Large, brilliant, and long-blooming, butterfly bushes make for beautiful centerpieces in butterfly gardens and landscapes alike. When you’re anticipating innumerable long, pendulous, pollinator-attracting flowers, it can be a serious letdown if your butterfly bush will not bloom. Keep reading for reasons why there may be no flowers on a butterfly bush, as well as ways to get a butterfly bush to bloom.
My Butterfly Bush is not Blooming
There are a few reasons a butterfly bush will not bloom, most of them related to stress. One of the most common is improper watering. Butterfly bushes require plenty of water, particularly in the spring during their main period of growth. In the summer, they need steady watering during periods of drought. At the same time, the roots will rot very readily in standing water. Make sure your plant has adequate drainage to accommodate all that watering.
Butterfly bushes require at least partial and, preferably, full sun to bloom to their full potential. For the most part, they are very hardy to disease and pests, but they can sometimes fall victim to spider mites and nematodes.
In another vein, if you’ve planted your butterfly bush recently, it may still be suffering from transplant shock. Even if it was blooming when you planted it last year, it might still need a year to recover and put down new roots.
How to Get a Butterfly Bush to Bloom
Perhaps the most common cause of a non-flowering butterfly bush is improper pruning. If left to its own devices, a butterfly bush can turn into an unruly thicket with sparse blossoms.
Prune your butterfly bush back in the autumn or early in the spring, before new growth starts. Cut at least ? of the stems down to until only 3-4 inches (7-10 cm) remain above the soil. This will encourage new growth from the roots and more flowers.
If you live in an area that experiences very cold winters, your plant may die back to this state naturally and the resulting dead wood will have to be cut away.