It’s time for Mother Nature to push the old fellow aside and reveal her softer side with a bountiful and beautiful spring season.
Old Man Winter seems unwilling to relinquish his grip this season. Although I welcomed our protective snowy mulch during the bitter cold days of winter, I grow weary of winter white and yearn for springtime flowers and soft green foliage bursting forth from seemingly lifeless twigs. It’s time for Mother Nature to push the old fellow aside and reveal her softer side with a bountiful and beautiful spring season.
Gratefully, snowy accumulations tend to disappear quickly at this time of year, and with the official arrival of spring only a few days away, more springtime miracles are beginning to emerge. The sunny yellow blossoms of witch hazel continue to brighten even the gloomiest days, its feathery clusters still dazzling more than a month after they first burst forth. Along my back walkway, tiny purplish-pink bells dotted among the dark green, needlelike foliage of a winter heath, Erica "December Red," offer a welcome touch of color. In a sheltered corner, dainty blossoms of glistening white snowdrops dangle from delicate stems. Nearby, the plump buds of a Lenten rose (Helleborus orientalis) should unfold any day now to reveal a bouquet of mauve saucer-shaped blossoms. Despite the chill in the air, the arrival of springtime is just around the corner.
March is the ideal time to begin the process of selective pruning to produce balance, symmetry, direct growth or rejuvenate sparse or overgrown shrubs. Regular pruning will improve the overall appearance of nearly all woody plants since few grow with perfect shapes and even when selected appropriately for their allotted space, most benefit from an occasional trim to look their best.
There is an old adage that suggests that one should prune whenever the pruning shears is sharp. Although light pruning in any season is unlikely to cause permanent harm to an established tree or shrub, the timing and magnitude of the pruning process will greatly influence the growth and flowering of most plants.
Plants produce food reserves at season’s end to help them survive the winter months and to initiate growth in spring. Reducing the number of branches and buds prior to emergence of flowers and foliage leaves more energy for the remaining shoots and promotes especially vigorous growth in spring.
One drawback to pruning at this time of year is the removal of this season’s flowers. The flower buds of spring-blooming delights are normally set the previous year on what is termed “old wood.” Severe pruning, just before new growth begins, will significantly reduce their flowering, but I am often willing to sacrifice those fleeting blossoms to rejuvenate an overgrown tree or shrub. It is considerably easier to view the architecture of deciduous woody plants while they are still dormant and to observe damaged, diseased, or crossed branches. Crabapple trees are particularly vigorous and established trees require annual pruning to thin out interior branches. Plums and cherries, dogwoods, magnolias, azaleas and rhododendrons all benefit from periodic trimming. Bring a few of the pruned branches indoors to force into early bloom, but if you do not wish to sacrifice those lovely blossoms, prune spring bloomers immediately after they finish flowering.
Ornamental shrubs grown primarily for their foliage or their colorful twigs will produce better color and larger leaves on new growth. Red- and yellow-twigged dogwoods and purple smokebushes can be drastically pruned as their leaf buds swell and may even be cut down to the ground to promote vigorous new brightly colored stems or leaves.
Trees and shrubs that flower during the summer months (late June or after) tend to bloom on “new wood.” Spring pruning stimulates vigorous new growth and greater flower production for butterfly bush, sweet pepperbush (Clethra), Rose of Sharon, and Peegee Hydrangea. Butterfly bushes, in particular, often become leggy and unattractive when allowed to grow unrestrained; cut back these vigorous shrubs to 12 to 18 inches tall. The snowball hydrangea, ‘Annabelle’, will produce huge white spherical trusses if severely pruned each spring.
Our blue and pink mophead hydrangeas are exceptions to these pruning guidelines. Although these shrubs produce their blossoms later in the season, their flower buds are formed on “old wood” near the ends of the branches. Winter freezing or desiccation of their buds is often the primary cause for sporadic bloom, but substantial fall or spring pruning will eliminate a majority of the flowers. Thin out stems of older shrubs to allow light and air to reach the interior of the plant and remove dead branches only after new leaves fully emerge. Recent introductions, including H. ‘Endless Summer’, bloom on both old and new wood, ensuring flowers despite adverse weather conditions or untimely pruning.
Many suckering or overgrown shrubs will benefit from a process known as renewal pruning. Forsythia, lilac, quince, Spiraea, Virburnum, Potentilla, and Weigela, are just a few of the shrubs that may become a jungle of branches with diminished flower production. A radical pruning, including lopping the oldest stems to 1 foot or even down to the ground, is recommended. If approximately one-third of the stems are removed each year, an overgrown specimen can be completely rejuvenated over a three-year period without sacrificing the majority of flowers. Prune during late winter or immediately after flowering.
Learning to prune effectively requires practice. A poor pruning job is analogous to giving a bad haircut. Barring the infiltration of disease, the tree or shrub will nearly always recover, re-grow, and be ready for another trim later in the season or the following year allowing for correction of any gross mistakes.
Suzanne Mahler is an avid gardener, photographer and lecturer who has been developing the 1.5-acre property surrounding her home in Hanover for more than 30 years. Her weekly gardening column 'Green Thumbs Up' has appeared in Community Newspapers for more than a decade. She is a member of two local garden clubs, past President of the New England Daylily Society, an overseer for the Massachusetts Horticultural Society and is employed at two garden centers.