TAMING THE WILD BLUEBERRY 109 



The peat most successfully used for potting blueberry plants is an 

 upland peat procured in kalmia, or laurel, thickets. In a sandy soil 

 in which the leaves of these bushes and of the oak trees with which 

 they usually grow have accumulated and rotted for many years, 

 untouched by fire, a mass of rich leaf peat is formed, interlaced by 

 the superficial rootlets of the oak and laurel into tough mats or turfs, 

 commonly 2 to 4 inches in thickness. These turfs, ripped from the 

 ground and rotted from two to six months in a moist but well- 

 aerated stack, make an ideal blueberry peat. A good substitute is 

 found in similar turfs formed in sandy oak woods having an under- 

 brush of ericaceous plants other than laurel. The turfs of low- 

 bush blueberries serve the same purpose admirably. Oak leaves 

 raked, stacked, and rotted for about 18 months without lime or 

 manure are also good. The leaves of some trees, such as maples, 

 rot so rapidly that within a year they may have passed from the 

 acid condition necessary for the formation of good peat to the 

 alkaline stage of decomposition, which is fatal to blueberry plants. 

 Even oak leaves rotted for several years become alkaline if they are 

 protected from the addition of new leaves bearing fresh charges of 

 acidity.^ The much decomposed peat in the submerged lower layers 

 of deep bogs, such as is used for fuel in Europe, is not suitable for 

 blueberry-soil mixtures. 



TUBERING. 



By ordinary methods, cuttings of the swamp blueberry have been 

 rooted only in occasional instances. Successful special methods, 

 however, have now been devised for these plants. Wild stocks of 

 the swamp blueberry vary greatly in their response to propagation 

 by a particular method, and it is likely to prove true that one 

 variety of cultivated blueberry can best be propagated by one of 

 the methods here described, others by another. The most novel 

 of the methods devised, but the one easiest of operation, is that of 

 tuljcring. This method involves the same principle as that em- 



' For a fuller discussion of the conditions under which leaves decompose into leaf peat 

 as distinguished from leaf mold, and the fundamentally dififerent effect of the two on the 

 growth of plants, consult "The Formation of Leaf mold," Smithsonian Report for 1913, 

 pp. 333 to 343 (also separately printed). 



