When is the best time to prune a butterfly bush?How far back should I prune it?Is now OK or not?
Answers:
Depends what type of butterfly bush.Buddleia globosa with the orange globular flowers gets pruned directly after flowering, which is summertime.Remove a third of the wood and thin the bush out.Buddleia davidii,the ones with conical flowerheads get pruned in march.You can remove two thirds of the plant easily.Buddleia alternifolia ,(loose sprays of flowers),prune after flowering which is summertime.Cut back by two thirds the branches that had flowers on them .
Other answers:
It buds in spring? Then prune it in the fall.
It buds in spring? Then prune it in the fall.
After it blooms and the flowers dry up.
the fall
Spring, depending on it's age it is possible to cut it back to 10-12".
I have had these things for years. Prune them as soon as possible. They'll have bigger blooms, and won't flop over as much because the stems will be thicker. Pruning in the fall sometimes kills them. Though it is ideal to prune them back in early spring.
Edit: It's OK to prune in fall BUT you need to be sure the plant is dormant.. This basically means when branches are dead and brown. It's really best to just leave them be because they are one of the most returned plants we carry.
I found this excerpt from a NC State page "The results of the study demonstrate that pruning buddleia before the plants have become fully dormant in the Fall increases the chance for winter injury resulting in death. Growers and homeowners alike should prune late in winter or early spring to decrease the chance of cold injury."
Always prune in the Fall. Prune back 1/3, no more. The growing phase has ended for the winter.
Prune after bloom by removing the oldest wood down to within a few inches of the ground.
Mike Rules is right. Spring time is the best. They are classified as a woody perennial and you can not always tell where it is going to sprout out from. If it is a small one, wait till you see gree coming out and then prune accordingly. Butterfly bushes usually have some winter die back and sometimes by pruning in the fall, you can open up the stems for the cold to go down further. Also, like other answer said, pruning will encourage stronger stems too.