Help my oncidiums! - Orchid Board

Outdoorsgalmd · #1 02-20-2016, 01:36 PM

Hey everyone. I just joined this site today - looking forward to many discussions to come!

I am a part-time (very part-time - busy job) beginner orchid enthusiast in Baltimore. My house is new construction within the last couple of years, which is relevant because it is super Tyvek-wrapped and has very little air flow as a result. It is so tight and energy efficient that they install a fan that automatically turns on upstairs to circulate the air enough in the top floor. They also installed windows with UV protection to protect furniture and whatnot. This is great for utility bills but not so great for indoor orchid growing! The house is kept at 68 degrees in the winter and I just got a humidity monitor that says it is around 28-30%.

Anyway, I have 3 orchids right now - an oncidium sherry baby I've had for almost 2.5 years that I split into 3 pots about a year ago (bad idea); also it never reflowered...an oncidium tahoma glacier green I've had for about a year, and a Lycaste I've had about a month-which is doing well.

The oncidiums came from the same orchid greenhouse, in bloom, potted in sphagnum moss. My husband buys them for me and doesn't check the roots so both had kind of rotten-y moss that I repotted pretty soon after flowering into a bark/perlite/charcoal mix. This did not do so well - the pseudobulbs withered, leaves yellowed, and mold/mushrooms(!) grew in the pot after I tried to be more diligent with watering. I think this is because of my poor air circulation. At the time I thought my house must be too humid too, so I did some research and decided to try LECA for both oncidiums about 9 months ago (also when I split the sherry baby). When I repotted the roots were in bad shape.

At first, both oncidiums seemed to love their new media. Lots of healthy new roots and new growth popped up pretty quickly. I use the skewer method to know when to water. Over time, though, the new pseudobulbs and leaves keep growing in all wrinkly. Last month, one of the sherry baby plants dropped a bunch of leaves and a couple of pseudobulbs died, so I repotted it and cut off the dead growth. It seems to be ok again...

My most healthy sherry baby has taken a turn for the worse though, and over the last couple of days several leaves have turned yellow and older pseudobulbs turned brown. I haven't done anything different than normal and haven't repotted it since last May.

The Tahoma has never been as healthy since I got it, and it has been slowly struggling as well.

HELP! What can I do to improve the health of my oncidiums? I am going to move them all to the sunniest/warmest (probably 70-ish) room in the house, get a fan, and do humidity trays. Should I repot and cut off the dead growth? use different media?

Photos are attached - first 3 are of the sherry baby that was healthiest but deteriorated this week. next one is the sherry baby i had to cut off dead growth and repot a month or two ago, and the last two are the Tahoma that has always been a little unhappy...

TIA!

campchi · #2 02-20-2016, 04:41 PM

Oncidium prefer moist environment, not wet. Clay pellets are drying too fast for it. You cam grow it in semi-hydro with leca. If you have low humidity, you might want to mix with 25% moss in it to keep the moisture. Hope that helps.

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silken · #3 02-20-2016, 05:09 PM

Welcome to Orchid Board. They look too dry to me. As mentioned, Oncidiums prefer not to dry out completely and those Leca balls look pretty dry. The pots look big too. I usually put them in a mix of fine bark or even medium bark with a bit of moss. They need some air to their roots but because they are very fine, they dry out quickly.

How dry is your skewer before re-watering? A small humidifier might work better than humidity trays which really don't add much humidity. Be careful if moving them to a brighter spot. Oncidiums like good light, but not direct light and you could stress them or cause sun burn. Sometimes setting up a shelf with some lights gives you better light control.

You could try some kelp (seaweed) solution in your watering now and then to help promote root growth.

estación seca · #4 02-21-2016, 02:11 AM

Welcome! What they said.

Outdoorsgalmd · #5 02-21-2016, 08:56 PM

Thanks all! I am going to try out SH with the leca. The skewer would be cold to my face but not damp, but the top layer of leca would dry out much faster so I think it was to try. Also ordered some kelp. Crossing fingers!

DeeP0 · #6 02-24-2016, 07:00 PM

Another thing that might be stressing them out is all the changes. The more you change their environment (media, location and all), the less happy they'll be. Also, if you were changing all these medias while the roots were dead and dying, they won't adjust. Usually only new roots on new growths will adjust to new media.

Leafmite · #7 02-24-2016, 09:52 PM

I just moved my Oncidium Heaven Scent (closely related to Sharry Baby) from moss to LECA and a basket pot and I find that in that set up, under the lights, I need to water daily as the LECA is drying out very quickly. I can see some of the roots at the edge of the pot and I find that helpful in determining when to water. I let them soak for a few minutes, to give them time to absorb some water as Oncidiums tend to be thirsty orchids.

They all look as though they might survive. I would give the Oncidums more light. I don't grow Lycaste so I cannot advise you on that one.

If your windows are coated, you could always buy a shelf and a T5HO light and grow your orchids under the lights. I am actually growing lettuce, gardenias, citrus, coffee, piper and orchids under artificial lights as my other plants have taken over the windows.

Zabeta · #8 02-25-2016, 01:45 PM

I'll just add my two cents that oncidiums, in my experience, are very resilient. I have several that are super wrinkly and flat that I've been keeping around because I don't want to toss them and out of curiosity to see what they'll do (if anything). The other day, after months of nothingness on the worst one (but the one with my favorite flowers), I was very surprised and pleased to find multiple new growths starting - five or six. It'll be a long road before it looks nice again, but it's not going to die anytime soon.

My point is that despite a naturally bad environment for oncidiums PLUS some unwitting abuse of them on my part when I was still learning what to do, none of them have died. Sharry Baby in particular is THRIVING and has bloomed twice in the last three months. It's a very hardy hybrid. I do confess that I threw a couple away when I was really frustrated with them, but after seeing the progress of the absolute worst one, I regret giving up so easily. They probably would have survived and eventually recovered. And all oncidiums are so beautiful.