Know your shrubs

Hydrangeas, sorted out

"Hydrangea" is really four different shrubs wearing the same name tag — and in Minnesota, knowing which one you have is the difference between an armload of blooms and a bare green bush. Here's the family, sorted.

Panicle hydrangeas — the sure thing

Cone-shaped flower heads, tough as nails, and the most cold-hardy of the bunch. Panicles like Limelight, Quick Fire, and Bobo bloom on new wood — the growth they put on each spring — so even a brutal winter can't steal the flower buds. They take more sun than any other hydrangea, and their blooms age from white through lime to rosy pink. If you want guaranteed flowers in Minnesota, start here.

Smooth hydrangeas — the native classic

Round, snowball-white heads on a shrub native to North America — Annabelle is the one your grandmother grew. Also blooms on new wood, so it's winter-proof, and it tolerates more shade than panicles. Cut it back hard in early spring and it comes back swinging.

Bigleaf hydrangeas — the beautiful heartbreaker

These are the florist-style mopheads whose color you can steer with soil chemistry: acidic soil frees up aluminum and turns them blue, alkaline soil turns them pink (our soil pH guide covers how to nudge that). The catch: most bigleafs set flower buds on old wood — last year's stems — and in our winters those buds routinely freeze. That's the number one reason a lush, healthy hydrangea never blooms. Reblooming types like Endless Summer hedge the bet by also flowering on new wood, but even those bloom lighter here than the catalog photos promise.

Oakleaf hydrangeas — the foliage play

Named for their oak-shaped leaves, which turn wine-red in fall — honestly worth growing for the foliage alone. Cone-shaped white blooms on old wood. They're marginal in our zone, so give them a sheltered spot out of winter wind and consider the blooms a bonus.