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Want your garden to bring all the butterflies to the yard? Look no further than butterfly bush, a low-maintenance, easy-to-grow perennial that beneficial insects love. Here's everything you need to know about growing butterfly bush in your garden.
- Botanical Name: Buddleja davidii
- Common Name: Butterfly bush, summer lilac, orange eye
- Plant Type: Deciduous shrub
- Mature Size: Six to 10 feet tall and four to 10 feet wide
- Sun Exposure: Full sun
- Soil Type: Well-drained soil
- Soil pH: 5.5 - 7.0
- Toxicity: Nontoxic
After planting your butterfly bush, apply a few inches of organic mulch around the plant to support fertility, keep down weeds, and keep the soil from drying out in hot weather. Water the plant once per week if it doesn't rain, and more often in very hot, dry weather (just make sure not to overwater, which can cause root rot).
Help your shrub look tidy and prevent unwanted spread by deadheading spent blooms before they set seed. Prune the entire plant down to one foot above the soil line in late winter or early spring to encourage vigorous growth and lots of blooms in the new season.
Butterfly bushes are highly invasive in the United States, so you'll want to be vigilant about keeping them from spreading outside of your garden.
Best Growing Conditions for Butterfly Bush
Butterfly bushes can thrive in a variety of conditions as long as they're in a site with well-drained soil and full sun. These shrubs are cold-hardy in growing zones 5 through 9; in colder climates, plant them in containers so you can overwinter them indoors.
Types of Butterfly Bush
While the classic butterfly bush has light purple flowers, different cultivars and hybrids offer blooms in shades of white, purple, blue, yellow, orange, and pink. Different varieties of butterfly bush can grow to different mature heights, too.
Large cultivars that grow taller than six feet include 'Pink Delight,' with large, protruding clusters of bright pink flowers, and 'Black Night,' which features dark purple flowers against deep green foliage. For round rather than pointed clusters of yellow flowers, try 'Honeycomb' (Buddleja x Weyeriana).
If you're looking for a butterfly bush that won't outgrow a large container or a small space, try compact varieties like 'Ellen's Blue' or 'Summer Beauty,' which grow under six feet tall at maturity. The smallest dwarf variety, 'White Ball,' maxes out at three feet tall.
How to Propagate Butterfly Bush
Butterfly bush is easy to propagate via stem tip cuttings in the spring.
What You'll Need
- Healthy, mature butterfly bush
- Sharp, sterilized pruners
- Rooting hormone powder
- Soilless growing medium or a mix of equal parts perlite, peat moss, and coarse sand
- Small plant pot
- Clear plastic bag
- Fill a small plant pot with a soilless growing medium. Use your finger or a small stick to poke a hole in the growing medium about halfway down in the pot.
- Select a stem from the mature plant's new growth, ensuring that there are several sets of leaves and avoiding any woody stems.
- Make a diagonal cut about six inches below the end of the stem, just below a set of leaves. Remove the leaves from the lower half of the stem, then dip the lower end of the cutting in rooting hormone powder.
- Plant the cutting three inches deep in the growing medium, patting the soil down so that the cutting stays in place. Water it well, then cover the plant with the clear plastic bag and fasten it around the pot to hold in moisture, making sure not to damage the cutting.
- Leave the cutting in a warm place with bright, indirect light. Check the soil frequently and water to keep it evenly moist but not soggy.
- Check for roots after about six weeks by gently pulling on the stem—if you feel resistance, that means roots have formed. Plant the cutting and care for it as usual.
Common Problems With Butterfly Bush
Overall, butterfly bush is a very hardy, vigorous plant without a lot of issues. Plants stressed by drought can be susceptible to spider mites, while long periods of cool, wet conditions can lead to downy mildew. Pesticides aren't recommended for use on butterfly bush since pollinators like butterflies and bees frequent the plants for nectar.
How to Get Butterfly Bush to Bloom
Since butterfly bush flowers appear on new growth, it's a good idea to prune back older stems in late winter or early spring. Skipping pruning or pruning too late in the season can impact blooming.
Since butterfly bushes are such vigorous growers, it's not necessary to fertilize them. Fertilizing will cause your butterfly bush to use its energy on growing new foliage, not flowers. In exceptionally dry, hot conditions, your butterfly bush may need additional water to bloom properly.
Is butterfly bush easy to care for?
Yes, butterfly bush is known for being a low-maintenance plant that's easy to grow.
How fast does butterfly bush grow?
Butterfly bush is known for its rapid growth, up to two feet in height per year or more. It can reach its mature size in just one or two growing seasons.
Is butterfly bush good for pollinators?
Butterfly bush looks beautiful and attracts butterflies, but it can be extremely invasive in the United States. It's considered a noxious weed by the USDA because it can displace native flowers and impact agricultural and forest plants.