Ok, I'm zone 4 and understand that. But what about a tag that only says resistant to these temps. Lets say for example -20 below. Is this ambient temp of should I include wind chill?
Those zone ratings are guidelines. You definitely have to consider your own microclimate when you are deciding on a plant. Boxwood is hardy around here, but cold, drying winds in the winter will brown them out if not outright kill them. My sister lives a mile away, but her development is like a wind tunnel, she's had trouble placing boxwoods in her garden.
Well I hope I didn't just plant a tree to murder it. It's a pear tree rated for our zone. But we do get killer winds in the winter. Going to get up a tall wind brake/privacy fence so hopefully that will help cut the wind enough.
My pear tree is doing fine, but I have a 6' privacy fence around my yard. It does get windy, but I am sure the fence and other trees are helping it stay healthy.
Just my opinion, but I think the drying effect of the wind on the ground and on the foilage is more important than the wind chill. Whether it is chill or drying, wind can be a problem. The wind screen should help either case.
A solid wall causes increased wind speeds, resulting in extreme wind chill on the lee side of the fence.
A hedge filters the wind and slows it down, so that might be a better option, if you have extreme winds.
I am 5a/5b but many say to call ourselves zone 4 (which we're not lol) well anyway I planted two apple trees last year rated for -20 zone 5, we got down as low as -35 and we had insane wind because we're on a hill. The trees are in bloom and doing even better than last year. I'm wrapping my warm weather fruit trees this winter, mostly my nectarines.
Sounds like it might have a chance after all. Heres hoping!
We're not going to put in a solid wall for a fence. But it is going to have wooden slats seperated by a few inches. Later hoping that I can get some virginia creeper to grow up it. I have tried to get shrubs to grow. The wind here is a killer. 35 mph is just a breeze.
I heard our ag agent on the radio about growing trees here last fall. The intense winter sun we have is the number 1 killer. During the day it heats up the trunks and starts cell activation. Then at night they freeze. I painted my trees with a light latex paint and they did great this past winter. Even my poor little crab apple. I swear that thing has lost height since I planted it.LOL