Limelight Hydrangea

There is a stretch in September when a single Limelight carries lime green, cream, pink, and burgundy at the same time, because the panicles age at different rates and none of them drop. Hydrangea paniculata 'Limelight' grows 6 to 8 feet tall and wide, hardy from Zone 3 through Zone 9, in full sun to part sun with at least four hours of direct light. It reaches full size in three or four seasons.

The show starts in midsummer with big dense cones of soft chartreuse, a color almost nothing else in the garden produces. They hold that green for weeks before fading to cream, and the pink arrives with the first cool nights.

Cut them at any stage and they last. Fresh in a vase they hold for a week or more, and left alone on the plant they dry standing up and stay through the winter with snow caught in them. How much pink you get depends on where you garden. The color change is driven by cool nights, so northern gardens color up strongly while warmer southern gardens tend to hold cream and soft blush instead of turning burgundy.

Panicle hydrangeas flower on new wood, so the buds form in spring on the current season's growth and a hard winter cannot take the display. That is why they bloom reliably in Zone 3 where the bigleaf types will not, and soil pH does not affect the color. Cut back by about a third in late winter to keep the stems strong enough to carry the heads. It handles more sun, cold, and drought than any other hydrangea group, and wants well-drained soil.