How to Prune a Butterfly Bush - Backyard Boss
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How to Prune a Butterfly Bush

Butterfly bush (Buddleja davidii) plants are sun-loving shrubs that come in an array of vibrant colors, including pink, blue, and purple. The tiny fragrant blossoms cluster into a unique cone shape and, living up to their name, attract pollinators such as butterflies. The shrub continues to produce flowers throughout the summer and fall, reaching 6 to 10 feet tall and 4 to 10 feet wide.

With this plant’s beauty in mind, remember that it grows quickly and requires proper maintenance. It’s even considered an invasive species in some areas. So, how can you control this fast-growing, eye-catching plant?

Below, you’ll discover when and how to prune a butterfly bush. Plus, you’ll find some care tips to ensure it grows in your garden for years to come.

Pruning: When and Why

Butterfly bush (Buddleja) with butterfly
Image credits: WielandTeixeira via Pixabay

While the butterfly bush grows quickly, it dies back to the ground every year when cold weather approaches. So, it’s best to wait until new growth develops to determine when you need to prune the plant.

In late winter or early spring, you may notice foliage and buds that develop low on the plant. It can take several weeks for new growth to form in the spring, so be patient and avoid cutting prematurely.

Waiting until you see new growth ensures you don’t cut “new” wood. The new wood is where the blooms grow, while the “old” wood remains bare. It is not the case for all perennial shrubs, so confirm what type of plant you have and whether it blooms on new or old wood. For example, the Silver Fountain butterfly bush blooms on old wood. And, varieties such as the Sageleaf butterfly bush should be pruned following flowering.

Pruning is essential to maintain shape, keep things tidy, and encourage new growth. If you don’t prune, you’ll notice leggy-ness and fewer flowers since the plant wastes energy on developing and maintaining stems.

Tools You’ll Need

Pruning shears
Image credits: Willfried Wende via Pixabay

To properly prune Buddleja davidii, there are a few tools you’ll need. Fortunately, the list is quite simple! Find the essentials below.

How to Prune a Butterfly Bush

Pruning a butterfly-bush
Image credits: Thijs de Graaf via Shutterstock

Step 1: Cut Back in Spring

Pruning your butterfly bush is simple. Once you see new buds and leaves developing in the spring, you can cut back all the dead old wood on the plant. Using a clean and sharp pair of pruning shears, remove the branches and stems, cutting back to a height of about 1 foot. Make clean, angled cuts above where the leaves appear.

You can also cut the plant into a rounded shape for curb appeal, cutting stems on the outside shorter and keeping them taller on the inside.

Step 2: Remove Dead Stems

With all the old wood removed, it’s time to clear away dead stems and cut or break all dead branches to the ground. Since they’re dead, nothing new grows from them. It’s also a great time to clean up dead foliage from the previous season.

Step 3: Deadhead

Once you’ve pruned the plant in the fall, a butterfly bush requires very little maintenance. Simply deadhead old flowers as they die to encourage new blooms and cut back the plant if you notice it growing too wide or tall; It also keeps the plant looking cleaner. Remember that how wide or tall the plant grows is up to personal preference, and there’s no guideline!

Pro Tip: As you prune and deadhead the plant, add the trimmings to your compost pile.

Butterfly Bush Care

Butterfly bush (buddleja)
Image credits: DominikRh via Pixabay

Now that you’re up to date with pruning your butterfly bush, it’s time to learn how to care for the plant. Find the top tips listed below!

  • Grow in a large container to stop the plant from taking over your garden.
  • Always plant in a location with full sun and opt for well-drained soil.
  • Butterfly bush plants are sensitive to overwatering. Always check the soil before giving your plants a drink and look for signs of overwatering, such as wilting and yellow leaves.
  • While there are many plants you can plant in fall, the butterfly bush isn’t one of them. Instead, plant it from spring to mid-summer. It gives the shrubs plenty of time to develop strong root systems that sustain them through winter.

Give Your Hedge a Haircut!

While pruning isn’t essential for every plant, it is crucial if you want your butterfly bush to thrive year after year. Fortunately, the process is incredibly simple, and your plant will tell you exactly when it needs pruning. New growth in the spring is a sign it’s time to cut back old wood, and spent blooms in the summer are ready for deadheading.

With plenty of sun and proper watering techniques alongside pruning, you should enjoy the stunning blooms every spring and summer.

Do you have any tips for pruning butterfly bush plants? Share in the comments below!