Just got my first Oncidium!!
 

I just got my first Oncidium, actually my very first non-phal so I’m really excited. And kind of nervous 😬 so I’m attaching some pictures of it. I wasn’t exactly sure what to look for when picking a “good” plant, so how does it look? I thought 3 spikes was a good sign that it was happy, but I also know growers will force plants to spike sometimes for sale, so that doesn’t necessarily mean much. Any and all care tips you can give me would be super helpful, like I said all I’ve had so far are grocery store phals, and I know these require a bit more care. Thanks in advance, orchid-friends!!

Looks like a happy, healthy plant to me. The main difference compared to Phals is that the Oncidium group needs to never dry out. They definitely like moisture. They root from new growth. The oldest pseudobulbs eventually lose leaves and shrivel, nourishing the new growth. So a difference in growth habit - Phals are "monopodial" plants - basically one growth point, or make clumps - pretty much verical. Oncidiums are "sympodial" - grow along a rhizome (eventually climbing out of the pot)

Once it finishes blooming, and you see new growth, a repot is likely in its future. No rush now. Note the direction of the new growth... you'll take that into account when your repot to optimize room for future growths.

Thank you so much! Can I water it the same way I do my phals? Soaking and then tossing excess water? Would they appreciate misting? I don’t mist my phals a ton but I do have a little spray bottle for that purpose. Will it be happy with the same general light level as the phals?

It might prefer a little more light than a phal, otherwise I treat my oncidiums very similarly to my phals.

Depends what oncidium to know what temps it likes but same as phals should be fine.

Misting is fairly useless. You can use the soaking approach if it works for your Phals. (Personally, I would prefer to water so that it runs through the pot)

That does look like a nice healthy plant. Depending on your temperatures an Oncidium in flower potted in medium bark might need watering every 1-3 days. If they get too dry the newest growths develop horizontal pleating and the flowers fall off prematurely. As Roberta said, you could water by soaking the pot in a bowl of water, or by running water through the pot. Either way it will need watering more frequently than your Phals.

The bark looks good. After these flowers fall off you could leave it in that pot until it grows to the edges of the pot. Or you could repot it, doing so as new growths emerge from the base of the pseudobulbs that just flowered, and these new growths just begin to form new roots.

I don't mist orchids in the house. It doesn't increase humidity for any length of time, and they absorb water through their roots. It doesn't do anything useful.

I especially wouldn't mist Phals if your temperatures are in the 60s-70s F. That would predispose to crown rot.

Thank you! In general what signs should I look for that the plant needs water? I always just wait for the roots in my phals to turn silvery, but I’m not sure if that will still work for the onc.?

That won't work for the Oncidium. Feel the medium... it should be damp. If it's not damp, water it. Oncidiums should never dry out. It should be in a more water-retentive medium than you'd want for Phals. Small bark, or sphagnum would be good choices.

You can hold a freshly watered pot and note how much it weighs. Then water again when it feels a little lighter. You will almost certainly water your Oncidium more often than you water your Phals.

Oncidiums have vermicelli roots, phals have udon roots. Totally different. I use fine grade bark 3-5mm for mine, and these days I add a small bit of sphagnum and some Perlite and Vermiculite in there too, and they are quite happy being watered on the same schedule as my phals (which i pot in much coarser bark.)

You can tell if your Oncidium *was* under watered while it was growing by the fact the leaves will "accordion" (corrugate), which is unfortunately permanent. But if it happens you'll know that for the next growth you need to provide more water. Also minor tip about Oncidiums, if everything goes bad and all the roots die don't lose hope, if the bulb is green and solid then just cut off the dead roots, give it really good humid conditions with a bit of bottom heat and there is a really good chance it will grow new bulbs and come back to life. I have found that Oncidiums are relatively hard to kill once they get a few big bulbs.