Humidity

[chrisa]

Yesterday, I had a good conversation with two long-time orchid growers about the humidity level within a greenhouse. One gentleman said that he keeps his greenhouse a constant 70% humidity level all year. The other person said that in the spring and summer her greenhouse is at 70% but fall is 60%, and winter 50%.

Question: What humidity level do you keep your greenhouse.

FYI: My collection is 95% cattleya alliance.

Thanks in advance!

[Phimax]

Hi chriss
70% sounds like ideal but I do not know how to manage that in a greenhouse especially in summer. I have to open the door and 4 roof windows to create temperatures which will not fry my orchids. As soon as the door is open I can spray as much as I want and when i am lucky i keep humidity at 50%.
In winter it is more easy for me with automatic spraying the floors 3 times a day and temperatures which do not exceed 22 degrees celcius and no open doors.

My Catts do really well in this environment

Jan

[BigSteve]

I used to use a fogger to keep the humidity up in my G/H in summer but as Phimax said this does little with doors & windows open to keep temperature down.Now i pot in media that drys out in 3 to 4 days & water more , this seems to help plants , also i use quite a powerful fan to keep air movement up.These are things i can control relatively easily , humidity is whatever it is.
In my grow room humidity is normally above 55% & rises to 65% on the days i water so i water every 3 days.I would like to keep humidity higher but so difficult to do without spending a lot of time & money.
Basically if plants do not thrive in the conditions i have i'll grow another type instead.

[Brutal_Dreamer]

For cattleya orchids the relative humidity should be between 45 and 65%.

cheers,
BD

[jhodgson]

I too have mostly Cattleya alliance orchids. I grow them in a sunroom attached to the back of my house.

I run a humidifier 24 hours/7 days a week.

In Chicago, we can have some very warm summer and very cold winter days. During the summer, I can get the humidity in the 70s/80s in the morning, but will drop into the 30s during a sunny day. In the winter, I struggle to keep the humidity over 50%. Plus, all my potted plants grow on humidity trays.

With that said, my orchids do fine.

[Carolla]

My Cattleyas are house plants in an environment where I'm happy to see 20% humidity! However, they seem to have adjusted and are growing quite happily. They seem happiest in S/H, which I think keeps the local humidity up near the plant, also sitting on gravel trays. I guess I should check right around the plants and see what I have going for them. Cattleyas seem quite tough to me!