These articles are written to apply to the northeastern
corner of Illinois. Problems and timing may not apply outside of this
area. |
Don't Neglect Pruning Shrubs
May 20, 1999
While often neglected, pruning is an important part of the maintenance
of deciduous shrubs. Not only will pruning help control shrub size and
attractiveness, it may also help keep shrubs flowering on a regular basis.
Pruning deciduous shrubs is a fairly basic process with just a few basic
guidelines to follow.
The first question often asked is when to prune? Late winter and spring
are good times, with timing of flowering a consideration. For shrubs that
have already bloomed, or are just starting now, flower buds formed last
season. Prune soon after flowering. Those shrubs that bloom in mid to
late summer flower on new wood produced this season thus are best pruned
while dormant.
The second question is how to prune. There are two primary methods, renewal
pruning and rejuvenation. Renewal pruning involves cutting out older stems
near the base, which then promotes younger stems and new growth. Remaining
stems may need some trimming back into a desirable shape. Some shrubs
best pruned by the renewal method include lilacs, red twig and yellow
twig dogwood, arrowwood viburnum, forsythia, kerria, deutzia, mockorange,
and weigela. Most of these are best pruned right after they flower.
Rejuvenation pruning involves cutting all stems down to near ground level;
leaving short stubs. This method is useful when a shrub has become overgrown
with many stems massed together. Among the shrubs that respond well to rejuvenation include Anthony Waterer
spirea, honeysuckle, beautybush, indian currant, snowberry, and privet.
Larger, older shrubs should not be rejuvenated in late spring or summer.
Early spring is preferred for most.
After either method, new growth can be pruned back to help keep shrubs
the size and shape desired. With hedges such as privet, prune them so
that the lower portions are wider than the upper, so all leaves get equal
light. This will help prevent the lower portions from dying out. Avoid
pruning the side perpendicular to the ground or angling in toward the
base. Hedges in poor shape should be rejuvenated and the new growth then
pruned properly. |