Hydrangea macrophylla è un arbusto deciduo nella famiglia Hydrangeaceae, coltivato per le sue grandi e appariscenti teste di fiori.
Morning sun with afternoon shade is ideal; too much hot sun wilts and scorches, while deep shade reduces flowering. H. paniculata takes the most sun, H. quercifolia and macrophylla prefer part shade.
Keep the soil consistently moist — the name means 'water vessel' and the big leaves wilt quickly when dry. Mulch to retain moisture; water deeply in heat. Avoid waterlogging.
Rich, moisture-retentive but well-draining soil with plenty of organic matter. In H. macrophylla, soil pH alters flower colour (acidic = blue, alkaline = pink).
Cool to mild, hardy in the garden; most tolerate frost. Average to high humidity. Protect early growth from late frosts.
Feed in spring and early summer with a balanced fertilizer (or one for acid-loving plants if blue flowers are wanted). Avoid late-season high-nitrogen feeding.
Pruning depends on type: macrophylla/serrata flower on old wood (prune just after flowering), while paniculata/arborescens flower on new wood (prune in late winter). Mildly toxic if eaten (cyanogenic glycosides) — keep away from pets.