Nannyberry

Size, growth and what to expect

Nannyberry's half-inch oval fruits hang in clusters and turn from green through yellow and pink to blue-black in September, sweet and edible with a single flat stone. It grows at a medium pace, roughly a foot and a half a year in its youth on an average site, which is the rate our growth estimator uses for it. It makes a multi-stemmed shrub or small tree of 15 to 18 feet and 8 to 10 feet wide, leggy at the base and suckering.

The flowers come in late May in flat-topped creamy clusters 3 to 4 inches across. Cedar waxwings, brown thrashers, ruffed grouse, chipmunks and red squirrels take the fruit. The USDA Plant Guide lists sheepberry among its names and notes that the ripe fruit smells of wet sheep's wool as it rots.

It grows wild from New Brunswick and Quebec west to Saskatchewan and south to Colorado, Nebraska, West Virginia and Pennsylvania, in low woods, swamp borders and rich valleys near streams. It transplants easily.

How to grow Nannyberry

Nannyberry grows in sun, part shade or shade, on dry, average or wet ground, and it is not fussy about soil. Sun brings the heaviest flowering and fruit. It reads as a small tree at full size, so leave 8 feet from a building and set a hedgerow 6 to 8 feet apart.

Plant during the dormant season. Saplings arrive bare-root or potted. Open a hole twice the root spread, hold the crown at the soil surface, put back the soil you dug, and lay mulch short of the stems. It stands without a stake. Seed has a double dormancy. It roots during about five months of warm, damp conditions, and then three months of cold lets the shoot grow. Sow cleaned seed outdoors in spring or early summer, half an inch deep, and seedlings come up the following spring.

Water weekly through the first summer in dry stretches. Deer browse young viburnums hard, so cage new plants until they clear browse height, and check for voles under winter mulch. Prune right after flowering, because next spring's buds form on this year's wood.

For fruit, plant more than one seedling, since viburnums set far better with a second, unrelated plant nearby. Cut suckers out for a single-stemmed tree. Powdery mildew whitens leaves late in summer in still, shady spots, which looks poor and does little harm. In the Northeast and Great Lakes, watch for viburnum leaf beetle.