When to re-pot my new Shelob Tolkien?
 

I bought this plant yesterday from Laurence Hobbs Orchids’ stand at the Royal Horticultural Society Tatton Park Show. It has one spike in flower and two more in bud. There are so many pseudobulbs that it’s hard to count them but it’s something like ten or twelve and there is one new growth at one end of the rhizome and two at the other, from which it’s produced the spikes.

I’d say to call it congested in its 12cm pot would be an understatement! My instinct would be to re-pot immediately but with three spikes to potentially lose that seems an overreaction. If I soak the pot as I would my other orchids and spray the exposed roots a couple of times a day will that keep it happy until the last flower fades? That could be quite a while, of course.

Keith

If it was my plant I'd leave it in that pot for now, and proceed as you suggest (assuming there is a nice healthy root ball in that pot). I don't think misting the exposed roots is necessary though. You may need more frequent watering though, seeing how thirsty a large pot-bound Oncidium can be!

You can also stand it in a large container and keep a bit of water in the bottom. Camille is right, that will be a very thirsty plant. Divide when the flowers fade. That's a great find.

There are new roots emerging from the new growths and all of the pseudobulbs are plump so I would imagine that there are a fair number of active roots. My plan is to stand the plant in a humidity tray to give it as much moisture as I can. What also crosses my mind is, rather than use a tray, to use a suitable plant-pot holder so that the humidity released is kept closer to the pot and the exposed roots.

Keith

---------- Post added at 11:45 AM ---------- Previous post was at 11:38 AM ----------

I planned to use a humidity tray but your idea of a container sounds a better option.

My jaw literally dropped when I lifted the plant up for the first time. It’s clearly quite an old plant and could have been used for three or four divisions as it stands so I wonder whether the commercial nursery that grew it - Lansbergen Orchids in The Netherlands - sent it out by mistake. Not that I’m grumbling! :biggrin:

Keith

Forget a humidity tray, those do nearly nothing. A better plan, like dolly suggests, is to let it sit in water. I completely forgot to mention that my large Oncidium types spend the warmer months sitting in saucers full of water. They usually take up the water in 2-3 days, I leave it dry 2 days, then refill. Water hogs enjoy this treatment!

Camille is spot on. I grew my very root bound Oncidium "Sharry Baby" in a large, square, glass vase with water in the bottom. This gave the arial roots humidity and the thirsty plant continuous moisture. When it quit blooming, I repotted into an 8" pot. I recently posted a picture.

These posts contradict what I’ve read that orchids don’t like wet feet. Is it only members of the Oncidium tribe that this applies to?

Keith

Your plant is so potbound, you will have a hard time keeping it watered. Truly, most plants don't like wet feet but, yours is an exception. The Oncidium tribe like moisture and you have a large mass to contend with. You are more likely to error on underwatering this one.

There are others in the Zygo family that I grow in standing water. And there are surely others I'm not familiar with.

Thanks for the clarification. I have a better idea of where to go now.

Keith

Many Phrags (the riverbank species and their hybrids) also enjoy having their feet wet.

After a lot of experimenting with saucer size and medium type/grade, I grow a number of other thirsty orchids with a small saucer of water (never more than what is taken up within 2 days), such as my Paphs, my huge Maxillaria tenuifolia and a few other odds and ends. It works well when there is a large amount of roots to take up that water quickly.

I am absolutely not an expert, but I believe it's been fairly conclusively demonstrated, when it comes to orchids, the phrase "likes to dry out" may be more easily interpreted as "drowns or rots easily", and literally all orchids will do well naturally with aerated, clean water dampening them if the orchid is in the higher end of it's maximum growing conditions. It seems as though lots of orchids just either have really tough to maintain "natural" maximum growing conditions so wet roots will make them lose to fungal infections, or they flower better if their hormones are allowed to concentrate through growth restriction, so they need to dry out in "natural" conditions but can be induced to flower in artificial environments through flushing nitrogen.

I hope that's stated with enough caveats as to not bring down wrath at the generalizations.

Bearing in mind the comments about keeping it damp because it’s so pot-bound I’ve been standing it on damp aquarium gravel and the moisture is wicking to the surface. At the moment it seems happy enough. The second largest spike is progressing nicely and the brown spotting on what’s currently the inside of the bud is showing through the closed sepals. The open flowers when I bought the plant have been distorted by the plastic sleeve it came in so I’m looking forward to seeing flowers from this spike that are in their prime before much longer.

Thanks for the interest.

Keith