Dark Knight Spirea Possibly Killed By Late Frost

Question

We have had 4 dark knight Bluebeard spirea bushes for about 1 1/2 years. Last spring I trimmed back the flowering buds when the leaf growth started and they did great. They are about 2’ before the blooms which were another foot. This year we had a late frost in April that froze the leafy growth at about 1/4”. I trimmed again but the plants still don’t show any new growth where there is dead frozen new growth. It is now late May. Did these bushes probably die or is there still hope they will bud out again soon where the new buds froze? What should I do. There is also no growth from the roots. The picture attached is before this years trim. Thanks

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Answer 1

I would cut them to the ground and if you don't get any new growth by mid June, just replace them. I find butterfly bushes to be short lived. They look good for a couple of years, but after that they seem to decline in the colder zones.

https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/how-to-revive-butterfly-bush.htm

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