White Knight Hydrangea

White Knight Hydrangea (Hydrangea macrophylla 'White Knight') delivers the classic mophead hydrangea moment in guaranteed white: full rounded flower heads that open cream, hold pure white through summer, and age to soft green. Because white mopheads carry no colour pigment, soil pH cannot turn them pink or blue, so the display is identical in every garden. It grows to a lush 1.5m by 1.5m and thrives in those bright, shaded spots where gardens usually give up.

Why you'll love it

• White that stays white. No pH lottery: the blooms are white in Perth sand, Brisbane clay and everywhere between.
• Flowers by the armload. Big mophead blooms from late spring through summer, superb for cutting fresh and better again dried.
• Made for shade. Morning sun and afternoon shade, the aspect that defeats most flowering shrubs, is exactly its brief.
• A cool presence in hot months. Massed white hydrangeas visually drop the temperature of a summer garden like nothing else.
• Classic scale. At 1.5m it fills the space under high windows and along shaded fences perfectly.

Where it works best

Mass planting. Plant 1m apart along a shaded fence or south facing wall for a continuous white border; three to five plants make the statement.

Feature planting in small gardens. One shrub lights up a dim corner from spring to autumn.

Pots. A 40cm to 50cm pot on a shaded veranda or bright balcony suits it for years.

Growing White Knight Hydrangea in Australia

Position and climate. Morning sun with afternoon shade in most of the country; more sun is workable in cool mountain gardens. It performs in subtropical, warm temperate and cool temperate climates and is fully frost hardy, dying back tidily and reshooting in spring where winters bite.

Soil. Rich, moist and well drained. Compost generously, mulch 75mm deep, and remember the shallow roots dry out first in a heat wave.

Water and feed. Hydrangea means water: deep drinks twice a week through summer, more in heat spikes, especially in pots. Feed with a controlled release fertiliser in spring.

Pruning. In late winter cut stems that flowered back to a strong pair of buds and remove the oldest canes at the base. Unlike Annabelle it flowers on old wood, so never shear the whole bush to the ground.

What to expect when it arrives

White Knight ships in 200mm pots in packs of 6, in stock now, with 250mm packs of 3 grown to order and shown as backorder (we confirm timing with you first). The packs are sized for instant massed borders, and 200mm plants typically flower their first summer. Delivery is Australia wide, from $29.95, with a minimum order of $300 before delivery, and every plant carries our 30 day healthy plant guarantee.

Plant care guides and related reading

• Browse the full hydrangea range
• More plants for partial shade
• Plants proven in pots

Common questions

Can I turn the flowers blue or pink?

Not this one. White mopheads have no pigment for soil chemistry to shift, which is exactly why designers use them: the scheme survives every soil type.

Why did I get no flowers this year?

Almost always winter pruning that removed the old wood carrying the buds, or a late frost on early shoots. Prune only spent stems to a bud pair and flowering returns next season.

Why do the blooms flop in the afternoon?

Thirst, usually theatrical rather than fatal. A deep evening soak stands them back up by morning; consistent mulch and watering prevents the daily drama.

Is it safe around pets?

No. Hydrangea leaves and flowers are toxic to cats and dogs if eaten, so plant it away from committed chewers or choose from our pet safe range for those spots.