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FeedWinter Fruits
Prune wisely to encourage bountiful berries
My visit to the New York Botanical Gardens in mid-October offered a memorable, if humbling, teaching moment courtesy of a viburnum, commonly called highbush cranberry. It came just to my waist. The slender gray branches were covered with dense foliage shaped a bit like maple leaves and turning crimson at the tips. Clusters of luminous, pellet-sized berries hung from drooping stems to rest on the leaves. Everything about the shrub was graceful and balanced—the shape and growth habit, the long stems, the colors.
As he admired the fine shrub with me, my husband asked why I didn’t grow that variety. While stooping to read the plant label, I informed him that this particular viburnum most certainly wouldn’t be hardy back home in Zone 4, and that, in fact, most of the plants I coveted in this garden were really meant for warmer regions.
The label brought me up short: “viburnum trilobum ‘Wentworth’.” Blushing until my face was almost as red as the cranberries, I confessed that this was the same ‘Wentworth’ I planted years ago between twin v. lantana ‘Mohican’ bushes, the same plant that I constantly cuss for its bland appearance and annoying insistence on striving for a height of 10 to 12 feet.
It seems that my own ham-handed pruning is what’s the matter with my ‘Wentworth’, not the plant itself. If I’d given it more room (thus obviating the need for pruning), or learned how to prune it correctly to keep it small without compromising its berry production or its natural shape, I’d have a shrub like the one on display in the New York Botanical Gardens. Moreover, I definitely would not have planted four plants (a hemlock in addition to the viburnums) for a privacy screen when any one of them would have done the job better (i.e., more beautifully) alone.
I should have allowed selected viburnum limbs to follow their flowering with berries.
Instead I made a lot of unnecessary work for myself and with less attractive results. Every year I trim the lower branches of the Canadian hemlock to make room for the encroaching viburnums, all three of which I heavily prune after they’ve flowered in spring. Because I prefer the blue-green leaves of ‘Mohican’ to the bright green ones of ‘Wentworth’, the latter has received the roughest treatment. I should have thinned ‘Wentworth’ and allowed a few carefully selected limbs to follow their flowering with berries. But no. I sheared the shrub to a 4-foot mound, lopping off all the creamy lace-cap flowers once they were finished and removing all potential berries.
Little did I know that not only do the fruits of ‘Wentworth’ range in color from yellow to red, they are also edible—just the thing for holiday cranberry sauce and great for holiday decorating, too, whether left on the branches to light up the winter garden or wired to a wreath. I should mention that ‘Wentworth’ viburnums can be sheared to make a nice hedge, but cutting off the flowers will cost you the berries.
I left New York chastened but eager to nurse my own shrubs back to berry-producing form. V. lantana ‘Mohican’ is more compact than ‘Wentworth’, topping out at a mere 6 to 8 feet. Its berries, also reddish orange, eventually turn to black. It too is an excellent provider for holiday decorating. For this purpose, I also love junipers (for their blue-gray berries), cutting them for bundles that I heap on the fireplace mantel and stuff into large glass vases; creeping cotoneaster, whose red berries also last all winter and don’t mind staying indoors for a few days; and porcelain berry, which gets its common name from its unique turquoise berries.
Last year my friend Lynn Brush added a second berry-producing vine to the holiday collection. Brush is a master carpenter and stone mason who moonlights as “the bittersweet guy,” harvesting American bittersweet in the wild and selling it to local garden centers. At the same time he may save the tree or shrub that this parasitic vine would eventually suck of its life.
This fall I decided that I must have a new pergola in my back garden and that Brush was the man to build it. He was off somewhere hunting for bittersweet, but eventually appeared with a pickup load of lumber for the pergola and bittersweet for me. Its red-orange berries last for years if you bring them indoors, but I’ve arranged my bittersweet on top of the new pergola instead. The long stems twine through the crossbeams, dangling their fat berry clusters like grapes, and make it easier to endure the wait until I can begin training living vines to take the bittersweet’s place.
Of course you don’t have to grow your own in order to have berries for holiday decorating. You can use the same bagged cranberries sold for making cranberry sauce, which make excellent topiaries when stuck with toothpicks to cover a foam form. Combine them with yellow kumquats, and add gardenia leaves at the top and bottom for a delightful holiday centerpiece.
Bonnie Blodgett publishes The Garden Letter and is writing a book about smell for Houghton Mifflin.
Prudent Pruning
Though early spring pruning may remove flower buds on spring-flowering shrubs like lilacs, late winter to early spring is generally an excellent time to prune. Plants are less brittle then and tissues are primed for renewal. Summer pruning suppresses sucker and foliage production. Fall pruning stimulates new growth that might not harden to survive the winter.Before pruning a shrub, you need to understand its growth habit and follow its lead: mounding (e.g., spireas), caning (forsythias), or tree-like (rhododendrons).
» Mounding: Relatively soft stems and leaves are easy to prune to a compact shape if you remove only the longest stems from well inside the shrub’s mass. Heading cuts made indiscriminately stimulate too-rapid re-growth from buds closest to the wound and unsightly clusters at the branch tips. Choose thinning cuts just above a bud instead to control where new growth occurs. Some mounding plants do tolerate heading (also called shearing) to maintain a hedge, so find out which kind you have before cutting away.
» Cane: Rejuvenate these shrubs by encouraging the growth of the freshest stems and removing the rest. Cut (or saw) old canes at ground level to stimulate new growth, and accentuate the shrub’s natural shape by also removing renegade or crisscrossing canes.
» Tree-like: Prune to open up the center and to let light into the shrub’s interior. To encourage new growth outward, make cuts at an angle away from the bud and just above it, taking care not to leave a long stub that could rot. Also remove crossing branches, any limbs touching the ground (these may root), and suckers originating from the roots
—B.B.
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