THE TEEATMENT OF EOOTS 91 



stem and branches, owing to their more delicate tissues, 

 and to the larger percentage of water of the former. The 

 branches may, indeed, be made more resistant by certain in- 

 juries to the roots. Several cases are known in which the 

 branches of fruit-trees which were transplanted in the autumn 

 were less damaged by frost than those of trees which had 

 remained in their original positions. Such a phenomenon is, 

 in all probability, due to the fact that the branches contained 

 less water, as the transplanting, by damaging the many root- 

 tips, would interrupt the absorption of water, and consequently 

 stop the growth of the branches, and accelerate the ripening 

 of their wood. Under normal conditions the shoots of apple- 

 trees in a heavy soil will go on growing until stopped by the 

 frost. 



The greater liability to damage by frost in the roots of trees 

 transplanted in the autumn is not due to any greater sensitive- 

 ness of the root, but to the greater porosity of the soil, which 

 enables the frost to strike to a greater depth. The earth 

 around a newly-planted tree is much more porous than the 

 natural soil, which contains more water and allows the air to 

 circulate less freely ; and this is just what protects the roots 

 from frost. Hence, in transplanting in autumn, it will be found 

 advisable to heap up the earth one or two feet above the soil 

 around the tree, and open up the heap in the spring. 



It is the porosity of the soil, which only settles down after 

 many months, which causes trees transplanted in the spring 

 to suffer from dryness. It is therefore always essential to 

 wash the soil well into the root system. We should not be 

 stopped from doing this by the fact that the soil is already 

 very wet, or that heavy and continuous rain is falling at the 

 period of transplanting. It is of prime importance that a 

 layer of fine earth should cover in the rootlets as soon as pos- 

 sible, and this can only be done by washing it in. 



The practice of placing the roots in water previous to plant- 

 ing cannot always be recommended. The tissues absorb an 

 enormous quantity of water, and have afterwards to return to 

 a soil with a very much smaller supply. Experience, too, 

 teaches us that plants with great turgidity suffer most when a 

 dearth of water arises. 



