I've had a Japanese Lilac Tree growing beautifully in my yard since I planted it about 7 years ago. It's about 10-12 feet high. Last August, a couple of main branches appeared to suddenly die on the shady side of the tree. This spring those branches have so far failed to leaf out, while all the other branches are leafing. I sawed off one of the boughs just now - it was about an inch or so in diameter - and found it to be, to my surprise, green inside with no visible signs of damage. Should I refrain from removing the other "dead" branch - also about an inch thick? How long should I give it to come back? Anybody have this experience?
Any advice would be greatly appreciated. Thank you.