Hello from Ohio
 

I am new to this forum and I am looking for advice about solving a problem I am having with an Oncidium that I inherited from a deceased friend's collection. I do not know anything about its variety. I repotted it in October 2024 in a commercially available Oncidium orchid mix. The roots were fine. It has not responded with any new growth since October. There are several stunted pseudobulbs that have not matured. Moreover, several outer leaves have turned yellow and completely drying out. It is in an east facing window that gets morning sun. I water it every 5-7 days with slightly warm distilled water when the top several inches are dry. I was fertilizing it weekly weakly with MSU fertilizer applied after a plain water flush. I have stopped fertilizing it and wonder if the drying of the outer leaves might be due to over fertilizing. I also wonder if the yellowing and drying of the leaves might be due to a nutrient deficiency. I am an orchid beginner and have 2 phals and a Tsiku Marguerite that are doing just fine. I would appreciate any help and advice that I can systematically apply to get the Oncidium pictured to start growing again. Thank you for any assistance you can provide.

Welcome to the Orchid Board!

First, I think there's a very good chance it will live. Oncidium hybrids tend to be very tough and survive a lot of mistreatment.

Oncidium hybrids don't grow much in the cooler, darker times of the year. If it's getting natural light without supplemental electric lighting it won't do much until days get longer and it warms up. If people are able to keep them warm and well-lit all year, they will continue to make new growths all year. But windowsill growers find they are mostly dormant for the winter.

I see three partially mature growths, two with a yellowing leaf at the center. The time to repot Oncidiums is when new roots are barely showing, maybe 1-2 millimeters long. This happens at some time after new growths begin forming. If repotted at other times, some roots are always damaged. The plant then has to survive on damaged roots until the next growth cycle. This may be months. I personally don't repot plants at the wrong time even if the old medium looks in bad shape. I water carefully until the correct time to repot. Others here have different opinions. With Oncidiums I select a pot big enough to hold 2-3 more sets of growth. Your choice of medium is fine.

I suspect your plant had already formed the new roots on the new growths. When you repotted some of the roots were damaged. It's sulking. Those two new growths will probably never get bigger. With good care the plant will begin growing again as it warms up and days lengthen. It should grow on to be healthy. The next growths to form may or may not flower, but the ones that form on them should flower.

I would continue what you're doing and hope for the best. Let us know how it does.

Just an orchid novice here, but hello from Florida.

Thank you for your advice.

---------- Post added at 05:03 PM ---------- Previous post was at 04:57 PM ----------

Thank you for your advice . I will keep you posted on the orchid's recovery.

Welcome!

Welcome!