Bicolor Butterfly Bush Varieties and Similar Cultivars Compared

Pick the wrong butterfly bush and you find out in July, when the spikes open in a color that fights everything around them, or the shrub climbs past the window it was meant to sit under. Pick the right one and you get months of honey-scented bloom and a steady stream of butterflies and bees.

Below, you'll find out all about how Bicolor compares with named solid-color cultivars, including what each one looks like in bloom, how big it gets, and what to do in the first seasons after planting. One of the most common questions we get is whether Bicolor will match the photo on the tag. We'll answer that straight.

Bicolor vs. Solid-Color: What Is the Difference?

Bicolor butterfly bush (Buddleja davidii, Bicolor form) produces two-tone flower spikes. The species itself is lilac-colored with an orange throat, so the exact pairing you get varies by seed strain or grower. "Bicolor" as sold is often a trade name rather than one fixed patented cultivar, and we don't promise a specific pink or rose on any plant.

Solid-color cultivars breed true from cuttings or come from controlled breeding lines. Each named variety locks in its color, size, and bloom intensity, making them predictable from nursery tag to mature plant. Solid colors include deep purples, true pinks, red-toned forms, and even blue-lavender shades.

The real choice is not bicolor versus solid, but rather: Do you want the unpredictability of a seed strain (bicolor), or the guaranteed color and habit of a named cultivar?

Comparison Table: Major Butterfly Bush Varieties

The table below sets Bicolor beside the named cultivars and the dwarf series. The species grows 6 to 12 feet high and 4 to 15 feet wide, so standard-sized plants are shown with that range.

Variety	Bloom Color	Mature Height	Growth Rate	Key Traits	Best For
Bicolor Butterfly Bush	Two-tone mix, varies by seed lot	6-12 ft	Fast	Variable exact tone, seed strain, sweet fragrance	Mixed borders, cottage gardens, pollinator zones
'Black Knight'	Deep purple	6-12 ft	Fast	Darkest cultivar available, long spikes, vigorous	Formal gardens, focal points, high-contrast designs
'Pink Delight'	Soft pink	6-12 ft	Fast, slightly more compact	True pink without purple undertones, fragrant	Romantic plantings, pastel schemes, fragrance gardens
'Royal Red'	Deep red-purple	6-12 ft	Fast	Richest warm tones, bold statement blooms	Warm-color palettes, dramatic borders, sunset gardens
'Nanho Blue'	Blue-lavender	Lower end of 6-12 ft	Slower than standard	Rarest hue, more restrained growth than standard	Cool-color schemes, complementary purple foliage
Lo & Behold Series	Variable (pink, purple, red)	3-4 ft	Slower than standard	Dwarf, more sterile (less seed drop), compact habit	Containers, small gardens, foreground, low maintenance

Bicolor Butterfly Bush: The Seed Strain Option

Bicolor is the cheapest way to get a two-tone butterfly bush, and it blooms from June to September like the rest of the species. Here is what to expect from the seed strain.

The bicolor form as commonly sold is a seed-grown trade line, not a single registered cultivar. This means two plants labeled "Bicolor" from different nurseries may show slightly different color ratios. One might lean more pink, another more lavender.

If you like that natural variation and don't mind minor surprises, bicolor offers charm at a lower price point than named cultivars. The two-tone effect creates visual interest without matching a specific design brief. Its closest relative, the Honeycomb butterfly bush, shows how a named cultivar trades variation for consistency.

Pros: Affordably priced, classic two-tone effect, widely available, and a sweet honey-like fragrance on warm days.

Cons: Color tone is unpredictable across growers. It is treated as a generic trade name, bloom intensity varies by seed lot, and it is not registered as one stable cultivar.

Best for: You, if you embrace variation. It suits pollinator gardens where color matters less than nectar and pollen, and mixed cottage borders where "unexpected" is a feature, not a bug.

Solid-Color Cultivars: Black Knight, Pink Delight, Royal Red and Nanho Blue

Common advice says to buy whichever color is on sale and fix the design later. We don't follow that, because a named cultivar locks in its color. These four cover the main palettes.

'Black Knight': Deepest Purple Option

'Black Knight' is the darkest butterfly bush cultivar available. Its deep, almost midnight-purple spikes stand out even from across the garden.

Pros: Unmatched color depth, long and full flower spikes, vigorous and predictable growth, and a proven cultivar widely stocked by nurseries.

Cons: It can look heavy or somber in soft, pastel plantings. It may need more deadheading to maintain shape because of its vigor, and the deep color can recede visually in shade.

Best for: Formal gardens, dramatic focal points, and high-contrast color schemes. Choose it if you want a strong purple without any pink undertones.

'Pink Delight': True Pink Without Purple Undertones

'Pink Delight' offers clean, true pink blooms without the lavender or magenta cast that many butterfly bush cultivars carry. The color stays consistent from early season through fall.

Pros: Pure pink tone, reliable color, long bloom season, fragrance, and a natural pairing with whites, soft yellows, and cool pastels.

Cons: True pink can fade in intense heat. It is slightly less vigorous than some other cultivars (still fast growing, but a bit more compact) and less widely available than 'Black Knight'.

