Buddleja

( bud - LEE - uh )

At-A-Glance Information

Butterfly Bush, or Buddleja (sometimes spelled Buddleia) includes species that are very popular choices for butterfly or pollinator gardens. Buddleja is a genus of evergreen, semi-evergreen and deciduous shrubs that require full sun or light shade and moderate to regular water. Shrubs are generally upright and have spreading, pendulous branches. Use Butterfly Bush in mixed beds and borders, as specimens in the landscape, or in wildlife or pollinator gardens.

buddleja Species and Varietals

The genus Buddleja includes 140 distinct species of flowering plants, and is included in the family Scrophulariaceae. Butterfly Bush grows in varying zones depending on the species. For more information, see below species descriptions. To find your zone, click here: Zone Map.

Buddleja alternifolia (Fountain Butterfly Bush, Alternate-Leaved Butterfly Bush, Weeping Butterfly Bush)
This shrub grows best in USDA hardiness zones 5-9 or Sunset growing zones 2b-24 and is deciduous. The species is native to China. Branches have an arching habit and leaves are dull green above with hairy grey undersides. Clusters of fragrant purple flowers appear in the spring. This species tolerates a variety of soil conditions, and can even thrive in poor, dry gravelly soils. Grows to 12 feet tall and just as wide at maturity. Needs pruning after blooms to remove the oldest wood just above the ground. Cultivar 'Argentea' has silvery leaves.

Buddleja asiatica (Asian Butterfly Bush, White Butterfly Bush, Dogtail, Winter Lilac)
An evergreen variety that grows best in USDA hardiness zones 8-10 or Sunset growing zones 8, 9, 14-24, H1 and H2. Native to the East Indies, it is a vigorous grower to 10-15 feet tall and wide. Spikes of flowers appear in winter and springtime, and its fragrance mimics Freesia. Needs pruning after blooms die off. In areas that reach freezing temperatures, it will die back to the ground, but can make a full recovery and flower again in the same year. This species is considered invasive in Hawaii, Guam, Australia and the Northern Mariana Islands.

Buddleja crispa (Himalayan Butterfly Bush, Crispa Butterfly Bush, Waved Butterfly Bush, Orange-Eye Butterfly Bush)
This deciduous species of Butterfly Bush grows in USDA hardiness zones 6-11 or Sunset growing zones 5-7 and 14-17. It is native to the Himalayas and can grow to be 6-10 feet tall and wide. Foliage is silvery grey, and flowers are fragrant. Flower colors are beautiful lilac with orange or white throats. Late summer blooms are the most profuse. Needs to be cut almost to the ground in late winter, and in cold-weather regions should be grown in a container and protected during the coldest winter months. Himalayan Butterfly Bush is considered an invasive species in the western United States (California, Oregon, Washington and some southeastern areas), Australia, New Zealand, and parts of Europe.

Buddleja davidii (Butterfly Bush, Summer Lilac)
This bush is evergreen to semi-evergreen and grows best in USDA hardiness zones 5-9 or Sunset growing zones 2-24 and H1. When mature, these shrubs can reach up to 5-15 feet high and wide. Leaves are long and dark green on top, white underneath. Lilac flowers with orange eyes appear in dense, arching clusters. This species is native to East Asia and was named for French Basque missionary and naturalist Pere Armand David. Summer Lilac is considered an invasive species in the United States (California, Oregon, Washington, Pennsylvania, New Jersey, Virginia), Australia, The U.K., Europe, and New Zealand.

'Alba'

'Asian Moon'

'Black Knight'

'Blue Chip'

'Harlequin'

'Peach Cobbler'

'Pink Delight'

Buddleja globosa (Orange Butterfly Bush, Orange Ball Tree, Round-Head Buddleja, Golden Butterfly Bush)
This species is evergreen or semi-evergreen and grows in USDA hardiness zones 6-9 or Sunset growing zones 5-9 and 14-24. Hailing from Southern South America, this shrub has an open, arching habit and grows to be 10-15 feet tall and wide. Dark green leaves are soft underneath. Flowers appear in early summer or late spring, and are tightly clustered into orange balls in spike-like clusters 6-8 inches long. Needs pruning after blooming, especially on the oldest wood close to the ground.

