What do I do with this Oncidium?

[bo1075]

I just received this in spike Oncidium Sharry Baby 'Sweet Fragrance' from Orchids by Hausermann. I didn't expect it to be so large, and it seems to be rootbound (if thats a thing with orchids). It's in a black nursery pot, and there are so many roots I can't even tell what medium it's in. It's about two feet tall in a 4" pot.

- How am I supposed to know when it needs water? I can't put my finger in the medium, I can only feel the top surface because the roots are so thick.

-Should I repot it? It's in spike so repotting it would probably stress it out but there are so many roots in that little pot.

I am new to growing orchids but fairly experienced with other plants

[Roberta]

First, Welcome!

If it is in spike, I'd just leave it alone for now. You could drop the whole thing into a larger pot, the air space between the pots will give extra humidity to those wild roots. Once it has bloomed and is putting out new growth, you can repot to a suitably sized pot. Ideally, the new pot should allow space about 2 years' new growth, not more - overpotting can lead to soggy, airless medium and root death. (In general, orchids like to be a bit root-bound) Don't worry about overwatering, these like to stay a lot wetter than a Phalaenopsis or Cattleya. So water until it runs throuth the pot. If you use the "drop pot" approach, those air roots will get good moisture, and likely be very happy.

[bo1075]

thank you so much, it's good to be here! I appreciate your informative response it's very helpful.

I have multiple phals in clear pots with sphagnum moss as the medium and it is very easy for me to tell when they need water because I can see the roots and moss through the pot. This oncidium in a black pot had me confused, especially because I cant see any medium.

[Roberta]

Another note... Roots adapt to their environment. That's why it's so important to wait until new roots have started to grow before repotting - the new roots will adapt to the fresh medium, the ones that have adapted to air will eventually die when moved to another medium, they'll keep the plant going while the new roots develop then their job is done. You may even find that the roots inside the pot mostly gone and that the plant has been depending on the air roots. So if they have a nice humid area between the present pot and an outer pot, they'll be even more helpful.

[Dimples]

Two options for knowing when to water:
1. Give it a really good watering right now, wait 10 minutes, water it again, let it drain for awhile, then weigh it. That’s the ‘wet weight’. Weigh it daily/every other day until you notice the weight change has slowed. That’s your ‘dry weight’. If you’re ever in doubt about it needing water (for the next 4-8 months) you can check by weighing. Eventually you’ll learn the feel of each pot dry and wet.

2. Shove a wooden chopstick all the way to the bottom of the pot to monitor moisture. That plant has roots for days. It won’t notice a little damage. Make sure you put the chopstick back in the same spot every time. That limits the damage to almost nothing. You may even be able to ID the medium used, by seeing little pieces of the medium stuck to the stick.

[estación seca]

Welcome to the Orchid Board!

What a great plant! Take note of how much it weighs in your hands. Dunk it in water until the medium is thorougly soaked, and again note how much it weighs. Oncidiums, especially in spike, should not dry out for long. Water again when it's lighter than it is when wet. An overgrown Oncidim like that might need thorough watering every 2-3 days.

The time to repot will be after flowers are spent and new roots on new growths are forming. That may be 3-4 months. This is a vigorous plant. I would slide it out of that pot, put it into a pot 4" larger in diameter, and backfill with new medium. Do not try to remove old medium unless it shakes free gently. Onc. roots are delicate and easy to damage.

[FranningtonBear]

Welcome!

Really great advice already so nothing much to add other than, don't forget to post a picture when your plant is in bloom so we can all enjoy her with you!

[bo1075]

Thank you for your replies, everyone! I soaked the pot and roots in ro water, let it drain, and weighed it.
I put the plant with its 4-inch pot into a larger square decorative pot for more humidity around the roots.

[Dimples]

A tip for other organizationally-challenged growers:
I record weights/repot dates/etc. on a piece of painters tape (“blue tape” in my household) on the side of each pot. No way to lose the information without also losing the plant.