Tag Archives: Spirea

Help…when do I prune spring flowering shrubs and trees?

5-15-14 blog new shoots on Lilac

The show is over…spring blooming shrubs and trees have put on their much appreciated display.  With blossoms just passing by, your plant is already planning for spring 2015.  It is hard for us humans to remember that this is the right time to prune those same plants.  Timing your pruning correctly will positively manage the shape and health of the plant as well as promote their bloom performance in the years to come.  As a general rule of thumb: don’t prune spring blooming shrubs and trees more than a month or so after they finish blooming unless you are willing to sacrifice some bloom. Plants like Forsythia will now start developing their 2015 flower buds so waiting too long to prune will eliminate some of next year’s display.

Spring bloomers like Forsythia and Lilacs renew themselves by sending up new stems at or near ground level each year. As plants age, older stems begin to crowd each other and the plant will flower less than desired.  Cutting away some old stems will make room for new vigorous ones to take their place and gives the new shoots time to grow and bud up this year for flowers next year.  Making selective pruning cuts to older stems promotes the overall good health and vigor of the plant.  This is also a good pruning approach for Red Twig Dogwood and other multiple stem shrubs like Spirea. Do this type of thinning now.

For more bushy shrubs with side branches off of a main trunk, like Azaleas, Rhododendrons, Pieris, and Kalmias, they can use some shaping after they bloom too.  Consider their current shape and make some cuts inside the plant to increase air circulation and sunlight penetration.  All too often, these shrubby plants get too dense and the flowering decreases.  Shrubs that have been pruned incorrectly in the past or outgrow their location may require more radical considerations.  This is often called rejuvenation or renovation pruning.  Some mature or neglected shrubs may need several seasons of renovation pruning to bring them back into scale with the landscape and restore their full beauty.

To do any of this pruning, sometimes you need courage, sometimes you need coaching and sometimes you need a professional to take charge.  We’re available if you need help.