A row of firs helps keep home warm

In the old days, back when many of our communities were settled, back when Maine was a frontier land consisting of hundreds of miles of uninterrupted forest, men and women came to our region and braved nature’s elements with relatively few buffers. If you’ve ever lived in an old home, you may have imagined the difficulty of winter with nothing but a few layers of board, horsehair plaster, a chilly fireplace and several layers of bulky woolen clothing between early settlers and the howling winter wind.

Yet, in northern New England, traditional architecture provides clues to how well the earliest settlers took on the elements with what we now would consider limited and low-tech building materials. With an eye trained on the brutal climate, colonists constructed homes for energy efficiency. Saltbox-style and Cape Cod-style homes were oriented south-southeast to maximize passive solar heat gain within the home during winter. The steeply pitched roof allowed for rapid snow-load removal, which served to naturally insulate the foundation area of the home. Long rooflines sheltered the living area from blustery winter winds.

Today, our part of the country is known for its relatively cool summers and roaring winter snowstorms. In much of our region, the harshness of winter extends from October to April, which amounts to a full half-year of difficult weather. Like birds flying south for survival, a portion of our residents migrate south for the winter in an effort to ease the discomfort of wintering here.

Gardeners who choose to stay in the most northern reaches of Maine throughout winter can relieve the experience with some careful landscaping. Insulating the home from the winter elements actually starts well beyond the physical walls of the home.

It may seem odd, during the first official week of spring, to be thinking about landscaping for winter, but really, nothing could be more natural. Fresh in your mind are your experiences this winter, your mental notes about observations made about the weather.

With this hindsight fresh in mind, think about what spring and summer plantings may be helpful in reducing the harsh affects of winter on your home.

You may not be able to tame the weather, but did you know that with energy-efficient landscaping you may significantly reduce the cost of heating?

First, it’s important to acknowledge that where winter heating is concerned, the wind is the enemy. Winter winds increase heat loss from the home and may be enhanced by landforms around the site. Hills, valleys, lakes, rivers, open fields, far-off tree lines – all may affect the flow and force of wind against the home.

When wind strikes the surface of the home, the velocity or speed of the wind is transformed into pressure. About half of that pressure flows downward, dropping to the base of the structure. The other half searches for an escape route. Even the smallest crevices – such as narrow, striplike openings around window and door frames – allow places for that pressure to dissipate. Naturally, this dissipation results in the transfer of air – the exchange and intermingling of cold air with warm air – from inside your home.

Even more significant, however, is the force of wind that skirts around and over the home. This force uses convection currents to essentially “pull” warm air out of the structure.

While a range of building materials provide significant buffer between the winter elements and the home, a windbreak of trees outside the home can protect the interior from heat-stealing winds. A windbreak can be crafted with trees, shrubbery and fencing. Plantings can be placed to deflect cold winds. Therefore, one must carefully analyze the direction of prevailing winter winds. In general, the harshest seasonal winds originate from the north, northeast and northwest. However, landforms may alter prevailing wind patterns.

This last piece of information is the crux of energy-efficient landscaping. The idea is to alter the wind patterns by manipulating the landscape across which the wind flows. Windbreaks planted (or constructed in the case of fencing) perpendicular to the prevailing wind force the flow of air up over buildings, thereby significantly reducing the loss of heat through convection forces.

An effective planting or fence line provides a barrier to energy loss within the area downwind of the windbreak. Some measure of protection from the wind begins in the space immediately downwind from the windbreak and extends outward to the area five to 15 times the height of the windbreak, depending on the plants or materials used in the windbreak.

Fences or solid structures offer the greatest resistance to wind, and therefore provide the greatest level of protection immediately downwind, but it may be difficult to attain any significant height with nonliving solid materials. Solid structures also may be undesirable in terms of aesthetics.

A natural windbreak of trees or shrubs may be more visually appealing. When plants are used as a windbreak, the entire row planting must be wider than the mature height of the plants. This more porous, relatively loose barrier offers a lesser level of protection from wind compared to solid structures, but the increased height of the windbreak creates a greater level of protection farther away from the base of the planting.

Planting evergreens such as pines, spruces and firs some distance to the north of the home may significantly reduce the loss of heat from the home during the winter months. For more information about energy-efficient landscaping, consult this authoritative reference: “Energy Efficient and Environmental Landscaping” by Anne Moffat and Marc Schiler.

Diana George Chapin is the NEWS garden columnist. Send horticulture questions to Gardening Questions, 512 North Ridge Road, Montville 04941 or e-mail dianagc@midcoast.com. Selected questions will be answered in future columns. Include name, address and telephone number.