfect warm, moist and slightly bright conditions up against the glass.

The moss will do no harm but your substrate seem to be alot of fine debris that will hold alot of water. Be careful with water so you do net have a constant wet mess in the middle of the pot while the surface, just inside the glass looks dry!

/M

Brad: Yep, sounds about right. I've had these pots on the window sill for the past few months. Should I move the one with moss in it to a shadier spot for a while?

Magnus: Alrighty, I just repotted the phal on the photo with fresh soil to get rid of the moss anyway. Should be fine for another little while now.

Thanks for your input, guys!

Doh
 

Yes, I was going to say...the orchid in the picture seems that the media is not acting in unison. the bottom seems waterlogged while the top half is drying out. This is not usually the best thing for orchids in general, as they do appreciate a more stable growing condition. Phals should be watered and kept with a bit of moisture, yet some slight drying/aeration is good. having a waterlogged bottom with medium packed to the eyeballs (preventing aeration) will surely lead to rot in the long run. algae or moss is the least of your worries in that case...and I am really hoping you did not actually use "soil" as your medium.:shock: That would be an orchidist 101 no-no.:twocents:

i too, hope that by saying 'soil' you mean BARK chunks....media for orchids does not include soil! even the terrestrial orchids like a finer bark mix, not real soil....drainage is the key with orchids, dens and phals particularly like big chunks of bark that drain fast and clear, without clogging up with small particles....your media looks very broken down and fine....that would encourage moss growth and algae...repot!