Hydrangeas

Start with the type, not the color

Nearly every hydrangea problem traces back to treating them all the same. The two kinds on our bench want different things.

Panicle hydrangeas — cone-shaped flower heads, blooms on new wood. They take more sun than people expect, hold their stems up, and can be cut back hard in late winter. Bobo, Little Lime Punch and Puffer Fish are all panicles.

Oakleaf hydrangeas — big lobed leaves, blooms on old wood. They prefer a little shade, especially from the afternoon, and they set next summer’s flower buds during this summer. Ruby Slippers is our oakleaf.

Pruning, made simple

New wood, prune late winter. Old wood, prune right after it flowers.

If you cannot remember which one you have, do nothing. A hydrangea that is never pruned still blooms. A hydrangea pruned at the wrong moment does not.

Water

Hydrangea comes from hydor — water. The wilt you see at four o’clock on a July afternoon is usually the plant catching its breath, not an emergency; check again in the evening before you reach for the hose. If it is still flat at dusk, water deeply at the base rather than lightly over the top, and mulch to hold what you gave it.

Sun

Panicles will take full sun here and bloom better for it. Oakleafs are happier with morning sun and shelter from the worst of the afternoon. Neither one wants to bake against a west-facing brick wall.

About changing the color

Blue-to-pink color changing is a macrophylla trick — the mophead hydrangeas. None of the four above will do it, no matter what you put in the soil. Their color comes with age instead: white opening, pink or red finishing, and on Little Lime Punch, both at once.