Arrowwood viburnum (Viburnum dentatum) makes an ideal formal hedge or informal shrub. Arrowwood viburnum develops a round form with arching branches. Most shrubs grow up to 8 feet tall and 10 feet wide. The glossy, green foliage produces white, flat-topped flowers in spring followed by blue berry-like fruit in the summer. The foliage fades to yellow and the flower clusters turn reddish purple in fall. As a native plant, arrowwood viburnum requires less maintenance than non-native plants, but it does require pruning suckers that develop from the base of the shrub.
Plant arrowwood viburnum in spring or fall in a sunny or partially shaded area large enough to accommodate the plant at maturity. Arrowood viburnum needs consistently moist soil with average fertility but grows in a variety of soils, including alkaline.
Spread a 3- to 4-inch layer of mulch around the base of the arrowwood viburnum that tapers off toward the trunk. Mulches of shredded pine or hemlock keep the roots cool and moist, but too much mulch piled against the trunk creates entry points for insects and diseases and encourages the bark to rot.
Water newly planted arrowwood viburnum deeply until it becomes established. A mature viburnum typically only requires 1 gallon of water twice a week during periods of drought or before the ground freezes in fall.
Feed the shrub annually with bagged sludge, a granular fertilizer combined with a slow-release form of nitrogen or compost. Use a 10-10-10 fertilizer on the soil from the base of the plant to 1 1/2 feet past the drip line in fall.
Prune arrowwood viburnum in spring after the shrub blossoms to promote a more compact form. Cut to the ground old, weak or leggy stems before new growth emerges on mature shrubs.
Watch for signs of crown gall, leaf spot, powdery mildew and shoot blight. Crown gall causes knots to form on the lower stems. Leaf spot causes round, water-soaked spots of the leaf surface. Powdery mildew produces a white dust on the undersides of leaves. Shoot blight causes brown, decayed spots at the leaf margins. Remove and destroy all infected leaves.