Periods of lingering snow have formed a welcome blanket for shivering if drowsy flower buds this winter, and the snow has also provided a brilliant backdrop for big shrubs and small trees.
These “woodies” are at their least showy in deep winter, but they invite study of the textures and patterns of their bark along with the ornament of last year’s lingering pods and this year’s swelling buds. They catch the eye mostly, though, with their silhouettes in the landscape. The snow draws starker outlines.
I never tire of looking at a bottlebrush buckeye that sits on a hill about 30 feet from the kitchen window. It has grown in the past 20 years or more from a twig into a tall spreading shrub 15 feet high and 12 feet across. In leaf, it forms a fabulous screen of just the right scale. Now, it presents a pleasing tracery of charcoal gray branches.
It has reached maturity, stopped growing, for the most part, and rewarded patience with its little perfection. If I had been in a rush and planted a cedar or pine in its place, I would have been pleased for the first five years and fighting a giant thereafter. The world is full of trees that have outgrown their spaces and full of people trying to hack them back.
Hacking is bad, but pruning is good, or can be, if you know what you’re doing. This is the season for pruning many of the deciduous woodies, but if you don’t know why you’re pruning or what you’re pruning, then leave the plant alone. Nor should you assume that the guy who delivers your mulch knows how to prune.
If you prune in an arbitrary or excessive way, the plant can respond by growing a load of gangly and weak suckers — water sprouts — and you see this on badly pruned apple trees and crape myrtles.
When you get manic about pruning, you sometimes stop looking at the pleasing architecture of the plant and begin to see everything that is wrong: a rubbing branch, a stem growing inward, a water sprout, a broken twig. All these can be fixed through artful pruning. This month and next form a perfect period for this: The shrubs are dormant, they have yet to use energy in pushing new growth and, in their naked state, you can see the branch structure.
Anything that blooms between now and the end of June flowers on growth from last year, so each snip probably removes flower buds. This isn’t necessarily bad — a reduced flower display may be secondary to the restored vigor of a plant — but you run the risk of ruining the whole show of things such as wisterias, lilacs and rhododendrons.
Large shade trees should be left to professionals — the work is just too dangerous and potentially destructive — but winter is the time to see wounds, snags and dead branches that otherwise would be hidden in leaf.
Many people have an urge to cut back hard their mophead or lacecap hydrangea because of its dead and twiggy appearance, but you must leave it alone if you want a display in June. An old, congested one will benefit from the removal, in season, of entire canes, especially the oldest and least productive.
There is one common shrub that almost anyone can attack now with relative abandon: the rosebush.
Roses are inherently sickly, but the vigor of modern hybrids far outpaces their woes. A good winter prune will produce a plant with larger if fewer blooms, a more open habit and healthier foliage. A neglected rosebush may eventually grow to eight feet tall and as much across, producing a thicket of branches that are grudging in flower but full of thorns. An annual prune will keep the rose contained and floriferous — it’s much harder to reclaim one that has been allowed to think of itself as a tree.
I use heavy leather gloves and loppers to shield my hands against the thorns. Dead canes are removed entirely along with any suckers erupting from the soil. If there are two canes rubbing against each other, the weaker or misdirected one comes out. The object is to form a bush with an open center, a goblet of five or six canes. The canes that I keep are cut back from, say, four feet to 18 inches. The trick is to make your final cut (hand pruners are employed at this point) just above an outward facing bud. This ensures that the spring growth is away from the center of the bush to allow good air movement through the plant to minimize blackspot.
If you have utilitarian, landscape roses (Knock Out is the ubiquitous example), you can crudely prune them with hedging shears. This is quick and effective if you have planted several roses as a prickly ground cover, which is not a bad way to treat a slope in full sun.
Rambling roses are another beast entirely, and should not be cut back hard now. I have two trained laterally against a wire fence. After flowering in May, they continue to put out growth that would upset the groomed effect if left untended. I trim them continually, while telling myself that I’m not one of those victims of landscape impatience. I planted the right plant, you see, but not necessarily in the right place.
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