10 



THE GARDENER'S ASSISTANT. 



is true, afford a certain amount of shelter to 

 the interior of a garden, and by absorbing heat 

 from the sun, and radiating it again, a warmer 

 atmosphere is generated within the garden and 

 near the walls. It often happens in unsheltered 

 gardens, especially in changeable spring weather, 

 that, after the sun has heated the air in the 

 interior during a clear and comparatively calm 

 period of the day, and the motion of the sap 

 has been stimulated in consequence, the sky 

 becomes overcast and strong gusts of cold wind 

 begin to blow and sweep through the garden, 

 and quickly displace, by their mechanical force, 

 the warmer and lighter air. 



. Walls afford good shelter when there is little 

 wind, and that steady; but when there is much, 

 it eddies round the inside of the walls, and pro- 

 duces far more injurious effects on the vegeta- 

 tion it meets on its course than it does on that 

 which is entirely in the open ground, and not 

 subjected to intermittent excitement. It is 

 therefore of great importance that the progress 

 which vegetation makes in a garden should be 

 as much protected as possible from sudden 

 checks; and this protection mainly consists in 

 moderating the impact of cold winds. 



Plantations should therefore be made, if pos- 

 sible, on the north-west, north, and north-east 

 sides ; the winds from these quarters being 

 coldest. The shelter on the north and north- 

 east of the garden should approach nearest to 

 it, for these are the winds most to be dreaded. 

 The nearer the shelter, the more it will shade 

 the garden, and the less light will the plants 

 receive. But what can be grown on north and 

 north-east aspects is of little importance com- 

 pared with the subjects on the other and better 

 aspects ; so that the shelter of the latter is more 

 to be considered than the partial loss of light to 

 the former. Along the north side, the screen 

 may be as near as 60 feet, depending partly on 

 the kind of trees employed; and at about the 

 same distance off the screen may turn the north- 

 east and north-west corners, but should then 

 gradually open out to the south-east and south- 

 west, with a free exposure to the south. After 

 turning the north-west and north-east angles, 

 the latter of which should be specially guarded, 

 the shelter, instead of being a continuous belt, 

 may consist of clumps at intervals, having a 

 general direction to the south-east and to the 

 south-west, with other clumps farther off, and 

 opposite the intervals. 



A plan of a kitchen -garden indicating the 

 disposition of the shelter-belt of trees is shown 

 in fig. 794. 



The trees employed for shelter should be tall 

 and quick-growing species. In these respects 

 perhaps none excels the black Italian Poplar 

 (Populus monilifera). It will form a good shelter 

 in a few years, especially if the ground is well 

 trenched and manured previous to planting, 

 and afterwards kept clean, when it will increase 

 about 4 feet annually till it reaches a height of 

 60 feet or more. The Larch and Sycamore are 

 also quick-growing trees, and the same may be 

 said of the Lime (Tilia europcea). The latter 

 may be pruned and trained so as to form a 

 close screen, or tall hedge, from the ground 

 upwards. The Elm and Beech ultimately be- 

 come lofty, but their growth is slower. Where 

 the soil is suitable, the Norway Spruce (Picea 

 excelsa), the Scots Fir (Pinus sylvestris), the 

 black Austrian Pine (Pinus austriaca), and the 



| Corsican Pine (Pinus Laricio), answer the pur- 

 pose well, and form excellent shelter-belts. In 

 maritime districts, and especially in the milder 

 parts of Britain, Pinus insignis and Cupressus 



■ macrocarpa grow fast, and make first-rate shelter; 

 and the hardier Thuia gigantea and Cupressus 

 Lawsoniana are very useful and effectual shelter- 

 giving trees. 



The belt should be not less than 20 yards 

 wide, and should be planted so that the quickest 



i growing trees are on the inner half, and the 

 sturdier and more branching species on the 

 outer edge, where they are most exposed to 

 the wind. The Poplar, for instance, mixed 

 with Spruce, or the giant Arborvitae, should be 

 planted next the garden, and some slower-grow- 

 ing trees, such as Elm, Beech, Sycamore, Scots 

 Fir, Austrian Pine, or Lawson's Cypress, accord- 

 ing to the nature of the soil, will form the 

 outer half of the belt. By its rapid growth the 

 Poplar quickly forms a shelter, and if its appear- 



I ance is not liked, the trees may be cut down 

 when the other kinds are high enough to afford 

 protection. 



If some outposts in the form of kidney- 

 shaped clumps of trees were established, the 

 force of the wind would be considerably broken 

 before it reached the belt. The clumps would 

 be most effective if arranged with their convex 

 side outwards in two series, and they may be at 

 the distance of 200 or 300 yards. The clear dis- 

 tance between the clumps in each series should 

 be about equal to their length, and the intervals 

 so formed should be covered by the clumps in 

 the second rank or series. In passing through 

 between the outer clumps the velocity of one 

 portion of the wind will tend to neutralize 

 the force of the air sweeping round the end 



