Bicolor Butterfly Bush vs Miss Ruby Butterfly Bush: Key Differences

Both Bicolor and Miss Ruby are Buddleja davidii cultivars prized by gardeners for their long bloom seasons and pollinator appeal. If you're deciding between them, the choice comes down to space, climate, and how you want your shrub to fit into your landscape. This guide walks through the practical differences so you can pick the right one for your garden.

What You Should Know First

Bicolor Butterfly Bush is the standard form of this cultivar, bred for a striking two-tone flower display. Miss Ruby is a patented compact cultivar, meaning it was intentionally selected or bred to stay smaller and more manageable. Both are hardy deciduous shrubs that bloom from early summer through fall, but they'll fit different garden scenarios. Neither is inherently "better" than the other, your space and goals will determine which makes sense.

Side-by-Side Comparison Table

Trait	Bicolor Butterfly Bush	Miss Ruby
Botanical Name	Buddleja davidii (Bicolor form)	Buddleja 'Miss Ruby' (patented)
Plant Type	Deciduous flowering shrub	Deciduous flowering shrub (compact)
Mature Height	5–8 ft, up to 10–12 ft in mild zones	Significantly smaller (check your nursery source)
Mature Width	4–6 ft	More compact (varies by grower)
Growth Rate	Fast, roughly 2–3 ft per year when established	Moderate; slower than standard types
Hardiness Zones	5–9	Same or similar (confirm with supplier)
Sun Requirement	Full sun (6+ hours)	Full sun (6+ hours)
Flower Color	Pink/rose and purple/lavender bicolor spikes	Deep red or ruby-red spikes
Bloom Season	June–September/October (6+ months)	June–September/October (6+ months)
Fragrance	Yes, sweet honey-like scent	Yes, sweet honey-like scent
Pollinator Appeal	Highly attractive to butterflies, hummingbirds, bees	Highly attractive to butterflies, hummingbirds, bees
Drought Tolerance	High once established (after first season)	High once established

Mature Size and Growth Habit

This is where the two diverge most noticeably. Bicolor Butterfly Bush reaches 5 to 8 feet tall and 4 to 6 feet wide at maturity. In zones 8 and 9 with a long growing season, unpruned specimens often stretch to 10 to 12 feet. This makes it a substantial shrub suitable for mixed borders, screening, or as a focal point in a larger landscape.

Miss Ruby, by contrast, is marketed as a compact cultivar. It stays considerably smaller than the standard form, though exact mature dimensions vary by grower and seed lot. If you're working with a small garden, a container, or simply want a butterfly bush that won't dominate the space, Miss Ruby fits the bill better. Expect to check with your nursery for specifics on the particular plant you're buying, since compact cultivars can vary in how restrained they truly stay.

Both grow fast once established, putting on roughly 2 to 3 feet of new growth per year. Miss Ruby will likely be slower, but it still requires annual pruning to keep it tidy and flowering well.

Hardiness and Regional Performance

Bicolor Butterfly Bush is hardy in zones 5 through 9. In zones 5 and 6, it typically dies back to the ground each winter and regrows as a woody-based perennial from the roots. Zones 7 through 9 keep it as a true woody shrub year-round. This flexibility makes Bicolor suitable across much of North America.

Miss Ruby should have similar cold hardiness, though you'll want to confirm with your specific supplier before planting in a marginal zone. The compact breeding doesn't change the plant's fundamental cold tolerance, but growers sometimes select for traits that might slightly shift it. A quick call to your local nursery will clarify whether Miss Ruby thrives in your climate.

Both handle moderate salt exposure reasonably well, making them viable near coastal regions or in areas where road salt is applied.

Flower Color and Bloom Season

Bicolor Butterfly Bush displays a distinctive two-tone flower spike: typically a mix of pink or rose with purple or lavender. The exact shade varies slightly by grower's seed strain, since "Bicolor" as sold in commerce is often a generic trade name rather than one single registered cultivar. But the hallmark bicolor pairing is consistent.

Miss Ruby produces deep red or ruby-red flowers that stand out in the garden with a bold, jewel-like presence. If you want the softer, more romantic two-tone effect, Bicolor delivers it. If you prefer a rich, saturated red, Miss Ruby is the winner.

Both bloom from early summer through fall, typically June through September or October depending on your region and pruning timing. Deadheading spent flower spikes through the season encourages rebloom and extends the display. The flowers are fragrant with a sweet honey-like scent, strongest on warm, still days. Both are powerhouses for attracting butterflies, hummingbirds, and bees.

Sun, Water, and Soil Requirements

Both Bicolor and Miss Ruby demand full sun, meaning at least 6 hours of direct sunlight daily. Blooms and plant habit decline noticeably in part shade, so placement is critical. If your spot gets fewer than 6 hours, neither will perform well.

Water needs are identical for both. Require moderate water during establishment, then transition to drought tolerance within the first full growing season. Avoid standing water or heavy, wet clay soil, which leads to root rot. Average, well-drained garden soil is ideal. Both tolerate poor and sandy soil better than heavy clay.

Soil pH should be between 6.0 and 7.5 for optimal performance. Both are light feeders; a single balanced fertilizer application in spring is sufficient. Over-fertilizing promotes leggy, overgrown plants with fewer flowers, so resist the urge to feed heavily.

Pruning and Long-Term Care

Here's where compact Miss Ruby offers an advantage. Both types flower on new wood, so hard pruning in late winter or very early spring is essential. Bicolor typically requires cutting back to about 12 to 18 inches from the ground or to a low framework of woody stems. This aggressive pruning keeps it shapely and full of flowers.

Miss Ruby's smaller stature means you'll be doing less severe pruning overall, even though the principle remains the same. If you're managing multiple shrubs or garden space is tight, Miss Ruby reduces the pruning workload.

Both shrubs typically live 10 to 15 years of vigorous performance before declining. Many gardeners replace or hard-renovate them after that window as they become less productive.

Pros and Cons at a Glance