I only use Osmocote on terrestrial plants in pots outside. I prefer the control of how much and when that I get from water soluble ferts for use on orchids and house plants.

tj

I only use Osmocote Plus for citrus and other potted tropical terrestrial plants. I would not use it for orchids.

Regarding mounting plants, you will need to water often if you don't have high humidity. There's really no way around that. This is why I don't have many mounted plants.

With or without humidity, mounted plants need water every day.

I've heard many rave about Osmocote in their catasetum media, because their growing season is so intense and they are heavy feeders.

I have not been successful with providing enough water and humidity to mounted orchids, and won't keep another until I have a terrarium. It's just not possible in my zone. If it won't do well potted, I don't have it.

I use timed release on most of my orchids including the mounties. I think it helps, I really don't know. But, I do fertilize with rainwater for most hand watering.

I live in Florida, plants dry out quickly in the intense sun and heat. The Osmocote works as a back up for me when I use the hose. I've done this for years with no ill affects.

Everyone in my Orchid Society use both methods, Osmocote and liquid fertilizer.

Jane