Q. How can I hedge boxwood?
“Boxwood (Buxus spp.) make very good compact hedges. 'Winter Green' and 'Green Beauty' are good cultivar choices. For a smaller hedge, there are dwarf varieties that could be used - 'Morris Midget' and 'Wee Willie'®. These are English boxwoods. They grow well in USDA Zones 6-8. Korean boxwoods are hardier (to USDA Zone. 4).
To make a nice hedge plant the shrubs quite close together (about half the distance of the mature bush width). Apply a layer of mulch after planting as boxwood have a shallow root system. If your box are recently planted then wait a year or so before beginning to prune, although it is better to start early rather than letting the plants get too big.
When your plants are young then just pinch back the growing tips to produce a bushier shrub If your box wood is already fully established then you may need to thin the plants to allow some light to enter the center of the plant. Cut back a few of the center branches each year back to the main trunk or a lateral branch. Then shear the outside to the desired height using a hand or electric shearer. Use a string level at the desired height to get a level hedge.
It is advised to trim the hedge into a pyramidal shape, i. e with the bottom wider than the top. This allows more light to each the bottom of the hedge thus avoiding a dead zone along the bottom of the hedge. The best time to prune hedges is in late winter although the work can be done any time, except late fall.
Good cultural practices are important in reducing box blight problems. Too much fertilizer and top watering in particular can lead to problems. The American Boxwood Society, as you can imagine, keeps a very close eye on this issue and they recommend this research by the University of Vermont regarding disease resistant cultivars.
Courtesy of NYBG Plant Information