Designing For Early Warmth

Landscaping

One method of deflectinq the wind involves landscaping a windbreak on the windward side of the garden.
First shift some soil to build an earthwork (see ***); then plant trees on its leeward side. Select trees with varying heights at maturity—short at the top of the earthwork, tall at the bottom—so that the top of the windbreak is flat (see ***).

Profile planting

An A-shaped windbreak created from trees of varying height (see ***) has two aerodynamic advantages: the slope on the windward side protects the windbreak from damage, and the slope on the leeward side keeps turbulence to a minimum.

Windbreak dimensions

The length of a windbreak such as a hedge should be at least 11 times its mature height. This is because the wind will sneak around the ends and generate eddies. As a rule, a windbreak will give protection some 10 to 15 times its height.

A tree windbreak needs to be long enough and high enough to achieve its purpose (see ***). It is usually several rows deep, with a roughly triangular cross-section. Ideally, you should choose trees that have other purposes, such as providing edible fruit or altering the level of the water table, but usually there will have to be some compromise between these and the effectiveness as a windbreak and the speed of establishment.

A serious conflict may arise between the need for a windbreak and the need for light when the sun is low. This can occur in high latitudes; it depends on the direction of the prevailing winds. In climates where you need protection against hot, drying winds the shading from trees is a bonus.

Wind

A row of trees act as the first line of defence against the wind. These protect a row of shrubs, which provide a semi-porous wind barrier for the garden beyond.
Many tree species grow more vigorously when coppiced or pollarded. Harvesting provides material for fuel, fencing, basketry, or general garden purposes.