Windbreaks
From Antivist
Windbreaks are not meant to be wind-stops. This can be responsible for other problems.
Windbreaks can cause their lee to be colder than would be the case without their protection. Because of this, damage may accompany spring or fall frosts. If so, the windbreak has become a windstop. This condition can be prevented by spacing the trees far enough apart to allow reduced air movement through them, by reducing the number of trees or shrubs already planted, or by pruning out some of the branches.
Windbreaks are not necessarily wasted space. If the trees are conspicuous when in flower or in autumn colors, especially when evergreens are included among them, they have an ornamental as well as a practical use that makes them doubly valuable. In other cases, if we plant Shadblow (or Juneberry) Mulberry, Hackberry, Highbush Cranberry, and other fruit and seed bearing trees and shrubs we may attract birds away from our cultivated berries and yet gain all the advantages of their aid in keeping down insects in our gardening and fruit growing.
Profitable trees for windbreaks are: English Walnuts, Almonds, Apricots, Fig, Filberts, Black Walnut, Northern Pecans, Highbush Cranberries, Elderberries, Raspberries, Blackberries, and Sugar Maple.
Windbreaks reduce evaporation of water from the soil and transpiration from the crop plants, particularly the leaves. Thus they mitigate the effects of drought, and winter injury which often follow a dry summer and a wet autumn.
The harmful effects of winter are lessened by the retention of leaves and snow on the ground, for in the lee of a windbreak, the ground freezes less deeply than where they are blown away, so the roots of the fruit trees, bushes and other plants are less likely to be injured because of their presence.
They also greatly enhance the physical comfort and noticably reduce the cost of maintenance of man and animals whose living quarters they shield from winter winds. Houses are protected, require less fuel to maintain comfortable temperatures than do adjacent similar ones not so favorably placed, and animals so sheltered need less food to keep them in condition favorable to the production of work, milk, eggs, and flesh.
Windbreaks should not be planted before careful study has been made of the local conditions, especially with respect to air, drainage - the flowing of cold air from higher to lower levels. This must be done to prevent cold spots or 'pockets'.
Planting should be not less than 50', preferably 100' away from the principal area or buildings to be protected. Its influence extends for a distance equal to 20 times its height; that is, trees 30' tall influence the force of wind for 600' on the level. On the protected of lee side of a windbreak of 10' to 30' is a calm zone where snow drifts during wind-driven storms. Hence the necessity of planting far back from buildings.
The length of the planting will depend on the area to be protected. It should extend at least 50' beyond the last building, or feed lot area. Where you have an L-shaped lot, greater protection may be had by extending the planting 100' to 125' northerly or westerly beyond the buildings.
Conifers are the most suitable for windbreaks. Hardwood trees are the least recommended. Conifers should be at least 3 years old, 4 year or 5 year for white spruce, Douglas or Balsam Fir, White Pine, Norway Spruce, Chinese Elm, and Red Maple go in light loams, White Spruce, Balsam Fir, Arborvitae, Cottonwood, Ash and Sugar Maples for heavy loams and clays.
Two or more species of trees in a windbreak provide a more compact growth of foliage than when only one is used, especially where spruce and arborvitae are used with open growing White or Norway Pines. The possible loss of one species from a future insect or disease epidemic will thus not destroy the windbreak. Russian Willow or Cottonwod may be used to give early protection while the slower conifers are becoming established in their lee.
Where there is enough space, three rows are desirable, otherwise two. For all suitable trees except Arborvitae, the rows should be 8' apart and the trees 6' asunder. Arborvitae should be 6' to 8' and the trees 4' asunder. On sandy soils where growth will generally be slow, the trees should be staggered in rows, on fertile ones they should be planted in checks because in 12 to 15 years, they will crowd at 6' to 8'. Then by removing each alternate tree in each alternate row, the remaining trees will be left in staggered positions at wider spacing. Where arborvitae is planted, the original spacing should be maintained. thinning will not be necessary.
Windbreaks depend for their usefulness largely on the care the receive for the first five or six years after planting. Keep poultry and livestock out by fencing them. A mulch of straw, marsh or salt hay or sawdust 2" deep and 12" in a radius around each tree should be applied within a few weeks of planting. This will hold soil moisture and help to smother weeds. Sod growth around the trees must be prevented.
To avoid heaving by frost, a winter mulch 4" to 6" deep of straw with a low percentage of manure should be applied after the ground is frozen and preferably after a light snow is on the ground there will be no danger of mice nesting in it. It should remain on the ground the following summer to add fertility to the soil, prevent evaporation of moisture and smother weeds.
You may grow sunflowers in several rows along the windbreak the first few years to protect young seedlings and the sunflowers can be used to feed chickens or use for silage. (People like to eat these too) Conifers in a windbreak should never be pruned. It is desirable to retain those branches that grow near the ground. If trees have enough sunlight, they will maintain their foliage throughout most of their lives.
