162 



Canadian Forestry Journal, April, J9J9 



WINDBREAKS FOR ORCHARDS 



By IV. T. Macoun, Dominion Horticulturist. 



The object of a windbreak is, as the word in- 

 dicates, to break the force of the wind; and the 

 object of breaking the force of the wind is to 

 protect the trees from the injurious effects of ex- 

 posure to the full force of it. The protection of 

 the windbreak prevents the trees from becoming 

 loosened or blown about by it, and thus having 

 their growth checked. A windbreak also pre- 

 vents trees from becoming unshapely as they 

 often do when exposed to the wind. It protects 

 the trees from cold winds which would check 

 the development of the trees during the growing 

 season. Windbreaks prevent fruit from being 

 blown off the trees, and in the prairie provinces 

 in particular they help to prevent winter killing, 

 and the drying out of the soil by hot dry winds 

 in summer. 



At the Experimental Station at Charlottetown, 

 P.E.I. , Nappan, N.S., St. Anne de la Pocatiere, 

 P.Q., and Cap Rouge, P.Q., it has been found 

 necessary to plant windbreaks to protect the 

 orchards which at all of these places are situated 

 where they have little natural protection, and 

 where frequently the winds are high and cold. 



On the Prairies. 



Windbreaks are necessary on the prairies to 

 lessen the drying effects of the wind both in 

 winter and summer. It has been found that 

 trees suffer less from winter there, where they 

 are protected by a windbreak. 



In the Provinces of Ontario and British Col- 

 umbia, and in parts of the Maritime Provinces, 

 where fruits are grown in valleys and on slopes 

 where there is good naturar protection, or where 

 they are grown where high winds are not pre- 

 valent, windbreaks are not so necessary; and 

 in fact inmany cases it may be better to have 

 no windbreak, as the windbreak lessens the cir- 

 culation of air, and injurious insects are liable 

 to multiply much more rapidly. 



A good circulation of air is necessary, also, in 

 combatting fungous diseases, as it is important 

 to have leaves and fruit dry off as soon as pos- 

 sible after dew or rain; hence anything like a 

 windbreak, or unpruned trees, which lessens 

 circulation, may do more harm then good. 



Value of Spruces. 



In Eastern Canada the white and red spruces 

 make good trees for windbreaks, though the Nor- 

 way spruce will in most places grow somewhat 



faster, and is a good tree for this purpose. A 

 single row of these, planted from eight to ten 

 feet apart is quite sufficient under most con- 

 ditions. The windbreak should be at least fifty 

 feet away from the first row of fruit trees in 

 Eastern Canada. The Norway spruce will grow, 

 if properly cared for, at the rate of from two to 

 three feet a year until it reaches a height of 

 fifty or sixty feet or more. In very exposed 

 places it is desirable to plant two rows of trees, 

 the trees forming the second row being planted 

 from eight to ten feet behind the trees in the 

 first row. The first row may be composed of 

 American Arbor-Vitae, which is rather slow 

 growing, and the row behind made of Norway 

 spruce or native spruce, if desired. White pine 

 and European larch are also rapid growing trees 

 which are useful for windbreaks in Eastern 

 Canada. Scotch pine is inclined to be ir- 

 regular in growth, and is on this account some- 

 times not satisfactory. Other trees, both native 

 and exotic, will also give good satisfaction. Lom- 

 bardy poular planted about eight feet apart 

 makes a windbreak in a short time, as it is a 

 very fast growing tree. 



Fruit Protection. 



While windbreaks are useful in Eastern Can- 

 ada, they are absolutely necessary on the prairies 

 where there is no natural protection. A wind- 

 break on the south and west sides of an orchard 

 or small fruit plantation to check the hot winds 

 is of as much or greater importance on the 

 prairie than one on the north and east sides 

 to check the cold winds, hence it is desirable to 

 enclose a plantation with a windbreak. Fruit 

 trees growing close to the south or west sides of 

 windbreaks may be more injured than benefited 

 by the windbreak, as in late winter or early 

 spring the sun shining on the south or west sode 

 of a windbreak raises the temperature about the 

 fruit trees much higher than if the windbreak 

 were not there. The fruit trees thaw out every 

 day, frosts are severe night after night, and 

 these extremes cause severe injury or death to 

 the trees. Whereas, when fruit trees are on the 

 north or east side of a windbreak, this kind of 

 injury is not so likely to occur, and they get the 

 protection of the other windbreak from the cold 

 winter winds. 



