I have plenty of Rowan/Ash that have self seeded in my garden in the last 5 years.

Some I've kept and trimmed right down to a couple of feet to make shrub like - I usually do this in autumn and they are healthy each spring.

Others I've let grow and just thinned out to lower trunks to make more conventional tree shapes.

Probably a few degrees difference in temp down here in Buckinghamshire. However, up until last week I even lifted some smaller saplings that were in leaf and transplanted to nearby woodland. So far they are doing well, although I did water them in for a few days.

I'm guessing that this a large established tree you are talking about, but from personal experience they seem very tolerant of pruning and even transplanting.

Why are the trees not in leaf? Mine have been for 3-5 weeks now. I would be checking the buds to see if they are green.

THERE IS NOT A LEAF TO BE SEEN BUT BUDS OF GREEN ARE SHOWING I THINK IT IS THE WHITE FLORETS BEFORE THE BERRIES THERE IS LIKE MOSS ON THE BRANCHES,ALL MY NEIGHBOURS TREES ARE FINE.

mANY THANKS iSLA