288 SCIENCE PROGRESS 



specialised experiments followed which served to account for 

 the results on the lines explained above. 



The Proper Depth for Planting 



Two questions of considerable importance remain to be 

 noticed in connexion with planting. These are the depth at 

 which a tree should be planted and the preparation of the soil 

 before planting. A safe practical rule is to plant the tree at the 

 depth at which it was growing in the nursery, this being easily 

 recognisable by the mark of the earth on the stem. In some 

 cases, however, purely for experimental purposes, we planted 

 trees with their roots buried to a much greater depth and were 

 surprised to find that these flourished much better than those 

 planted at the ordinary depth. These trees, however, were not 

 fruit-trees in the horticulturist's acceptation of the term but 

 young paradise stocks. The accompanying illustrations will 

 show what had happened and will serve to explain the apparently 

 anomalous results. In Figs. 6 and 7 are shown six of the stocks 

 as they were before planting and the same stocks as they 

 appeared when lifted two years afterwards. In this case they 

 had been planted with their roots 6 inches below the ground- 

 level, this being indicated by the horizontal line in the figures. 

 The root-system at the end of the two years is practically the 

 same as that in existence at planting but more developed. Fig. 7 

 represents six trees planted with their roots 24 inches below the 

 surface ; in this case the behaviour of the trees has been very 

 different : the original root-system has not developed and in 

 most instances has visibly shrunk, these roots and a portion of 

 the stem above them gradually dying; but in their place there 

 has arisen from the stems higher up a new root-system and the 

 new roots composing it, having found abundance of stored 

 material for their nourishment, have developed strongly and, as 

 a consequence, the growth of the branches, also, has been much 

 more vigorous than in the case of the trees planted at the 

 ordinary depth. Similar, though less marked, effects followed 

 when the trees were planted 12 inches below the surface. 



These experiments, by illustrating the vigour of new rootlets 

 arising from the thicker root-bearing portions of a tree, have an 

 important bearing on the explanation already given of the 

 results of careful and rough planting but they must not be inter- 

 preted as showing the advisability of planting an ordinary 



