312 THINNING. 



tree, the kind of plantation, the soil and situation, and the climate. In 

 the case of a plantation where the object is to produce straight timber, 

 the first point to determine is the probable height to which the kind 

 of tree to be planted will attain in the given locality ; and then to 

 obtain from the experience of others, or from observation of natural 

 woods in similar localities, the distance required to enable a tree to 

 attain that height. A tree in a sheltered valley and on deep rich soil 

 not much above the level of the sea will attain double or triple the 

 height which it will on a hill at a distance from the sea ; the tempera- 

 ture in the latter situation being much lower, the soil generally poorer, 

 and the wind stronger. The subject of timber plantations not forming 

 a prominent feature in this volume, we shall only add that experienced 

 planters have laid down certain rules for thinning timber plantations, 

 and that the best of these we consider to be those of Mr. Cree, pub- 

 lished in the ' Gardener's Magazine' for 1841, and applicable to every 

 situation from the level of the sea to an altitude of 1800 feet. Sup- 

 posing the height which the trees in a plantation of round-headed 

 kinds are supposed to attain is 85 feet, and that they have been 

 planted at the distance of about 4 feet, tree from tree; then the 

 first thinning should commence when the trees are 13 feet 6 inches 

 high, and the trees thinned so that those that remain may stand at 

 twice the former distance from each other, or 8 feet apart each way. 

 The second thinning should take place when they are about 24 or 

 25 feet high, when the trees should be left so as to be 16 feet apart each 

 way, thus leaving 170 to the acre. The third thinning should take 

 place when the trees are about 47 or 48 feet high, when only 42 

 trees should be left to the acre to attain the height of 85 feet ; and 

 these must accordingly stand at the distance of 32 feet apart each way. 

 It is not pretended that these rules should in all cases be exactly 

 followed ; on the contrary, they are only given as approximations, the 

 result of extensive experience and scientific reasoning, for round- 

 headed trees; for poplars and coniferous trees, the final distance is 

 much less. (See Mr. Cree's table in the * Gardener's Magazine' for 1841, 

 p. 553, and also some excellent observations on the subject in the 

 ' Gardener's Chronicle' for 1842, p. 19, and in various other parts of 

 that journal and in the * Gardener's Magazine.') A forester should be 

 well impressed with the importance of light, air, moisture, and shelter 

 as regards vegetation; and he should closely observe the density 

 which the various trees that are under his charge will bear. In all 

 extensive plantations some trees will be seen suffering from being too 

 close : he should learn from cases of the kind how to proceed to thin 

 others that he can easily foresee are approaching a similar condition. 

 As a guide to the time when to commence thinning, we should say 

 Always when the trees are about to touch, but not yet touching. 



Thinning Ornamental Plantations. As the object of these is to dis- 

 play the natural character of the trees, either of their heads at a 

 distance, as in masses of groves or trees only, or singly, or in groups of 

 trees among under growths, or on smooth turf, it is obvious that 

 thinning is of as much importance to the desired result as in timber 



