Have a 10 yr. old “butterfly tree.” Last year, all branches were full and bloomed. This spring, only new growth at bottom of tree

Question

has leaves? This situation has not happened before. In Pa. this winter, we had three days in a row of zero temps. Do I have a half dead tree?

Answer 1

Are you talking about a butterfly bush, buddleia? I am impressed it thrived for 10 years. Mine don't normally last that long. They are hardy to -20 F (-28.9 C) so I don't think the cold hurt it unless that was very unusual. Do you cut the bush back in late winter or early spring? They can be cut to 6 or 7 inches above ground. Go ahead and cut off the dead branches and see if that encourages new growth.

Here is more information:

https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-pruning-how-to-prune-a-butterfly-bush.htm

If by any chance you meant a chaste tree, those too can be cut to the ground.
https://www.gardeningknowhow.com/ornamental/trees/chaste-tree/chaste-tree-pruning.htm