This week Anne answers a reader's question.
Q: I've sent you a picture of my Phalenopsis orchid which I've had since 2013. There are still new shoots growing with flower buds, but part of the roots are coming over the edge of the pot and drying out.
It looks as if it needs to be replanted. The soil is mostly moss. How soon should I move it into another container? David Chia, Burnaby A: Phalenopsis orchids normally grow new roots outside the pot. This is because in the wild they grow on trees and are used to very humid air around their roots.
But in arid house temperatures, these exposed roots do tend to dry out and eventually need shelter in a pot.
Meanwhile, those roots would love to be misted at least once a day.
Every second year is the best timing for repotting. By then the old roots down in the pot are decayed and the moss/bark mix they're in is probably decayed also.
But, you can't know whether your orchid was newly repotted when you bought it. If it was, then it may not be due for repotting just yet.
It might be helpful to lift your orchid out of the pot and check whether there are decayed roots down there. Also check whether the potting mix is in good shape or brown and in a state of soillike disintegration. Spring is the best time for repotting, after your phalenopsis has bloomed.
So if the photo of your phalenopsis is recent and it is blooming now - and depending what you find when you check the deeper roots, it might be best to transplant now as flowers fade.
If the potting mix doesn't look ready, you could wait until after the next bloom cycle. Garden centres sell special orchid mixes for phalenopsis.
Anne Marrison is happy to answer garden questions. Send them to her via firstname.lastname@example.org