Hydrangeas

Hydrangeas do a job few other shrubs manage: they hold large, structural flower heads through the hottest weeks of summer and into autumn, in positions that get very little direct sun. That makes them the shrub of choice for a south-facing bed, a shaded courtyard, the strip beside a fence that never quite warms up, or the bed under an established deciduous tree, where they will need extra water. Buy them if you have a spot that is bright but sheltered from midday and afternoon sun, and you want mass and colour rather than fine detail. They also hold their shape in large pots.

The range here splits into two groups that behave differently. The bigleaf types are the familiar mopheads and lacecaps. Hydrangea macrophylla is the standard, and it is the one whose flower colour responds to soil, turning blue in acid soil and pink in alkaline. It is stocked across four sizes, from a 175mm squat pot through 200mm and 300mm up to 500mm plants. Jogasaki is a lacecap with doubled florets around a flat centre, sold as a 140mm starter from $21.95. Runaway Bride is different again: it flowers along the length of long, arching stems rather than only at the tips, so it suits a raised bed edge or a wide pot where it can spill over the rim. The panicle group, Candlelight and Hercules, carries cone-shaped heads on stiffer stems and takes more sun than the bigleaf types. Diamond Rouge and Sundae Fraise are panicle types too, opening pale and ageing to pink and red. For size straight away, Strawberries and Cream, Tuxedo Pink and Oriental Lace are stocked only as advanced 330mm plants, and the Assorted line runs from 140mm pots to 200L specimens.

Position matters more here than anything you do later, and the mistake to avoid is hot afternoon sun. A hydrangea against a west-facing wall or out in open lawn wilts flat every hot afternoon, scorches brown around the leaf margins and flower edges, and either dies in its first summer or sits stunted for years. Morning sun with afternoon shade is the target; in a cool southern district they carry more sun if the soil never dries out, but through a hot inland or subtropical summer it is a requirement. Full shade is workable and gives you fewer flowers. Improve the soil with compost before planting, mulch to about 75mm to keep the root zone cool, and water deeply twice a week through summer rather than a light sprinkle each day. Pruning depends on the group: bigleaf types set next season's buds on old wood, so cut them back straight after flowering and leave them alone in winter, or you will cut off the flowers. Panicle types flower on new wood and can be shortened hard in late winter.

A shaded bed keeps working through the year if you back them up: camellias and gardenias take similar conditions and flower either side of the hydrangea season. For colour across the wider garden, see flowering plants, or work through shop all plants to build a full order. Every order ships farm-direct with flat $99 delivery across QLD, NSW, VIC, SA, ACT and WA, a $399 minimum order, and the 30-Day Healthy Plant Guarantee.

New to these plants? Read our guide: Hydrangea care, pruning and flower colour.