Buddleja, Butterfly Bush, Orange-eye Butterfly Bush, Summer Lilac 'Purple Emperor'

Buddleja davidii

Family: Scrophulariaceae (skrof-yoo-larr-ee-AY-see-ee) (Info)
Genus: Buddleja (BUD-lee-uh) (Info)
Species: davidii (duh-VID-ee-eye) (Info)
Cultivar: Purple Emperor
Additional cultivar information:(English Butterfly™ Series; aka Pyrkeep)
Hybridized by Keep




Water Requirements:

Drought-tolerant; suitable for xeriscaping

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun

Sun to Partial Shade



This plant is resistant to deer

Foliage Color:

Unknown - Tell us


4-6 ft. (1.2-1.8 m)


4-6 ft. (1.2-1.8 m)


USDA Zone 5b: to -26.1 °C (-15 °F)

USDA Zone 6a: to -23.3 °C (-10 °F)

USDA Zone 6b: to -20.5 °C (-5 °F)

USDA Zone 7a: to -17.7 °C (0 °F)

USDA Zone 7b: to -14.9 °C (5 °F)

USDA Zone 8a: to -12.2 °C (10 °F)

USDA Zone 8b: to -9.4 °C (15 °F)

USDA Zone 9a: to -6.6 °C (20 °F)

USDA Zone 9b: to -3.8 °C (25 °F)

Where to Grow:

Grow outdoors year-round in hardiness zone



Bloom Color:

Medium Purple

Dark Purple/Black

Bloom Characteristics:

Flowers are good for cutting

This plant is attractive to bees, butterflies and/or birds

Flowers are fragrant

Bloom Size:

Unknown - Tell us

Bloom Time:

Mid Summer

Late Summer/Early Fall

Mid Fall

Other details:

May be a noxious weed or invasive

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:

Unknown - Tell us

Propagation Methods:

From softwood cuttings

From semi-hardwood cuttings

Seed Collecting:

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed


This plant has been said to grow in the following regions:

San Jose, California

Denver, Colorado

Wilmington, Delaware

Atlantic Beach, Florida

Hebron, Kentucky

Madison, Mississippi

Levittown, New York

Bucyrus, Ohio

Newtown, Pennsylvania

Regina, Saskatchewan

Clover, South Carolina

Fort Mill, South Carolina

Canyon Lake, Texas

Rosharon, Texas

Spring, Texas

Woodbridge, Virginia

Concrete, Washington

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Gardeners' Notes:


On Aug 2, 2016, coriaceous from ROSLINDALE, MA wrote:

This species isn't long-lived (usually under 10 years). Hard pruning (to 6") annually in early spring helps it renew itself and improves bloom.

All B. davdii cultivars require weekly deadheading for them to look and bloom its best.

Butterfly bushes may be good nectar sources for adult butterflies, but they are not food sources for the caterpillars of any Lepidoptera native to the continental US.

In some places, B. davidii can be an invasive weed: England, France, New Zealand, and the states of Oregon and Washington. It has naturalized in eastern N. America but is not considered invasive there. Recent cultivars are usually selected for dramatically reduced fertility.This species has naturalized along the west coast of N. America from BC to Califo... read more


On Apr 7, 2016, saskboy from Regina, SK (Zone 3b) wrote:

This is one plant that truly lives up to its name. It is to butterflies what catnip is to cats.
Keep in mind when placing it that it will get quite large and is rather ungainly.
In my zone 3b garden it survives reliably but it will die completely down to ground level every winter, however this isn't much of an issue as it grows like mad when the weather warms.
The more sun you can give it, the happier it will be, and it requires well drained soil. Mine grows in gritty soil along the south wall of a barn and is very happy there. Once the root system is well established, it shouldn't need supplemental watering beyond what the rain provides.


On Dec 3, 2011, Suzy_Bee from Spring, TX (Zone 9a) wrote:

Bought this last April and planted it while it still looked like a stick in my hummingbird garden. A few months later it started to grow leaves, and now, seven months later, is 4.5 feet tall, but has still NOT bloomed. It is planted in partial shade. I think I will try transplanting it to a sunnier spot. Suggestions?


On Mar 26, 2009, ShrubSource from Zeeland, MI wrote:

Buddleia - English Butterfly™ Purple Emperor™ Butterfly Bush

Prolific and fragrant bloomer that will attract butterflies and hummingbirds! Purple Emperor™ is extra bushy and loaded with clear bright-purple flowers. It has extremely tight flower heads that are approximately 5 to 6 inches in length. The foliage is narrower, almost strap like. This is a great flowering and neatly growing shrub that is a must for your landscape.

The English Butterfly™ series are colorful Buddleia varieties that won't crowd their neighbors! These three new cultivars were developed in England, and are just now making their way across the Atlantic. Roughly a third the size of other butterfly bush varieties, these plants are extra bushy and loaded with colorful flowers. They're fragra... read more


On Sep 17, 2007, garden_n_mom from North Cascades, WA (Zone 7b) wrote:

This is not a verigated buddlea, though the flower show from June to frost and is absolutely spectacular! Great compact form, non-stop rich purple flowers and very problem free!


On Mar 16, 2007, berrygirl from Braselton, GA (Zone 8a) wrote:

Buddleia 'Purple Emperor'R BUTTERFLY BUSH Dec (z5) (Fra,Cut,Bfly)
Large mauve purple blooms,pretty & fragrant enough for butterflies, gardeners, and flower arrangers, this compact 4-5'shrub can be enjoyed in any yard or in a container. Sun/Med


On Nov 20, 2006, Marilynbeth from Hebron, KY wrote:

Beautiful color! I love it! BF's love it also!