My six spirea bushes are in about 85% full sun, with some morning shade. When I bought the property six years ago, they were overgrown, a little messy, but blooming all over. Now, five of them have leaves toward the bottom and toward the top, with dead-looking branches in between. A year ago after their bloom, I pruned about one-third off, but it seemed like they never came back after that. Did I prune too much? Too little? Can I still save them by pruning them closer to the ground this fall?
Dakota County Minnesota
Sorry about the spirea. You did the right thing to prune them, but the best time to prune spirea is in the Spring. Spirea respond to "rejuvenation pruning" meaning you can prune them down to the ground in the early spring.
Keep the plants healthy this season: water and fertilizer. After the spring pruning they should come back fine.
Here is a pruning reference: https://extension.umn.edu/planting-and-growing-guides/pruning-trees-and-shrubs