254 THE NURSERY-MANUAL 



Blandfordia. Liliaceoe. 



Multiplied by seeds sown in sandy peat with mild bottom heat ; 

 by offsets ; and by division of the old plants, which must be per- 

 formed when repotting in early spring. 



Blechnum. Polypodiacece. 



Propagated by spores and by division from the end of the rhi- 

 zome. See Ferns, page 312. 



Bletia and Bletilla. Orchidaceoe. 



These are terrestrial, and their flat roundish pseudobulbs are 

 usually under ground. They bear division well, especially Bletilla 

 hyacinthina, which may be cut up into pieces consisting of a single 

 pseudobulb. See Orchids, page 372. 



Blueberry (V actinium corymbosum, and other species), Ericaceae. 

 (Frederick V. Coville.) 



Propagated by removing and perhaps dividing bushes or clumps 

 from the wild ; by layers ; by cuttings ; by seeds ; by graftage. 



Seeds washed from fresh berries and sowed at once in two parts 

 of peat to one part of clean sand will begin to germinate in two to 

 four weeks if the night temperature is kept down to 60 F. 



Selected and hybrid blueberries do not "come true" from seed. 

 Lowbush blueberries which spread by rootstocks are readily prop- 

 agated by division, but highbush blueberries usually have no 

 rootstocks and cannot be propagated satisfactorily in this way. 

 Layering and mound-layering are easy but slow. Soft-wood 

 cuttings root with great difficulty because of the excessive heat 

 of summer. Various special methods of propagation have been 

 devised. The most useful of these are "stumping" (which, like 

 layering, is slow), "tubering," and winter cuttings. Budded 

 plants are unsuitable for permanent plantings because they are 

 continually sending up new and undesirable shoots from the 

 stock, but budding affords the quickest means of growing a large 

 amount of cutting-wood from a valuable young hybrid. Graft- 

 ing is more difficult and less satisfactory than budding. 



The sand used in cutting-beds should be clean, with reference 

 especially to clay, bacteria, lime, and salt; the peat either bog 

 or upland, but formed from ericaceous plants and taken from 

 near the surface ; and the water free from lime. 



Stumping. Cut the bush to the ground in the dormant season, 

 outdoors. Cover the stumps 2 to 3 inches with a mixture of 1 



