A slow-growing, narrow-leaved evergreen, juniper (Juniperus spp.), is widely planted near residential foundations, as hedgerows or as landscape specimens. It is slow-growing and generally requires very little pruning. Growers should prune juniper in early spring to give new growth time to harden off before winter.
To keep junipers looking their best, prune out dead or diseased wood. Cut back to a lateral branch in active growth containing green leaves. Junipers cut back to bare wood do not regrow where the cut was made. The interior portion of all types of juniper---prostrate, shrub and columnar---does not produce new growth. Therefore, do not make any pruning cuts into the area of the plant's interior where you find no new green growth.
Pruning to Control Size
Pruning a juniper planted in a small space can control its size. Do this by tip-pruning its branches yearly. Cut back 20 percent of the plant's new growth, always making the cut just above an actively growing lateral branch containing green leaves. Do not make any cuts into the center "dead zone" of the juniper, as they seldom regrow from cuts made back to bare wood containing no actively growing branches.
Prune in Unnatural Shape
Growers can train junipers into unnatural shapes by shearing the entire plant. Although the most extensive pruning of this type should be done in early spring, light shearing can be done for shaping through midsummer. Sheared junipers require consistent, regular pruning to maintain their unnatural shape. One drawback of this method is that the plant produces a lot of growth at the pruning cuts, shading the interior of the plant and creating a thin shell of foliage with a bare center. Shearing also makes junipers more susceptible to winter dieback.