I'm in 5b in Missouri.I have 2 JM are less than 3 yrs old. The smaller one lost 95% of it's top growth. The other one only lost 40% of it's top growth.

We only got to -5 here. How many nights did you get to -20, plus blowing winds with no snow cover? I agree with your landscaper about the pruning not being at fault. Like anyone he does make mistakes ie. Holly incident.

It's hard to trust someone you don't have much history with. Or has he done a lot of other work for you in the past that you weren't satisfied with?

I would assume winterkill as well. Depending on the JM variety, hardiness varies.
Other factors will affect outcomes as well but both this winter's temperatures and duration (continuous days below freezing) has been very hard on many plants that would generally be very hardy.

Many large sorta hardy Japanese maples suffered greatly in zone six st louis. We saw our -10 I believe and were steady cold most of January. Not unheard of but even trees right up next to houses have severe die back.

I am trying to notice if I see any wounds or other signs of long term problems on these trees. Something is in my head like "a healthy japanese maple is zone six hardy. Take away some hitpoints with drought or a wound and it is only zone seven hardy."

I know my nyssa sylvatica transplants are zone six hardy now but that first winter after transplant everyone has suffered.

Salt and de icer are other possible suspects......

Oh, I have a dogwood and three hollies which looked dead three weeks ago. Two are showing a few leaves. Not sure if your tree will do the same. Many of the dead looking Japanese maples around here have SOME new foliage by now.

i would posit.. that pruning never killed any tree ...

especially inside one year ...

one might argue that topping a tree.. willl kill it.. but that would be in tree years.. which means decades...

IMHO ... it was winter ... period..

ken

What do I do with the top that was killed this winter? My JM has new growth at the bottom, and seems okay, but the top looks bad. We had almost three weeks of negative temps here, and three days of sever blizzard conditions.

Michelle, what I am doing with my trees which are not looking well is waiting. A couple reasons.

1 Now is not prime planting time with the heat of summer coming up.
2 They just MAY come back if it was a late frost that killed the buds or something similar.
3 Indecision.

After transplant shock I have had decent luck cutting trees back to live growth then pruning them back into trees.

Now working towards indecision....

My hollies which suffered this winter are somewhat in the same boat as your Japanese maple. There is no reason to suspect another winter in the next two decades or maybe even a couple more winters will not be as bad as this last one. Do I want to put up with a plant which can't handle it?

Indecision! By the end of summer maybe I will decide.

I didn't lose any JM's over the winter but several did experience areas of die-back. I finally got around to taking out the "dead" portions yesterday and saw new growth on them, so there is that.
All you can do is wait and see.

There is no way to tell without seeing the plant and exposure of the plant.

Perhaps you had more wind or more winter sun this year. Perhaps this guy cut back 2/3rds of the canopy. All have a bearing.

We also don't know the cultivar either. JMs have a wild spread of hardiness and adaptiveness to exposures as someone had elluded to. Of my JMs Emperor One is the only one that didn't suffer significant dieback or death. My Orion is bouncing back nicely. But then Lima Gold which is completely out of the wind and winter sun died to the ground with only a sucker coming off the rootstock. Of the larger shirasawanum only Yasemin is alive. Bashful and Autumn Moon where only a foot tall have no dieback as they where under the sun through mid-March.

Thanks everybody. We bought this house three years ago, and the tree was fairly small, not over knee-high. The lady we bought from had been widowed the year before, and her husband was the gardener. I'll wait and give it time. No harm in that!

Here's a current picture; the "dead" top is almost hip-high now. I'm not messing with it.