Buddleja 'Lochinch'
This species of Butterfly Bush is largely deciduous but will retain its leaves in milder climates. Grows best in USDA hardiness zones 5a-9b or Sunset growing zones 3b-9 and 14-24. Foliage is grey and sweetly fragrant. Light lavender to blue flowers appear over a long season in late summer into fall. Grows to be about 5-8 feet tall and as wide. Needs hard pruning (cut back almost to the ground) before spring growth begins.

Buddleja x weyeriana (Weyeriana Butterfly Bush)
This shrub grows best in USDA hardiness zones 5-11 or Sunset hardiness zones 4-24 and can get 6-10 feet tall and wide at maturity. This is a hybrid species and resembles B. globosa but is deciduous and more cold-hardy. Orange/yellow flower clusters appear in late spring and early summer. Varieties include 'Bicolor' (mauve flowers with peach centers), 'Sungold' (orange blooms) and 'Honeycomb' (pictured; with butter- yellow flowers). Weyeriana Butterfly Bush is considered to be invasive in New Zealand, parts of the U.K., and the United States (Oregon, Washington, New York, Virginia).

Caring for Buddleja

Butterfly Bush is considered an easy-to-grow garden shrub and are relatively undemanding in nature. They can be grown both in the ground or in containers and are easy to find at many nurseries, though they can also be grown from seed. Choose a sunny spot in the yard that gets between 6 and 8 hours of sun each day. Butterfly Bush thrives in full sun, but in warmer or dry climates does appreciate some afternoon shade when temperatures are at their peak (typically between 2 and 3 PM). Ensure that soil is well-draining, rich in nutrients, and has a pH of between 5.5 and 8.5 (slightly acidic to slightly alkaline). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Make sure that mulch stays a few inches away from the trunk to discourage fungal disease.

Keep the soil relatively moist (but not wet) for the first 18 months in the ground. Once established, water deeply but infrequently. Mature Buddleja are considered drought tolerant, able to get by on rainwater for most of the year with supplemental irrigation during extended periods of drought. Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flower spikes to neaten up the appearance of plants and encourage reblooms. If a rejuvenation pruning is required, it can be completed in late wintertime or very early springtime. Buddleja shrubs can survive in the landscape for 10-20 years before needing to be replaced. Some species may be able to live for 30 years or more in ideal conditions.

Caring for Buddleja in Containers
Buddleja shrubs are wonderful in the ground, but can also be grown in containers. Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Buddleja plants are considered drought tolerant, even when grown in containers, but will need more frequent irrigation than their in-ground counterparts. Prune to remove dead, damaged, or diseased foliage at any time during the growing season and deadhead spent flower spikes to neaten up the plant and encourage re-blooms. Every few years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot.

Propagation

The best and easiest way to propagate Buddleja is via softwood cuttings taken in the middle of summertime. To propagate your Butterfly Bush, follow these instructions:

Propagating Buddleja by Cutting

Gather your materials. You'll need a clean, sanitized, sharp pair of garden shears, rooting hormone, a pencil, and a 3-inch pot filled with well-draining compost or other organic material. A good substrate for propagation of cuttings is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
In springtime, before the plant has had time to harden its current season's growth, choose the plant that you'd like to propagate. Ensure that this plant has had a good watering the night before, as this will improve the chances your cutting will take root. Cut one or more 4-6 inch portion(s) of the end of a non-blooming branch and strip off all of the lower leaves, leaving the top two on the cutting. Make a hole in your planting medium by pushing your pencil into the soil. Dip the end of the stem in rooting hormone, and plant it in your pot.
Moisten with water, and ensure that the pot has good drainage. Your pot should be kept in cool, sunny conditions indoors (and not in direct sunlight). Water whenever your soil is dry under the top layer. After about four to six weeks have passed, your cutting should be rooted. When you notice new growth on your propagated Buddleja, you'll know you have roots.
Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring, when you can transplant it to its new home in your yard. Ensure that the last frost of the year has occurred before doing this, as it can seriously damage the new plant.

Problems and Pests

Buddleja, or Butterfly Bush, is itself considered a pest in many areas of the world due to its invasive nature. Check with local authorities before purchasing and planting. Buddleja shrubs are generally pest and disease-free, but can be susceptible to developing issues with the following if growing conditions are not met: