Should sphagnum moss be replaced annually?

[cythaenopsis]

I think I made a mistake with a phal that gave a wonderful 2nd bloom this year. After the blooming last year, I did not replace the sphagnum moss (as bought) as the plant seemed healthy even up through the blooming season. It added on 4 more leaves too. In fact, after an abundant first bloom this season, I got a second round of blooms (new buds appeared and then did their stuff--smaller and fewer, but still nice).

However, the leaves have begun to show definite signs of shriveling. At first I thought it was because I wasn't giving it enough water. I increased the watering just a little, and the wrinkling started getting worse. So I backed off a bit on watering and still the wrinkling persists. Does this mean that the plant is starting to suffer from root rot? It does have some roots at the surface that have since browned and shriveled up, but then there are a couple of aerial roots that still look healthy. Also, it still has about 6 blooms in progress so I didn't want to remove it from the pot to check.

[Bud]

you can repot Phals while in bloom....I do it right after I bring it home from the store....I want to check the roots and the media....
you have moss for more than a year....I bet it is decaying with the roots of your plant....clean the roots well make sure the old moss is removed from the roots....
use the same pot the plant is in and use fresh moss since you have already been comfortable with that kind of media....unless you want to use the coarse large media mix of bark, charcoal, lava rock and clay bits=but you have to water more

[Paul Mc]

You should check the roots. Phals aren't as temperamental as other orchids when it comes to reporting while in bloom, only subject more to human mechanical error, ie snapping a flower odd be mishandling or accident.

Sphag tends to become acidic after about 1 year, so yes there is the need to repot. However, be aware that if you repot to a drier mix then your phal will also have the stress of adapting to the drier environment. Old roots will not be able to adapt as they were grown for the current sphag mix. If you have plenty of new roots starting once you repot it then you might want to try a half bark mix and half sphag in the pot to ease the transition. Otherwise, you would need to water more frequently to assist its transition in bark mix.

[RosieC]

The best way to know what is going on is to look at the roots. I think it could be suffering if the moss has not changed and it's worth doing that now whether or not that is the cause as it is best to replace it regularly.

Take a look at the roots though, what are they like?

[Ray]

Sphagnum is a GREAT medium, but it will need to be replaced more frequently than most others. Not so much due to decomposition, but because as it ages, it compresses, leading to suffocation of the roots.

Many who use it water from the bottom only, so it only wicks up the water, extending the period of "openness", but I think an annual replacement might be too long if you water from the top.

[WhiteRabbit]

Originally Posted by Ray

Sphagnum is a GREAT medium, but it will need to be replaced more frequently than most others. Not so much due to decomposition, but because as it ages, it compresses, leading to suffocation of the roots.

Many who use it water from the bottom only, so it only wicks up the water, extending the period of "openness", but I think an annual replacement might be too long if you water from the top.

ah - good tip for watering sphag - I have a few small orchids potted in it, and I hate how it compresses from watering
thanks

[Ray]

I have tried a number of things over the years to try to extend the life and make it more forgiving of top watering - I even did layers of moss and coconut husk fiber, or a mix of the two - but all attempts were either relatively ineffective or were just a PITA to do in the first place.

[cythaenopsis]

Thanks for the advice. I did extract the plant and check the roots. It wasn't easy... the moss was packed in there SUPER tight. I found some green roots and some beige, gray, and blackened ones as well, quite flat in contrast to the aerial roots. But the most notable thing was the sparsity of them. I must have been difficult for the roots to push their way through it. In nature, I can't imagine a phal facing that kind of growing situation.

Anyway, I extracted a good bit of the moss and replaced it with fresh content for now. Hopefully with the moss more loosely packed it will give the phal a chance to breathe easier. Once it grows enough roots to be stable, I'll try moving it to a bark medium.

Great tips about watering. I've always watered from the top, so I'll have to try doing the bottom up watering as the primary, with nourished water from the top once in a while.

[msaar]

If you water a phal in sphagnum as often as you do for your other orchids, you can be overwatering severely. A 4" pot likely needs watering once every two weeks, and one in a 6" pot once in 3 weeks. You can't judge when to water by the top of the medium.

[Paul Mc]

Oops!!!!! Thank you for that info! What about Doritis (sp?, sorry it's brand new and I'm not sure of the spelling yet)?