Trees and shrubs can help you protect your home from freezing winds, or to shade your roofs, windows and walls, and to channel breezes into your rooms. Use them for home comfort and low energy bills.
But choose well. Plants vary in their shape and mature sizes, as well as in their growth rates, foliage density and watering needs.
Evergreens vs. Deciduous trees and shrubs
Use evergreen trees and shrubs to protect your home from the wind, and deciduous (in cold climate and moderate climates) or evergreens (hot climates) to shade your house.
Deciduous plants will provide shading during the summer, while allowing sunshine to warm your home in the winter.
The shape of the trees is a major consideration; it varies a lot, and you should consider it according to your needs and goals. Here, we are going to consider 6 types of shapes, for landscaping goals: round-top, spreading, fastigiate, pyramidal, columnar and open headed trees.
(ex: white oak; sycamore, at left…):
round-top trees are excellent for shading; a single tree can provide shade to very large surfaces.
(ex: sugar maple, at right):
they are good for shading walls and roofs; they tend to grow wider than their height.
(Fastigiate Washington hawthorn, at left; Lombardy poplar):
narrow trees, usually planted in a row; they are excellent as windbreaks or to place closer to homes, when space is scarce.
(Douglas fir, at right; Magnolia, Acacia): pyramidal trees are good for tall windbreaks and hedges.
(Sentry maple, at left; Columnar red maple…):
they are very narrow trees, good to shade walls and roofs from afar.
Open Headed trees
(Honey locust, at right; silk tree…):
their indistinct shape and low density foliage make them excellent lawn trees; they are a good choice in colder climates, to get filtered sunlight; they are a poor option for windbreaks or even for shade.
Trees and shrubs should be located at a proper distance from the house and from each other.
When using trees and shrubs in windbreaks, consider planting them at a distance of 2-6 times the mature height size of the plants; to shade the house, plant large trees at 20 feet (6 meters) or more from it.
The distances should be calculated by taking into consideration the mature crown size of the plants - even if at the beginning they look very far apart and distant from each other or the house.
When buying, inform yourself about the mature size of the trees and shrubs you are interested in.
Density of foliage
As mentioned earlier, the foliage of the plants can be open, and provide a gentle filtration of the sun; but plants with this type of foliage are a very poor choice for shade, and are not adequate for windbreaks.
Plants in windbreaks should have a high foliage density; a tree will reduce wind speeds and sunlight (30-60%) according to the density of its foliage…
Rates of growth
Though fast-growing trees and shrubs are the best choice for the most immediate needs, low-growth plants are a better choice in the long run.
Typically, low-growth plants have a higher lifespan, a deeper rooting depth, and are more disease-resistant and less prone to branch breakage during snowfalls or high-wind periods.
The maintenance and the watering needs of each plant are also important considerations, and you should keep it in mind, when buying...
Water shortages or special pruning needs, will make it even more important.
Vines are usually grouped in three main species: clinging vines, twining vines and tendril vines. Clinging vines stick easily to solid objects, and develop aerial roots, which can damage the walls, particularly brick walls. These vines comprise species as the trumpet creeper, the winter-creeper or the climbing hydrangea. Climging vines may damage the house structures or its walls. Pay attention to it. Twining vines as the kiwi, the bougainvillea, the morning glory, the american bittersweet, the honeysuckle, or the american wisteria are fast-growing species that need something to twist around and to support them as they grow. Vines with tendrils - grape, passionflower… - need strings, wires, or other supports to grasp onto.
Native vs. Imported Plants
Are the plants that you are considering to buy native to your region and microclimate? That’s another type of question that you should ask to yourself and to the plant nursery staff.
Contrary to imported plants, native plants have been tested by Mother-Nature in your climate and type of soils, over thousands of years.
It's always very difficult to say if imported plants are a good answer to local soils and climates; only their record of success or failure in each region can prove it. Many imported plants are a bad idea, and a waste of money and time.
Where to buy
Local plant nurseries are the best place for advice and to buy. Plants sold by big retail stores may come from distant nurseries and different climates.
Exotic, non-native and unknown plants are the shortest path to failure. When planning shade or windbreaks, make sure that the species of plants you are considering are adapted to your climate and soil.
Shop locally and ask the advice of landscapers or experienced plant nursery professionals.