Should butterfly bushes be cut back in the fall? This is exactly what to do this season

The question of whether butterfly bushes should be cut back in the fall is one that experts fail to answer definitively. Unlike some seasonal garden queries, knowing how to care for a butterfly bush and how to prune buddleja in fall depends on two significant factors: the first being the size of your plant and the second being where you live. 

It is perhaps no surprise that your list of fall garden jobs differs from those who live in another climate. But how do you know what is best for your butterfly bush? 

Here, the experts help you decide whether you should prune this season – for a strong and healthy butterfly bush (also known as the buddleja) long into 2023. 

Should butterfly bushes be cut back in the fall? 

It depends. According to Lorraine Ballato, a garden expert and author of Success With Hydrangeas, the answer to this question comes down to the size of your plant and your usual winter climate. As Lorraine explains, this is often known as your 'growing zone' throughout the US. 

'Some butterfly bushes are only hardy to zone 6 and warmer. Others are rated for lower zones,' the expert says. You can find out which zone you live in via the USDA Plant Hardiness Zone Map. 

Once you have established your zone, you need to assess the size of your butterfly bush.

'If [your] plant is now at 4 feet plus, you could top it off or cut it in half, but no further,' Lorraine says. This will allow for the inevitable winter kill that will come in the months that follow. 'In the spring, when you see new growth at the base, then you can take it down,' the expert adds. 

Meanwhile, if you have a dwarf butterfly bush, it is better to leave it untouched until the spring, once again, to allow for the winter kill. 'This is a long-lived plant in most cases, as deer and other critters avoid it. It’s also not prone to disease. Its only enemy is cold and stormy weather,' Lorraine explains.

Therefore, if you tend to face a harsh winter climate (where this flowering shrub is marginally hardy), you should make arrangements to protect it from the weather. 'A burlap 'coat' using garden stakes can do the job,' the expert says. 

How do you prepare a butterfly bush for winter? 

Knowing how best to prepare a butterfly bush for winter depends (again) on where you live. As author Lorraine Ballato explains, planning a winter garden is different for everyone, especially in the US, where the climate varies at any given time. 

Nancy Trautz Awot, a horticulture specialist at Burpee Gardening in Pennsylvania, agrees. 'Winter care depends on where it lives. Up north [in the US], it is best to add winter mulch after the ground freezes. Down south, you don't have to use mulch.

How long long do butterfly bushes live for?

Butterfly bushes can live for up to 30 years, suggests horticulture specialist Nancy Trautz Awot.

One way to ensure your plant continues to be healthy, year after year, is by giving it a cut back when spring arrives. 'Regardless of what you do, plan on giving this plant a spring cutback,' Lorraine says. 'The act of pruning will stimulate the plant to produce that growth. Then just sit back and watch the fabulous flowers and the pollinators that flock to them.' 

Therefore, if you're looking for how to attract butterflies, this aptly-named plant could be the best one for you.