Sounds like a great idea. I'm going to start that myself. I've already noticed the soil seems much colder than the air and I even used room temp water. How big is your greenhouse?

I just have a small 6 by 8 greenhouse a lot of pictures of our greenhouses in bugs 11 if you look at the pictures.
Trace

I use just slightly warm water - just enough to take off the chill from the tap. I use warmer water when I mix fertilizer so that it dissolves / mixes well, and then I let it cool a bit before use.

Josh

Trace,

Thanks for sharing that; it is how we all learn. Experience is not the best teacher; it is often expensive and distressing. Learning from the experiences of others is the best way; it is free and mistake free. That is the beauty of these forums (fora, for the purists).

I also use warm water for my trees, I go one step further and warm my trees roots at night with a heating pad. Roots are nice and toasty when the lights come on. I have never had a huge drop in leaves. Jack

I started using warm water about 20 months ago. I started with water about 100 F. I got bolder and up the temp tp about 120 F about 14 months ago. I add the water very little at a time so I didn't hurt the roots but was able to heat the dirt down deep. This year I poor 120 F water in the compost /mulch that insulates the tree roots and I pour 160 F water around the trees beyond the root base into the compost pile the trees were placed on top of. This goes deep under the trees active roots and warms the whole bed. This has worked well. All my trees are in ground or containers to big to handle individually and all my trees are outside permanently and under glass will little heating.

Steve

Steve

Thanks Johnmerr its so true I'm glad I can help ppl love this forum.
Trace

We keep 4-5 5 gallon buckets full or water inside the greenhouse. That way when its time to water the water is at the same temp as everything else. Been doing that for the last couple of winters and have had no leaf drop. We keep the greenhouse at or above 60F.