I have a 10 foot tall crabapple tree that I planted 3.5 years ago. It's done very well each year, enjoying lots of new growth and flowering. This spring it appeared the very top foot of the tree died as I saw no green up there. The rest of the branches grew lots of green leaves. I just returned from a week of vacation and found all of the green leaves had turned brown and shriveled up. I see no new growth. I'm told we received a lot of rain the week I was gone, so I'm not sure if that was the culprit. I also noticed a lot of suckers at the base which I promptly removed. Can I do anything to save this tree? If I prune all of the dead limbs will that help?