shriveled bulbs
 

Hi, can someone bestow upon me the wisdom of the orchid gods? How can I keep bulbs fairly plump, and keep from causing root rot? I've had no luck with my zygo, or oncidium. Is there a mix of specific orchid media that works?
I have an outdoor mini greenhouse; Aliment 60%, and a small fan running. I think they plot against me when I'm asleep. Also, how many days should I keep my cattleya's dry before watering again. Thank you.

What are you prone to over or under-watering? What are you conditions, as in what region are you in? I'm currently experimenting with a peat moss mixture b/c I'm a chronic under-waterer. I have quite a few Zygo hybrids & Oncid hybrids, the Zygos I've specifically wanted to try this experiment with. I'm finding that they may be staying too wet in the plastic pots while the ones in clay pots dry sooner. I'm not exactly recommending this to you just sharing since I'm still testing it out. Otherwise due to my under-watering I tend to favor finer mixes like fine bark mix w/ sphag. Both Oncids & Zygos I've found to be rather thirsty and hungry plants, I also under-fertilize btw. ;) What's your Zygo?

shriveled bubs
 

I'm in NYC. I overwater, even when I feel the media is dry. It can get quite hot in the greenhouse, in the 90's, but I can't find a way to cool things off. I tried using a mister, but water pooled everywhere . I also have a box fan on during the day in the mini greenhouse. I'm just a mess, and my little ones are at the mercy of my incompetence. Any recommendations on cooling the greenhouse, and how long to keep cat's dry? Thank you

Most oncidiums seem to like lots of water but they also prefer to have their roots dry quickly. In Florida I mount them on tree fern fiber totems or put them in wood baskets with chunks of tree fern. I water every day which might not be practical for other growers. I also give them lots of calcium to strengthen the thin leaves. I would recommend using mount, net pots or wood baskets so the roots get lots of air and watering fairly often. You'll need to experiment to see what media works best for you but keep fast drying in mind because those thin roots can rot pretty easily.

Do you have venting in your greenhouse so that hot air can escape? That and some form of misting, or fogging would help. Maybe less mist for shorter time if it is accumulating water too much. If its a smaller greenhouse, then you can buy foggers that increase humidity and should cool things off as well.

This is the mix I have for my oncidium, I use medium to large barks with some chop up sphagnum moss. Ratio is 1 part bark 1/4 moss. I also top it with a 1/2 inch moss ontop to keep the humidity in. I grow in a southwest facing windows, I water every 3-5 days. Hope this helps

Being over-waterer I don't think you want to use peat moss. Perhaps try looking in the Greenhouse growers section...?