CAMBRIDGE — Hedges may well be the leading bone of contention between neighbors who otherwise could be great friends because of their shared love of gardening.

“I can’t see the water view because your hedge is too high!”
“Your hedge is so messy, it makes the whole neighborhood look bad!”
Disagreement between neighbors over the height and shape of a hedge can lead to a rankling hatred that poisons lives on both sides – a situation to avoid at all costs.

Once, I lived by a courtyard shared by five small houses, in a village in a far-off country across the sea. In the past, these had been fishermen’s cottages. Each had a small garden in front, giving onto the courtyard, and a gate at the end, just to keep things neat and private.
A woman of a certain age, who was not a neighbor, used to visit one who was. Every time she passed my gate, she’d snap off a stem or two of the climbing rose that I had trained over my gate.
“You need to prune these, they’re too tall!” she’d announce if I happened to be outside gardening. Sometimes, looking through a window from inside my house, I’d spot her “pruning,” even though I was indoors.

Behind her back, I called the unwelcome visitor “Colonel Prune” (in both senses of the word). To her face, I said: “Actually, I like them tall and bushy.”
A neighbor who lived all the way at the end of the courtyard, possibly the one Colonel Prune visited, complained to me, “I can’t see the road.” Personally, I’d rather see roses than cars parking and dogs peeing, I replied.
If you live in a town or community, there may be rules and regulations governing the height of hedges, so it’s a good idea to find out what they are before tempers flare. In the meantime, the following paragraphs will give you pointers on what to do and not do to keep your hedge uncontroversial and the neighbors pleasant.

Hedges can be formal or informal in style and composed of deciduous or evergreen shrubs and trees. Or a mixture. Why not? They may be as tall as a pine tree or as low as a stone wall. Their purpose is to act as a border, fence, screen or windbreak, or all of the above.
Plants made into hedges are usually chosen for their ability to hold a shape and form thick, entangled growth, from the ground up.
But some people prefer to employ a variety of native plants that will appeal to the birds and butterflies. Others want flowering shrubs, such as forsythia, rugosa rose, rose-of-Sharon, spirea and viburnum. Still others opt for a hedge that will decorate the landscape with berries – possibly edible ‑ in summer, fall and winter. It might include holly, elderberry, highbush cranberry and wax myrtle. These types of hedges tend to be informal, allowed to grow freely, with only an occasional pruning to keep the greenery within bounds.

Generally the hedges one sees in Dorchester County look fairly formal. They’re usually composed of evergreen plants. These may include privets, boxwoods, yews and arborvitae; but they can also be formed of hollies, junipers, pine, spruce and fir.
As for what pruning should be done now, it depends on the plants. Deciduous hedges should be pruned after the first strong growth of spring has slowed down, in May or June, then again in mid-summer, when secondary growth may need to be shaped.

To thicken the growth of coniferous trees such as pine and fir, pinch out half the “candle,” which is the new spring growth, when it’s about two inches long, usually in early June. Use your fingers, not shears.
Evergreens grow more slowly than some other hedge plants and should never be severely pruned. Pruning is not recommended at all for spruce. Yews can be given a light pruning in July.
Junipers, arborvitae, holly, boxwood, euonymous and abelia may be pruned before spring growth; privet, azaleas, forsythia and lilac after flowering. Clip out faded lilac blooms, too. Viburnum? Spring flowering species after flowering but summer flowering ones before spring growth.

What sort of shape should a hedge have? Like a pyramid: Much wider at the bottom than the top. An example from the University of Maryland’s Master Gardener Handbook: A hedge five feet tall could be 3-1/2 to four feet wide at the base, but one foot wide at the top. This shape lets the lower branches get enough light and air circulation to keep them healthy and leafy. If allowed to broaden at the top, the hedge loses its lower leaves and becomes leggy.

Many people shear their hedges with power clippers, giving them a hard, geometric shape. It’s fast but not always attractive, if you prefer the plants’ natural beauty, and not always healthy for the plants. If you repeatedly cut a hedge back hard, trying to return it to its original shape and size, it will become so dense and twiggy that it provides a perfect home for destructive insects, fungus and disease.
When shearing, leave one or two inches of new growth on the stems so new branches can develop from the most recent growth, not old growth. Aim for a rolling, wave-like appearance rather than a long, hard-edged block.

Plants that tolerate shearing best include: privet, holly, yew, euonymous, barberry and abelia. Those that do not and should be trimmed with hand pruners, loppers, saws, pole pruners and/or hands include: pines, spruce, fir, junipers, boxwood, arborvitae, forsythia, viburnum, rhododendron and lilac.
Formal and informal hedges can be kept vigorous for years by cutting out 10-30% of the canopy and one-third to one-quarter of the oldest branches near the ground each year, before new growth starts.

Keep your hedge clean at the base, particularly during rainy periods, when fungus may attack it. Avoid mulching it – the foliage shields the soil from the sun – and remove any leaves that blow underneath it.
In the meantime, happy gardening!
Editor’s Note: Laetitia Sands is a master gardener in Dorchester County.