26 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
sessiliflora grows faster than the other, it is still desirable to have 
a mixture of sessz/iflora in a plantation, for the reason that the 
bark of the thinnings is of more value, and would be almost the 
only return in the earlier years of the plantation. In preparing 
the land for planting, no better method can be adopted than to 
crop it with potatoes, which pulverises the soil better than the 
cultivation of any other crop. The oak plants, four or five years 
transplanted, should be put into pits at 4 feet apart each way, to 
be successful, and this operation will require to be carefully done. 
For the first three years the plantation should be hoed annually, 
after which tall weeds, brambles, etc., can be cut down as occasion 
requires. 
THINNING. 
The thinning may commence from the seventh to the tenth year, 
and here great judgment is required, as no hard and fast rule 
can be laid down. The only plan that can be recommended in 
the first thinning is to cut out the weakest plants, and if two or 
more robust plants are found side by side to leave them alone for 
another time. Before the second thinning, which may be taken 
in another seven or ten years, all the undergrowth should be cut 
clean out. The trees will now be, say, twenty years of age, and 
greater judgment, if possible, will be necessary at this thinning, 
as the proportions of the trees and their likelihood to become useful 
timber must be calculated with a skilful eye, and the fittest 
selected to remain. Some writers have recommended that a 
certain number per acre should be left, and that they should stand 
at equal distances apart. This is questionable advice, for in all 
probability there will be three classes of trees in the plantation, 
namely—first, those with a straight leader going ahead ; second, 
those with a short stem, and inclined to have a branchy head; 
and third, those which it would be difficult to class as a tree or 
shrub. These last should all be cut over, unless there are special 
reasons to the contrary, as the shoots from the stools will come in 
to be cut as underwood at the next thinning. The second class to 
have plenty of room to develop their head, as in consequence of 
their short stem they will be the first to come in as marketable 
timber. The first class may be left closer together ; two or more 
may be no farther than 8 feet apart, as many fine timber trees are 
found growing as close. In the third thinning proceed as in the 
second, and the cuttings of the underwood should now be of some 
