Questions Answered Series: Butterfly Bush (Buddleia)

Questions Answered Series: Butterfly Bush (Buddleia)

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Your Questions on Butterfly Bush, Answered!

Butterfly bushes (Buddleia) are cherished for their unrivaled flower power in hot, sunny gardens. Their blooms combine saturated colors with a rich, honey-like fragrance for an impactful display from summer into fall. If you couldn’t tell by the name, gardeners aren’t the only ones that adore this plant. The real show starts when butterflies and hummingbirds flock to your garden to visit your butterfly bush flowers. What makes this plant even better? It’s easy to grow and low maintenance – with no need to even deadhead the blooms!

Whether you’ve already planted your butterfly bush or are planning to buy one soon, you can find the answers to all your Buddleia-related questions here! See what others are asking and learn why this shrub deserves a spot in your garden.

Close up of purple butterfly bush
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Are Butterfly Bushes Bad for Butterflies?

There is some controversy on whether butterfly bushes are bad for butterflies. Really, butterfly bushes are not bad for butterflies! People can’t live by “bread alone”, and butterflies cannot live on butterfly bushes alone. To create the best garden for pollinators, make sure you provide other food sources (like host plants for larvae) as well. The more plants the merrier.

Is Butterfly Bush Invasive?

Butterfly bush is invasive to some areas in the US, and is even banned in Oregon and Washington. However, plant breeders have focused on developing non-invasive varieties that are packed with color and fragrance without risk of spread. To qualify as a non-invasive variety, a butterfly bush must show less than 2% germination, producing few to no viable seeds.

Butterfly bushes in the Lo & Behold® and ‘Miss’ series from Proven Winners ColorChoice shrubs have undergone rigorous testing and are certified non-invasive, which is why they can be shipped to Oregon and Washington.

Why Isn't My Butterfly Bush Blooming?

There are a few reasons why your Buddleia may not be blooming:

  • Not enough sun. Butterfly bushes require full sun, which means at least 6 hours of direct sunlight each day. It needs this (and prefers even more) to set flower buds and put on the best blooms.
  • Pruned too late. Butterfly bushes bloom on new wood, which means they set their buds on new growth in the spring. If you prune your plant too late, you may be cutting off the future flowers!
  • Too much water. If your butterfly bush is not blooming and is also boasting some yellow leaves, you may be overwatering your plant! Butterfly bushes do not like to have “wet feet”, and prolonged periods in wet soils will make them stressed. A plant under stress is not likely to bloom.
  • Too much fertilizer. These tough shrubs don’t require much (or any) extra fertilizer to succeed in your garden.

Gardeners oftentimes forget how excess fertilizer, especially nitrogen, will promote leafy green growth instead of blooms. Skip on the fertilizer, even in the spring, unless you know your soil is deficient in nutrients.

Can Butterfly Bush Grow in Pots

Yes, planting butterfly bush in containers is the best way to invite pollinators to your patio or porch. They all thrive in containers. The dwarf series of butterfly bushes (Lo & Behold and Pugster) are the perfect size for pots. Make sure you use an appropriate size pot with large drainage holes and keep it in full sun!

Plant: Buddleia 'Miss Ruby' in a pot
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Is My Butterfly Bush Dead?

We hear this question all the time in early spring! The short answer: no, probably not. Plants enter dormancy for the winter, losing their foliage and leaves. New growth emerges when spring rolls around, but some plants hit the “snooze” button instead of waking up early. Butterfly bush is notorious for waking up a little later than the rest. Give them a few extra weeks in the spring to push out new growth. In cold climates, you may have to wait until late May or early June!

How Do I Grow Butterfly Bush?

Butterfly bushes are fairly easy to grow and low maintenance. For the best growth, we recommend the following conditions:

Soil: Butterfly bushes require very well-drained, even dry, soils.

Light: Full sun – at least six hours of bright sun each day.

Water: Low to average watering; soil can even be dry once established. Butterfly bush do not tolerate wet conditions for any period of time.

Spacing: 2 to 4 feet

Fertilizing: Little needed; if desired, apply a granular rose or garden fertilizer in early spring.

Winterizing: In fall, plants can be trimmed lightly if desired, but save major pruning for spring. Do not fertilize in fall, and if mulching, do not apply heavily at the base of the plant.

Maintenance & pruning: Butterfly bushes are best pruned in spring, once the new growth has begun to emerge. At that point, cut just above where big, healthy buds appear. Give butterfly bushes plenty of time to emerge in spring, especially in colder climates – this may take several weeks, even if other plants in your yard are already leafing out.

Will Butterfly Bush Grow in Shade?

For the healthiest and happiest butterfly bushes, you will need to plant them in full sun, which is a minimum of 6 hours of direct sunlight. Ideally, 8 hours of bright, direct sunlight each day will result in the best blooms. Don’t worry! They can handle the intense sun and heat even in summer.

Why are Flowers on My Butterfly Bush Turning Brown

While we wish flowers could last forever, alas, they all eventually fade. Plants produce flowers for one purpose: reproduction! Once a flower has been successfully pollinated, the flowers fade, and energy is diverted into producing seeds in its place. We call these finished flowers “spent flowers”. It’s completely normal to see on your butterfly bushes, especially if they have been blooming for a few weeks.

Don’t worry; just because flowers are fading does not mean there aren’t more to come! As one spike turns brown, you will probably find a new one starting to bloom on a nearby stem.

Buddleia pugster periwinkle with pink-purple blooms
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Should I Deadhead Butterfly Bushes?

Butterfly bushes do not require deadheading, which is why they are considered to be low maintenance! However, you can trim the spent flowers off if you please. It may even help your plant push out a couple more blooms.

How Do I Prune My Butterfly Bushes?

Butterfly bushes bloom on new wood, which means they should be pruned in the spring. Wait until new growth has emerged before you start, then cut just above where big, healthy buds appear. The result will be stronger stems and better blooms!

When Do Butterfly Bushes Bloom?

Butterfly bushes flower starting in summer and into the fall. Once your zone experiences its first frost, you can expect the flowers to fade and the shrub to start entering dormancy.

How Large are Butterfly Bush Flowers?

While each individual flower is tiny, they cluster together to form large spikes of flowers! The size varies based on the variety, but here is a graphic to help give you an idea:

Can I Grow Butterfly Bush in Clay Soil?

Butterfly bushes require well-draining soils, which is the biggest downfall of soils with high clay content. The small particles of clay pack together tightly, leaving little room for water drainage and air circulation. While it can be difficult to grow Buddleia in clay soils, it is not impossible! We recommend planting your butterfly bush so they are slightly above, rather than even with, the soil to encourage water to drain away from the base of the plant. Do not amend or add anything to the soil at planting time, as this can cause serious drainage problems. Skip on mulching around the base of the plant to allow the soil to dry out faster.

Different buddleia plant blooms compared

Is Butterfly Bush Toxic for Dogs?

While they are not edible, they are also not poisonous to dogs, cats, or humans. Eating a large quantity (we mean a lot) of leaves, stems, or flowers can cause an upset stomach. It is certainly safe for your dogs!

Are Butterfly Bushes Deer Resistant

Yes! Butterfly bush is deer resistant. Deer, rabbits, and other garden pests tend to avoid the foliage and flowers of butterfly bush. They receive an A-rating on Rutger’s deer resistance ratings list.

Written by: Miranda Niemic, click here to read bio.

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