96 The AmatSur's Booh of the Dahlia 



Soot from the chimneys where wood or soft 

 coal has been burned, added at the time the 

 sheep manure is put in — about a handful of this, 

 not more, to each plant — will give brilliancy of 

 colour to the pink, red, or yellow ones. Do not 

 give any to lavender dahlias, for they will turn 

 magenta; or to the white ones, for they will not 

 remain pure white. If you live in a steam-heated 

 house and have no open fireplaces, you must in- 

 vest in Scotch Soot, which may be bought at a 

 seedsman's shop. 



Chemical fertilizers are not to be recommended 

 for dahlias. The ingredients are all too con- 

 centrated to come in contact with the roots, 

 and if scattered on the surface to be washed in 

 by rain, the action is too uncertain to give satis- 

 faction. Nitrate of soda is often given in place 

 of the sheep-manure tonic, but in my own ex- 

 perience the results have not been so satisfactory. 

 There is no doubt that it weakens the vitality of 

 the tubers, and the next year's growth is poor and 

 weak. 



Fertilizers mixed with the soil serve two 

 purposes. They either add plant food which is 

 immediately assimilated by the roots; or they 

 cause a change in the chemical composition, set- 

 ting free and making available plant food which 

 is already in the soil. 



