Black Knight Butterfly Bush (Buddleja davidii 'Black Knight') | Dark Purple Flowering Shrub

Black Knight Butterfly Bush

1 Gallon

$18.90

Black Knight Butterfly Bush

Buddleja Lo & Behold 'Blue Chip'

A fast-growing, hardy shrub with spectacular, fragrant, near-black flower spikes that are a magnet for butterflies and other pollinators.

$18.90

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Bay Area–Based Nursery

We specialize in plants grown and delivered in their original pots and soil.
Because of their size and weight, our plants are not suitable for long-distance shipping and are delivered locally to ensure health and quality.

While delivery is limited to our local service area, we’re happy to support garden design and plant selection remotely.

For local plant professionals, we’re always glad to connect and explore ways to support your customers.

Buddleja davidii 'Black Knight' is a classic and dramatic deciduous shrub, prized for its exceptionally long, fragrant panicles of very dark purple flowers that appear to be almost black . This vigorous, fast-growing plant is a cornerstone of the pollinator garden, as its nectar-rich blooms are a powerful magnet for butterflies, bees, and hummingbirds from midsummer through fall . With its arching, vase-shaped habit and silvery-green foliage, it provides a bold, colorful accent and a reliable late-season source of color when many other shrubs have finished blooming .

Knowing how we measure the size?

When browsing our plants, you may notice size terms such as Gallon, Multi, or Stand. These describe how a plant is grown, containerized, or structured at the time of sale — not just its height. Understanding these terms will help you choose the right plant for your space and expectations.

🌱 Gallon Size (Container Size)

Gallon refers to the size of the nursery container the plant is currently growing in (e.g. 1 Gallon, 5 Gallon, 15 Gallon).

A larger gallon size generally means:
- A more established root system
- A sturdier plant
- Faster visual impact after planting
Example:
- 5 Gallon: Ideal for residential gardens, easy to handle, good balance of value and maturity
- 15 Gallon: More mature, provides quicker results in the landscape

Note: Gallon size does not guarantee a specific height, as growth varies by species.

🌳 Multi (Multi-Trunk / Multi-Branch Form)

Multi indicates the plant has multiple trunks or main stems growing from the base.

Commonly used for:
- Ornamental trees
- Feature plants
- Japanese maples, olives, crepe myrtles, etc.
Why choose Multi:
- Fuller, more sculptural appearance
- Strong visual presence even at younger ages
- Popular for design-focused landscapes

🌲 Stand (Single-Trunk / Standard Form)

Stand (short for Standard) refers to a single, dominant trunk with a raised or naturally formed canopy.

Commonly used for:
- Shade trees
- Street trees
- Orchard and structural plantings
Why choose Stand:
- Clean, classic tree form
- Easier clearance for walkways and lawns
- Preferred for long-term structure and uniformity

🌿 Choosing the Right Size

If you want instant impact → larger Gallon, Multi form
If you want long-term structure → Stand form
If you want flexibility and value → mid-size Gallon containers

If you’re unsure which size or form fits your project, our team is happy to help you select the best option based on your space, timeline, and design goals.

Features:Foliage: Narrow, lance-shaped leaves with velvety gray-green texture,Flowers: Dense conical panicles of magenta-violet blooms with golden-orange centers,Habit: Compact, mounding semi-evergreen shrub
Mature Height: 2-3 ft
Mature Width: 2-3 ft
Growth Rate: Fast
Light Needs: Full sun (6+ hours daily)
Key Advantages:Non-invasive sterile variety,Continuous summer-to-frost blooming,Highly attractive to butterflies/hummingbirds,Superior cold hardiness,Drought tolerant once established
Landscape Uses:Pollinator gardens,Container plantings,Low borders,Rock gardens,Mass plantings
Special Care:Pruning: Cut back to 6-12" in early spring,Soil: Well-drained; adaptable to pH 5.0-8.5,Water: Weekly until established, then drought tolerant,Fertilizer: Balanced slow-release in spring
Seasonal Interest:Flowers: June through September,Foliage: Semi-evergreen in zones 7-9

Q: How should I prune my Black Knight Butterfly Bush?
A: It blooms on new wood . Prune hard in late winter or early spring (March), cutting the previous year's growth back to within a few buds of the base. This encourages strong, vigorous new shoots and the most abundant flowering. In cold climates, it may die back to the ground but will regrow from the roots .

Q: Is Black Knight Butterfly Bush invasive?
A: Yes, it can be invasive. It self-seeds readily, and Buddleja davidii is classified as invasive in several US states (including parts of the East, Oregon, Washington, and California) . To prevent unwanted spread, remove spent flower spikes before they set seed.

Q: How much sun and water does it need?
A: It thrives in full sun (at least 6 hours per day). It is very adaptable to soil types but prefers a moist, well-drained location. Water regularly during the first growing season; once established, it is drought-tolerant .

Q: Does it really attract butterflies?
A: Absolutely. It is one of the most renowned butterfly and pollinator plants . Its fragrant, nectar-rich flowers also attract hummingbirds and bees throughout its long bloom season .