Botanical Name: Penstemon hybrid ‘Rock Candy® Ruby’

Common Name: Beardtongue

Hardiness Zone: Perennial in Most Climates (USDA Zones 4–9)

Size: 12–16" Tall × 12–18" Wide

Growth Habit: Compact, Upright, Well-Branched

Sunlight: Full Sun to Partial Sun

Soil: Well-Drained Soil; Tolerates Average to Poor Soils

Water Needs: Low to Moderate; Drought Tolerant Once Established

Bloom Season: Late Spring to Early Summer

Fertilizer: Light Feeding in Spring; Avoid Excess Fertility

Features: Rich Ruby-Red Flower Spikes, Compact Habit, Strong Stems, Deer Resistant, Pollinator Friendly

Uses: Borders, Containers, Pollinator Gardens, Rock Gardens, Mixed Beds

Patent: ✔ Patented

Propagation: ❌ Propagation Prohibited Without License

More About Penstemon ‘Rock Candy® Ruby’

Penstemon ‘Rock Candy® Ruby’ delivers strong, saturated color without the height or fuss of traditional penstemons. The flower spikes emerge in late spring, bringing deep ruby-red tones that stand out clearly against the clean green foliage. It’s an excellent choice when you want noticeable color early in the season but need the plant to stay in scale with surrounding perennials.

Like the rest of the Rock Candy® Series, this variety stays compact and well-branched from the base. Instead of growing tall and sparse, it forms a tidy clump that looks intentional from every angle. That structure makes it especially useful toward the front or middle of borders and in containers where shape matters just as much as bloom.

Rock Candy® Ruby prefers full sun and well-drained soil and performs best when conditions aren’t overly rich. Once established, it handles heat and short dry spells with ease. Good drainage—especially in winter—is the key to long-term success.

Why We Like It (Our Trials)

At Garden Delivery, Rock Candy® Ruby has proven to be one of the most consistent compact penstemons in our trials. It bloomed evenly, held its shape through the season, and didn’t thin out or flop. The flower color stayed rich and vibrant without fading quickly.

We also like how easy it is to design with. The ruby-red tones pair beautifully with silvers, blues, and softer pastels, and pollinators find the flowers quickly. For gardeners who want bold color in a smaller footprint, this variety delivers.

Rock Candy® Ruby vs. Other Penstemons

Rock Candy® Ruby brings rich, saturated color and a compact, highly controlled form. Compared to Rock Candy® Blue, Ruby reads noticeably warmer and deeper, giving it more visual weight in the garden. When set beside Red Riding Hood, Ruby trades height and vertical drama for a tighter, more uniform habit that fits smaller spaces with ease. It doesn’t offer the season-long foliage contrast of Husker Red, but it also doesn’t need it—the flower color carries the plant on its own. That compact structure keeps the color concentrated where it matters, without sprawl or thinning. Rock Candy® Ruby should be used when gardeners want bold, polished color that stays exactly where they put it.