A butterfly bush (Buddleia davidii) is an attractive addition to any yard or landscape. In order to keep this woody perennial bush looking beautiful, you must prune it to promote new growth. There are a few tips and techniques for properly pruning a butterfly bush but it is easy to do and worth the effort. You will be rewarded with a fragrant and colorful bush that will attract butterflies, bees, other beneficial insects and even hummingbirds to your yard.
Prune at any time during the year. Butterfly bushes seem to appreciate a brutal pruning whether it is dead heading the spent blooms throughout the blooming period or seasonal pruning before the plant's dormant phase in winter. The butterfly bush is a resilient and hardy plant that will come back year after year and provide you with plenty of fragrant blooms.
Start pruning on one side at the top of the butterfly bush. This will help you keep the desired shape of the bush. Starting at the top of the bush on one side and working down, then starting on the other side can also help you make sure you haven't missed any branches that need pruning. This should be done in late spring or early summer--usually around June--to encourage good growth on the butterfly bush.
Look for dead blooms. Start by cutting any dead blooms or flower heads that are on the butterfly bush. Cut dead flower heads off at an angle. Deadheading spent flowers should be done every 2 weeks during the summer growing period.
Prune the butterfly bush in preparation for winter. The butterfly bush will go dormant in winter in most planting zones. November is the best time to give the bush a final pruning in anticipation of its dormant phase. A butterfly bush may be pruned back to a height of about four feet before winter sets in or it may be cut back completely. Because the butterfly bush is a hardy perennial it will come back the following spring and offer plenty of blooms and beauty.
Dispose of the dead flower heads and pruned branches. Don't leave the dead branches or flower heads around the plant as decay can attract disease and pests. Add the pruned branches and flower heads to your compost pile or brush pile.