Do Temperature Extremes Affect Tree Health?

This is my first post and want to first give kudos to Scott and whoever else is contributing to making this a place of knowledge and help for those endeavoring to successfully grow fruit.
This question might be for fruitnut,because he is doing it,but if anyone else has something beneficial to add,please do.
I’m starting to grow a group of trees,mostly stone fruits,in a hoop house.The temperatures are getting about 60F outside and easily 80-90F inside,when the sun is not obscured by clouds.At night,the temps can be in the 30’s.Will these variations in temperatures do any damage and should I try to keep the daytime highs inside as low as possible on sunny days,until the nighttime temps rise some? Thanks,Brady

Brady:

Good question and one I’ve thought about quite a bit due to flowering issues with pluot, apricot, and sweet cherry. My current thinking is that the large diurnal variation won’t hurt bloom. The warm days will speed blooming so you need to be able to protect against any late freeze. Also above about 110-120 I’d get concerned esp during bloom. You need a good and reliable ventillation or cooling system to avoid temp above 100.

Right now mid bloom I’m running my greenhouse at 82 high and 39 low. That’s partly to protect a hive of bumblebees. Without the bees 33 at night would be all the same. I never go above 100 on purpose.

Nah. Extreme temperatures can be bad, but the 40 degree ( or more) spread we can get doesn’t seem to do anything.