SCIENTIFIC NAME: Hydrangea arborescens 'Haas' Halo'

COMMON NAME: Haas Halo Smooth Hydrangea

GARDEN SIZE: 4 to 6 feet tall by 3 to 5 feet wide

GROWTH RATE: Fast

USDA ZONE: 3 to 9

EXPOSURE: Full sun to partial shade; prefers some afternoon protection here in Tennessee.

WATER & SOIL: Prefers moist, well-drained soils high in organic matter. Tolerates clay, loam, sand, or shallow rocky soils with neutral to acidic pH. Consistent moisture is needed, especially in full sun.

HABIT (FORM): Mounding, woody, deciduous shrub with stout, upright stems

FOLIAGE: Deciduous; leathery blue-green leaves, 3–6" long, serrated margins

FLOWER COLOR: White with greenish fertile centers

FRAGRANCE: Light

BLOOM FORM: Lacecap, up to 8" across with sterile outer florets and fertile inner florets

BLOOM TIME: Mid-June through early July, occasionally extending later

PLANT ORIGIN: Eastern United States — from New York south to Florida, and west to Iowa, Missouri, Oklahoma, and Louisiana (including Tennessee).

WILDLIFE SUPPORT: Host plant for local butterflies and moths, and food source for pollinators, birds, and small mammals. Supplies shelter and nesting sites.

FERTILIZING: Low maintenance; typically requires no regular feeding. Apply organic compost or a balanced slow-release fertilizer in early spring only if growth or flowering is weak.

PRUNING: Blooms on new wood; prune in late winter or early spring before new growth begins to encourage vigorous flowering and shape.

TOXICITY FLAGS: Poisonous to humans, cats, dogs, and horses if ingested.

USES: Borders, mass plantings, naturalized areas, slopes, woodland gardens, rain gardens, and pollinator gardens