Best for: Romantic or cottage-style gardens, planting alongside roses and delphiniums, and pink-focused color schemes. It also suits you if you want fragrance in a specific hue.

'Royal Red': Warm, Deep Tones

'Royal Red' bridges red and purple, offering rich, warm tones that read as burgundy or wine-dark depending on light conditions.

Pros: Unique warm undertones, a bold presence in the garden, a place in both warm and cool color palettes, and a full-sized growth habit.

Cons: It can appear brownish-red in certain soils or lighting. It is less common than 'Black Knight' or bicolor forms, and its warm tones may dominate adjacent pastels.

Best for: Sunset-themed gardens and warm-color borders with golden foliage companions. Use it to create drama without pure darkness, or if you want red without losing butterfly bush form.

'Nanho Blue': The Rare Cultivar

'Nanho Blue' is the rarest butterfly bush color in the standard-sized range, offering blue-lavender flower spikes. It is less vigorous than 'Black Knight' and creates a more restrained, sculptural habit.

Pros: A blue-lavender hue rarely seen in butterfly bush, more controlled growth than many cultivars, a good fit with cool-color and purple-foliage schemes, and excellent value for pollinator gardens.

Cons: It is harder to source. Slower growth means more years to reach full size, blue undertones can fade in intense afternoon sun, and it is less fragrant than some pink cultivars.

Best for: Cool-color gardens and pairings with blue flowers and gray foliage. Choose it if you are hunting for a rare cultivar or want a subtle rather than bold statement.

Lo & Behold Series: Dwarf and Container-Friendly

If the standard cultivars are too big for your space, this dwarf line is the one we point customers to. It also changes the seed-drop picture.

Lo & Behold is a modern breeding line of dwarf butterfly bush cultivars available in pink, purple, and red. These plants reach 3 to 4 feet rather than the 6 to 12 feet of the species, and they produce fewer viable seeds (more sterile), reducing unwanted self-seeding.

Pros: Compact, ideal for containers and small spaces, and slower growth means less frequent pruning. More sterile genetics reduce invasion concern where Buddleja is regulated, and the series offers multiple colors.

Cons: Smaller blooms and shorter spikes than full-size cultivars, and a higher per-plant cost as a specialty series. It still needs full sun and good drainage, and it still requires annual hard pruning for best bloom.

Best for: Container gardeners, small yards, and foreground borders. Choose it if you want a butterfly bush without overwhelming size, or live where butterfly bush self-seeding is regulated or invasive.

Which Variety Should You Choose?

Decide in two steps, space first and color second. Both steps change what you should buy.

Start with your space. Do you have room for a shrub that can reach 6 to 12 feet, or do you need dwarf genetics? Then match your color scheme.

Solid-color cultivars let you commit to a palette: choose 'Pink Delight' for romance, 'Black Knight' for drama, or 'Royal Red' for warmth. Bicolor offers flexibility and cottage-garden charm at a lower cost, accepting slight variation as part of its appeal.

Planting and First-Year Care for Any of Them

Once you have chosen, every cultivar here follows the same cultural rules from the day it arrives. These are the steps we give customers.

For planting steps and ongoing care guidance, set the shrub in full sun and well-drained soil. Water moderately while it establishes, then back off, because it grows drought tolerant once established.

Prune in early spring, since the flowers are borne on new growth. Many sources say to cut back hard in fall or late winter, but we wait until buds swell in early spring because the old stems protect the crown through cold snaps. Cut to about 12 to 18 inches from the ground, and see our pruning guide for the details. Then deadhead spent flower spikes through the season to encourage rebloom and control seed drop.

In our rows, the plants that disappoint are usually the ones sited in part shade, not the ones with the "wrong" color.

Quick Reference: Cultivar Selection Checklist

Use this checklist when you are standing in the nursery aisle and need a fast answer.

• Want true pink: Choose 'Pink Delight'
• Want deepest purple: Choose 'Black Knight'
• Want warm, red-toned blooms: Choose 'Royal Red'
• Want rare blue-lavender: Choose 'Nanho Blue'
• Want two-tone color mix: Choose Bicolor Butterfly Bush seed strain
• Want compact, container-friendly: Choose Lo & Behold Series
• Want lower seed drop in restricted regions: Choose Lo & Behold Series or confirm cultivar sterility
• Want affordably priced option: Choose Bicolor or check for local cultivar stock
• Want proven, widely available option: Choose 'Black Knight'
• Want color that pairs easily with other plantings: Choose based on your palette (pink with pastels, deep purple with dark foliage, red-purple with warm golds)

Picking Your Butterfly Bush With Confidence

Choose a named cultivar when color or size matters to your design, and choose Bicolor when you enjoy a little surprise and a lower price. Pick Lo & Behold if space is tight, give any of them full sun, and prune in early spring. Do that and you get honey-scented spikes from summer into fall, with butterflies and bees working them all season.

As a small grower, we hear it when a shrub arrives looking nothing like its tag. That is why we raise our butterfly bushes on our own farms and sell only top-quality shrubs, and why we want this guide to help you choose the right one the first time.