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Photo credits and licenses
Real photographs from naturalists and photographers worldwide, each used under its own license. Credit: Photo by Stephen James McWilliam / iNaturalist (CC0), Photo by Stephen James McWilliam / iNaturalist (CC0) and Photo by Stephen James McWilliam / iNaturalist (CC0). How photos are sourced →
Butterfly Bush
Buddleia davidii
Also called summer lilac
Butterfly Bush blooms from June through September.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Butterfly Bush
Plant it in full sun. It prefers low water. It is hardy in USDA zones 5–9. Expect it to reach about 6.5 ft tall and 6 ft wide at maturity, in roughly 3 years (not yet checked).
No toxicity note is on file for Butterfly Bush. That is not a clearance: check its safety for people and pets before planting.
What was checked
Mature height and spread, hardiness zones, sun and the trait tags were checked against named botanical sources for this plant. The bloom months and water need on this page were not, and each fact above says which. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Butterfly Bush
Plant Butterfly Bush in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 7, the middle of its hardy zones 5 to 9, spring means March to May and fall means September or October. Once settled, it blooms from June to September.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 7, the middle of this plant's hardy range, start with zone 7 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Butterfly Bush get?
6.5 fttall5 ft 7 inan adult6 ftwideSee Butterfly Bush in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Butterfly Bush
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Butterfly Bush about 6 ft apart, center to center, so each plant has room to reach its full width.
Add Butterfly Bush to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Butterfly Bush's height, spread, hardiness zones, sun and trait tags were checked against 10 published sources on July 29, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- Clemson Home and Garden Information CenterClemson Cooperative Extension Home & Garden Information Centerheight, spread, hardiness zones, sun and trait tags
- Missouri Botanical Gardenheight, spread, hardiness zones, sun and trait tags
- NC State ExtensionPlant Toolboxheight, spread, hardiness zones, sun and trait tags
- The Morton Arboretumheight, spread, hardiness zones, sun and trait tags
- Proven Winnersheight, spread, sun and trait tags
- RHSRoyal Horticultural Societyheight, spread, sun and trait tags
- Iowa State University ExtensionYard and Gardenheight, sun and trait tags
- ipm.missouri.eduUniversity of Missouri IPM (Summer Color from Shrubs)height, sun and trait tags
- University of Maryland Extensionheight, sun and trait tags
- ipm.missouri.eduUniversity of Missouri IPM (Buddleia: A Butterfly Magnet)sun and trait tags
How the checking works, and what each standard covers, is on the verified plants page.
Comes in 11 varieties across 6 colors
Same genus, similar care - pick the color you are growing.
- Black Knight
- Blue Chip
- Empire Blue
- Honeycomb
- Miss Molly
- Miss Ruby
- Nanho Blue
- Pink Delight
- Pugster Blue
- Royal Red
- White Profusion
Compare every variety in the Butterfly Bush group
Every figure is the variety's own page fact. Tap a name to open it.
| Variety | Color | Blooms | Hardiness | Sun | Size (H × W) |
|---|---|---|---|---|---|
| Black Knight | Purple | Jun–Sep | Zones 5–9 | Full sun | 6.5 ft × 6 ft |
| Blue Chip | Blue | Jun–Sep | Zones 5–9 | Full sun | 2.5 ft × 2.5 ft |
| Butterflythis page | Purple | Jun–Sep | Zones 5–9 | Full sun | 6.5 ft × 6 ft |
| Empire Blue | Blue | Jun–Sep | Zones 5–9 | Full sun | 6.5 ft × 6 ft |
| Honeycomb | Yellow | Jun–Sep | Zones 5–9 | Full sun | 6.5 ft × 6 ft |
| Miss Molly | Pink | Jun–Sep | Zones 5–9 | Full sun | 5 ft × 5 ft |
| Miss Ruby | Pink | Jun–Sep | Zones 5–9 | Full sun | 5 ft × 5 ft |
| Nanho Blue | Blue | Jun–Sep | Zones 5–9 | Full sun | 5 ft × 5 ft |
| Pink Delight | Pink | Jun–Sep | Zones 5–9 | Full sun | 6.5 ft × 6 ft |
| Pugster Blue | Blue | Jun–Sep | Zones 5–9 | Full sun | 2 ft × 2.5 ft |
| Royal Red | Red | Jun–Sep | Zones 5–9 | Full sun | 6.5 ft × 6 ft |
| White Profusion | White | Jun–Sep | Zones 5–9 | Full sun | 6.5 ft × 6 ft |
Good to know about Butterfly Bush
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note. A note reports what its source says; where that differs from a fact above, the fact above is this entry's stored value, and its mark says whether it has been checked.
Worth knowing
Despite the name, it feeds adult butterflies but hosts no native caterpillars: it is Asian-native, so no native caterpillar can develop on its leaves. per NC State and University of Maryland
How much water it needs
Established plants are drought tolerant and want low water in well-drained soil, but a new planting needs regular water, and moderate summer soaks improve bloom in heat. per NC State and Missouri Botanical Garden
Invasiveness varies by region
Aggressively invasive and regulated in the Pacific Northwest and coastal California, but only weedy and less problematic in the hot, humid Southeast. Check your state noxious-weed list. per Cal-IPC and Clemson
Regulated noxious weed
A regulated noxious weed: illegal to sell in Oregon and Washington except approved sterile cultivars. One flower cluster can set more than 40,000 seeds. per Penn State and Cal-IPC
Sterile cultivars are legal
Regulated states allow approved seedless or sterile cultivars, defined as producing less than 2 percent viable seed. These curb the seed spread but still are not larval hosts. per NC State and Cal-IPC
Spider mites and drought
Its main pest is spider mites, which flare when the plant is left drought- and heat-stressed. The fix is not letting a tough plant go bone-dry in heat. per NC State and Clemson
Blooms on new wood
Flowers form on new wood, so cut it back hard, to about 0.3 m (1 ft), in late winter or early spring. Never prune in fall or winter. per NC State and Clemson
What pairs well with Butterfly Bush
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Creeping Phlox
Shares full sun and low water; blooms in mid spring, before this one opens; low at 6 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.
Sea Thrift
Shares full sun and low water; opens in mid spring and overlaps into this one's season; low at 8 in, to carpet the ground beneath; evergreen, so the bed keeps its shape through winter.
Candytuft
Shares full sun and low water; blooms in mid spring, before this one opens; low at 10 in, to carpet the ground beneath; evergreen, so the bed keeps its shape through winter.
Grape Hyacinth
Shares full sun and low water; blooms in early spring, before this one opens; low at 8 in, to carpet the ground beneath; both offer pollinator forage, in different months.
Thyme
Shares full sun and low water; low at 6 in, to carpet the ground beneath; opens in late spring and overlaps into this one's season; both are strong pollinator plants.
Wisteria
Shares full sun and low to moderate water; blooms in mid spring, before this one opens; both are strong pollinator plants, and they feed in different months; climbs to 26 ft behind it, height without the footprint.
Hyacinth
Shares full sun and low to moderate water; blooms in early spring, before this one opens; low at 10 in, to carpet the ground beneath; both offer pollinator forage, in different months.
Windflower
Takes full sun to part sun and low to moderate water; blooms in early spring, before this one opens; low at 6 in, to carpet the ground beneath; both are strong pollinator plants, and they feed in different months.
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Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.