Endless Summer® Hydrangea

The Hydrangea That Changed Everything

Endless Summer® Hydrangea (Hydrangea macrophylla 'Bailmer') was the first bigleaf hydrangea proven to rebloom reliably on both old and new wood — a breakthrough that transformed the hydrangea market when it was introduced. Before Endless Summer®, bigleaf hydrangeas were notoriously unreliable bloomers in cold climates because a single late frost could wipe out the old wood that carried next season’s flower buds. Endless Summer® solved that problem by blooming on new wood as well, delivering large, mophead flower clusters from spring through fall regardless of winter dieback. Its color-changing ability — blue in acidic soil, pink in alkaline soil — adds another dimension of personalization that no other flowering shrub can match.

What Makes Endless Summer® Different

• Reblooms on old AND new wood — the original breakthrough; blooms reliably even after harsh winters that kill old wood; spring through fall bloom season
• Color changes with soil pH — blue flowers in acidic soil (pH below 6.0); pink flowers in alkaline soil (pH above 7.0); lavender-purple in neutral soil; you control the color
• Large mophead flower clusters — full, rounded blooms up to 8–10 inches across; one of the most dramatic flower displays of any shrub
• Cold-hardy for a bigleaf hydrangea — hardy to zone 4; far more cold-tolerant than traditional bigleaf hydrangeas
• Excellent cut flower — blooms hold well in fresh arrangements and dry beautifully for long-lasting dried arrangements
• Pollinator magnet — large flower heads attract butterflies and beneficial insects throughout the bloom season

Hardiness & Growing Zones

• USDA Hardiness Zones: 4–9
• Zones 4–5: Hardy in-ground; may die back to the ground in severe winters but regrows and reblooms on new wood in spring; mulch heavily around the base before first frost to protect roots
• Zones 6–7: Ideal conditions; vigorous growth with prolific reblooming from spring through fall on both old and new wood
• Zones 8–9: Thrives with morning sun and afternoon shade; avoid full western sun exposure in the hottest climates; provide consistent moisture during summer heat
• Sunlight: Morning sun with afternoon shade (ideal); tolerates full sun in cooler climates with consistent moisture; avoid full afternoon sun in zones 7+
• Soil: Moist, well-drained, rich in organic matter; consistent moisture is key to prolific blooming
• Mature size: 3–5 ft tall × 3–5 ft wide
• Bloom time: Spring through fall (May–October in most zones)

How to Change the Flower Color

Flower color is determined by aluminum availability in the soil, which is controlled by soil pH. To achieve blue flowers: lower soil pH to below 6.0 by applying aluminum sulfate or sulfur; this makes aluminum available to the plant. To achieve pink flowers: raise soil pH above 7.0 by applying garden lime; this locks aluminum out of the plant. White-flowered varieties do not change color. Note: color change takes time — results may not be visible until the following bloom season.

Planting & Care Tips

Plant in moist, well-drained soil with good organic matter. Water deeply and consistently — bigleaf hydrangeas wilt dramatically in drought but recover quickly with water. Mulch 2–3 inches around the base to retain moisture and keep roots cool. Fertilize once in early spring with a balanced slow-release fertilizer; avoid high-nitrogen fertilizers, which promote foliage over flowers. Prune lightly after the first bloom flush to encourage rebloom — remove spent flower heads just below the bloom. Avoid heavy pruning in fall, which removes next year’s old-wood buds.

Available Options

• 1–2 ft. (2 Gallon) — Single — well-rooted young plant; most economical
• 2–3 ft. (3 Gallon) — Single — larger specimen; faster to full bloom display
• 2 Gallon — Single — established root system; great value
• 3 Gallon — Single — most established single plant; may bloom first season
• 3 Gallon — 4-Pack — four plants at a value price; ideal for mass planting, hedges, or borders