Good minimum GH temperature.

[BrassavolaStars]

Hello all,

I have my heater going and I was wondering what a good temp minimum to maintain in the greenhouse would be.

Currently the minimum is about 64F.

I grow everything from Cymbidiums to Phals, Vandas, and renantheras. What is a good min temp to keep that won’t cost me too much money.

[Fairorchids]

I grow all of the above, except for Phals. I also have a lot of Cattleya and a good number of Dendrobiums.

In my current greenhouse, we aim for min. 55F night time temp, and in the daytime the ventilation kicks in at around 80F. Used the same settings in my previous greenhouse.

I do avoid true warm growing plants (which typically need min 65F at night). The only plant we have ever had a problem with, is a Cattleya that is half dowiana.

[Ray]

In PA, my greenhouse was heated with propane. My budget payment (monthly, all year to pay for winter heat) was $400. Yes, you’ll want it to be as low as is safe for the plants.

However, before you “set it and forget it”, be aware of two factors:

• Thermostats, being reactive controls, will close as the temperature falls and there is a lag between the heater coming on and the volume being warmed. That means that if you want a certain minimum, you’ll likely need to set the thermostat a bit higher.
• Even with fans running to distribute the heat, there will still be cool spots and warm spots. Make several measurements to determine the profile within the GH, just as you would with light levels, then you can position the plants properly.