230 OUR FORESTS AND WOODLANDS 



any unnecessary branches below 2j inches in dia- 

 meter, and tarring the wound-surfaces, would be 

 well spent in the improvement of the bole. 



Where grown in pure plantations, larch woods 

 soon thin themselves and require underplanting. 

 A pure larch wood of about thirty to forty years 

 of age has only about half the density of a good 

 crop of Scots pine, and even the latter cannot 

 protect the soil for itself. Between the twentieth 

 and thirtieth year the necessity for a free grow- 

 ing-space makes itself unmistakably noticeable 

 in larch plantations ; and after that underplanting 

 is essential, unless the soil is to be allowed to 

 deteriorate and suffer gradual loss in capital value. 

 There is of course always a great inducement 

 to plant pure plantations of larch, as they soon 

 yield thinnings of marketable value even in spite 

 of the canker. And when the demand for such 

 small poles is good, as in hop-growing districts, 

 pure crops can prove highly remunerative. The 

 following example, furnished by an estate-agent on 

 the Chiltern Hills, may show how profitable larch 

 can be, even when grown on poor land, in southern 

 England. * Larch plantations on the chalk sub- 

 soil, overlaid with a good cap of flinty clay, 



