Mountain Fetterbush

Size, growth and what to expect

No source rates its growth, but the seedlings grow very slowly at first, so our growth estimator treats it as slow, about a foot a year. It forms a dense, rounded shrub 3 to 6 feet tall and about as wide.

Fragrant white urns open in upright clusters from late March to early May, and the show lasts 4 to 6 weeks. Native bees and bumble bees work the flowers. Next year's flower buds form in midsummer and stand out through the winter, growing creamier as spring nears. The capsules ripen in mid to late fall.

It grows wild from West Virginia and Virginia to North Carolina, Tennessee and northern Georgia. Its home is high balds, heath thickets and oak, pine and hemlock woods. In New England it grows wild only in Vermont, far north of its native range.

How to grow Mountain Fetterbush

Mountain fetterbush does best in part shade and takes nearly full sun. It needs a soil high in organic matter that drains very well but does not dry out. It prefers acid soil, though it takes more lime than most heaths. Shelter it from winter sun and sweeping wind, which burn the leaves, and keep it out of hot spots. Set plants 4 feet apart and keep them 3 feet from a wall. At its size it can go within 15 feet of overhead wires.

Saplings ship potted. It can be hard to transplant and to establish, so keep the root ball whole when you plant. Plant in early spring or fall, in a hole wider than the root ball and no deeper, and put the native soil back in. Mulch with pine needles or leaves, kept off the stems. The seed needs no chilling or other treatment. Sow it on the surface of a damp, fine mix at room temperature, under a clear cover in daylight. Most comes up within a month, and the seedlings grow very slowly at first.

Water weekly through the first two summers, so the soil does not dry out. Guard young plants from deer where they are common. It tolerates pruning, but next year's flower buds form in midsummer, so prune right after bloom. Cutting off the spent flowers brings more bloom the next year.

Mountain fetterbush carries both male and female parts in each flower, and small bees pollinate it. Its close relative Japanese pieris sets seed with its own pollen, so one plant should bear alone. A plant near Japanese pieris can cross with it, which is how the garden hybrid Brouwer's Beauty arose. Stem rot takes plants where drainage is poor. The leaves and flowers are highly poisonous if eaten.