How to know when to repot?

[greenpassion]

I am more familiar with orchids in S/H, so this business of re-potting a phal that's been in moss and or bark is sketchy to me. Do they always have to be repotted every year? I've grown bananas and many other tropicals - and it's easy to tell when they need it. They become nearly root bound. But am I supposed to just repot every year, even when the plant doesn't look root bound? My phals in S/H all have lots of air roots as well as tons of roots growing down into the PA. My orchids in moss/bark don't look root bound, nor do they have any significant air roots above the potting medium.

[RandomGemini]

Well, for moss, I can help you there.

The top of the moss looks broken down, it's very visible. On the plants I have potted in moss that need repotting, you can see that there's greenish looking material on top and the moss fibers become very fine. Fresh moss is sort of fluffy.

For bark, I'm not sure. I repot most plants when I get them home, except for mini phals, which I leave in moss until the spike dies back, then I repot into bark. I did have one seller at an orchid show tell me that you know it's time to repot an oncidium, by the tips of their leaves. If they get a little brownish at the very tip of the leaf, the potting medium is old and it's time to replace it. Not sure if this is true, just passing it along in case it is true. I'm sure someone with more knowledge will come along and post some info for you too.

[Vanda lover]

I repot when the medium is breaking down or the plant outgrows the pot. I find that most of them need it about once a year but there are some that don't like to be disturbed. It partly depends on what kind of orchid it is.

[cbuchman]

There are several reasons to re-pot:

1. The plant is growing over the edge of the pot.
2. The medium is broken down. Spag breakdown is apparent as stated above. For Bark, the orchid stays wet too long and you may see dirt like particles drain out with water.
3. The orchid involved needs regular fresh medium. For example, Zygopetalums are sensitive to salt build up. So I re-pot mine bi-annually regardless of the condition of the medium. Lycastes are often re-potted annually for the same reason.
4. There are bugs in the medium or plant (bugs eggs are often in the medium).
5. The root health is questionable and you need to un-pot the orchid to check the roots. Sometimes this means re-potting.
6. An orchid isn't thriving in what it is potted in now; so you want to try something else.
7. I hate the pot it is in and want to put it into a clay pot (this can also be related to #6)

[greenpassion]

Thank you all for the info!

[RosieC]

Bark can often be left two years, moss is best repotted after one.

As others have said above one of the reasons is that the medium is breaking down. However sometimes that is not as visible as other times. It can 'sour', breaking down in the pot, but not so noticeable on the surface. The chemical balance of it changes and/or the air holes in the center block up.

I've lost plants that I've left too long in the same medium, because it wasn't noticeable that it was breaking down. When I came to repot I found the roots in bad condition and the plants never recovered.

[greenpassion]

Thank you Rosie. I'll check today. I have a mini phal that has been in nearly constant bloom since I bought it 10 mths ago, planted in moss. When all the flowers went by I intended to repot, but it started budding again on the same spikes. It's so happy, but I keep feeling like all that tight moss in that tiny pot can't be good...I've pulled it out to see and it's got enough algae on it to make it difficult to discern the state of of the roots. I'll give another go. Is is ok for me to go ahead and repot while she's full bloomed? I heard it was better to wait.??

[RosieC]

Sometimes you risk loosing the flowers if you repot with it in flower, however I've sometimes left them because they were always in flower, then found the plant got in to trouble if left too long.

I might not hurt to wait, but if it's in nearly constant bloom then at some point you have to make the decision to go ahead anyway. I've made the mistake of not doing and just leaving it and leaving it and had problems as a result.

[strkpr00]

Here are some of my rules, when you water moss and it smells like a stagnant pond it is time to change.
When bark is spongy it is also due for change.
When you pour water onto the media and it holds water and slowly drains...

[greenpassion]

Got it! You guys are awsome.