Nannyberry (Viburnum lentago) is a versatile shrub that grows in dry, moist or wet soil and does well in both full and partial sun. It has white flowers in mid-spring followed by bluish-black fruit. The foliage is a glossy green that turns orange, yellow and red in the fall. Nannyberry has a leggy form and can be pruned into tree form, but its slow growth rate requires minimal pruning.
Use hand pruners to cut limbs up to 1/2 inch in diameter, lopping shears for limbs up to 1 inch in diameter, and a pruning saw for larger branches. Cut limbs at a 30 degree angle at a bud or joint.
Remove dead, damaged or diseased limbs and branches. Signs of diseased limbs include cankers, split wood, peeling bark and dying leaves.
Thin out and open up the interior of the plant. Cut older limbs and branches back to a main branch or down to ground level.
Remove elongated or wayward limbs that spoil the shape of the plant.
Choose an upright straight branch of the plant to serve as the trunk of the tree shape you will create. Remove the rest of the limbs and branches growing from the ground, so that the branch for the main trunk is clear of ground level foliage.
Determine how high you want the canopy of the tree. Remove the limbs and branches growing on the lower part of the trunk below the canopy so that the trunk is smooth. Step back often to view the shape and proportion of the tree until you have achieved the form you want.
Follow the instructions laid out in "Shrub Form" Steps 2, 3 and 4 to remove dead, diseased and damaged limbs, thin out older growth and shape the plant.