Wind can damage plants by drying them out, by breaking branches and tearing leaves, and by increasing the damaging effects of high or low temperatures. The wind can be even more damaging when combined with other environmental stresses, such as heavy rain or intense cold. Branches already heavily laden with water, snow, or ice break more easily in a high wind. Saturated soil doesn’t hold roots as tightly as unsaturated, allowing trees to blow over in high winds.
Windbreaks
Windbreaks quiet the wind for about 6 times the height of the windbreak. A 6-foot fence breaks the force of the wind for a distance of about 36 feet; a 25-foot windbreak for 150 feet.
The most effective windbreaks are permeable to allow some air to pass through. The force of the wind is like that of a wave of water hitting a barrier. If the barrier is solid, the wave tumbles turbulently over the top. If the barrier has openings, such as the space between pilings on a jetty, the force of the wave diffuses. Wind will travel over or through your windbreaks in the same manner. Partially-open fence, such as a lattice fence or one with the boards spaced a few inches apart, are more effective windbreaks than solid fences or walls.
Hedges are excellent windbreaks when mature, but they may need temporary structural assistance when young. Lath screens, perforated plastic sheeting, and burlap are all good materials to use for constructing temporary windbreaks.
If your homesite needs a large windbreak, choose deep-rooted trees. Some shallow-rooted species are fast growers, but they may blow over during heavy wind, especially during a storm when the ground is saturated. A local nursery should be able to help you select trees with a good combination of fast growth, deep roots, and sturdy branches that will not break off easily.
Unless the trees you select for a windbreak sweep the ground, wind can blow under the trees as they mature. Plant a row of shrubs in front of the trees to block this wind.
Desiccation
The most common garden injury caused by wind is the drying out of soil and roots. The evaporation of water from topsoil and leaf surfaces is greatly accelerated by wind action. Plants that were soaked the day before can dry out and wilt in several hours of heavy winds. Young or fleshy plants such as vegetables are particularly susceptible to dehydration by wind. Give your plants plenty of extra water during windy times.
The drying effect of wind is particularly severe during cold winters. When the ground is frozen or dry, evergreen plants can’t take up water to replace that dried out of their leaves by the wind.
Protecting Vegetables
Planting vegetables in alternating rows of tall and short plants can protect the smaller plants against wind damage. A windbreak of sunflowers, corn, or staked tomatoes can be planted along one or two sides of a vegetable garden to provide protection for the smaller plants.
Very young vegetables can be planted between tall mounded rows of soil, covered with bottomless paper bags, or protected by other small structural windbreaks
Preventing Wind Damage to Trees
Wind damages many trees that could have been protected by proper preparation. A young tree that has grown considerably during the summer may need to be thinned before heavy fall winds arrive. Removing several branches to create a more permeable top growth with reduced wind resistance may mean the difference between a snapped trunk and a sound tree. While you are training trees, prune them to develop strong crotches that can withstand wind. For instructions, see Pruning Young and Newly Planted Trees.
Gradual water saturation of the ground will weaken the root hold and make the tree subject to blowing over. Trees should be encouraged to form deep roots. If a tree is watered frequently and lightly, the roots will naturally tend to grow close to the surface. If the tree is watered less often but thoroughly soaked, the water will penetrate deep into the soil and the roots will be encouraged to grow deeper in search of the water.