Invincibelle Limetta® Smooth hydrangea

Green flowers that stay green, on a smooth hydrangea small enough for a foundation bed. This Proven Winners® selection, Hydrangea arborescens 'NCHA8', grows 3 to 4 feet tall and wide in part shade with four to six hours of sun, mostly before midday. Hardy from Zone 3 through Zone 9, reaching full size in two or three seasons.

The flower heads open soft lime green in early summer, lighten toward white at peak, then settle back to green and hold that color into fall. Because smooth hydrangeas flower on new wood, deadheading spent heads brings a second flush later in the season.

The stems are strong enough to carry the flower heads upright, which is what makes a smooth hydrangea usable in a bed you look at rather than one you tie up.

Smooth hydrangea is the group that blooms most reliably in cold gardens. The buds form in spring on the current year's growth, so a hard freeze or a late frost cannot take the display, and it flowers in Zone 3 where the bigleaf types will not. Soil pH does not change the color. Cut back to about 18 inches in late winter to build a sturdy framework. It wants consistent moisture, tolerates wet ground, and prefers shade from midday on in hot climates.