226 



CAUSE OF GUM IN STONE-FRUIT TREES. 



to the sllglitest pressure. Afterwards, these 

 were j)hiced in a cool pit. They received no 

 water for sis weeks. The soil was then ram- 

 med do\vn as tightly as it could be made, and 

 afterwards well watered. No I'oses ever made 

 a more handsome growth than these did in 

 this finely pressed and pounded soil. 



M}* practice has been much modified by 

 these and similar observations, though I have 

 no satisfactory explanation of the reason why ; 

 but theory must hang on skirts of practice 

 sometimes. I await further observation. 



I may remark, ere I conclude, that agricul- 

 turists are, for once, ahead of us. Since the 

 appearance of Stephens' " Book of the Farm," 

 they know the preference to be given to firm 

 soil, over that which is loose and porous. 

 To those who may not have this valuable 



work, the sentence to which I allude may be 

 interesting. Under the head of wheat, he 

 says,—-" The land receives only one furrow 

 after potatoes ; and it should have time to 

 subside a little before it is sowed, though the 

 usual practice is to sow the wheat upon it as 

 ploughed. The reason why I have so fre- 

 quently recommended the subsidence of the 

 land before sowing the seed, is, that wheat 

 thrives much better in soil having a little 

 firmness in it, than in the loose state the 

 plough leaves it."- — (Stephens' Book of the 

 Farm, vol. ii, page 417, — cheap American 

 edition by the editor of the Plough, the Loom, 

 and the Anvil, Philadelphia.) [Highly in- 

 teresting facts. Ed.] 



Thomas Meehan. 



Bartram Botanic Garden, Philadelphia^ Oct., 1850. 



ON THE CAUSE OF GUM IN STONE-FRUIT TREES. 



BY A SUBSCRIBER, BOSTON. 



Gumming in Peach, and other stone-fruit 

 bearing trees, has been the subject of various 

 conjectures and experiments among horticul- 

 turists, but, as far as I can learn, very little 

 has yet been made of it, and little light has 

 been thrown on the subject in regard to the 

 real cause of the malady, or. a method of cu- 

 ring it. Most gardeners and horticulturists 

 agree in calling it a disease — a very injurious 

 one to the tree ; and from its general charac- 

 ter, we are very naturally led to draw this 

 conclusion. From various investigations, how- 

 ever, which I have lately made on this subject, 

 I am induced to form opinions regarding it 

 somewhat different from those which I have 

 seen recorded by others. 



In Britain the exudation of gum is attribu- 

 ted to the coldness of the seasons, and the wet, 

 unsuitable nature of the soil, and though trees 

 grow under glass, are not exempted from it — 



yet it is found that they gum less frequently 

 than trees on the walls, out of doors, where 

 alone they are cultivated in that country ; 

 nevertheless, we know very well, that trees 

 are often as badly gummed in peach houses, 

 under circulnstances apparently adverse to the 

 above causes, as they are out of doors, both 

 in this country and in England. Although I 

 would not assert that a cold climate and a wet 

 soil has nothing to do with it, yet my obser- 

 vations go far to satisfy me that there must be 

 a predisposing cause, before the trees can either 

 be affected by the cold or moisture. 



I have lately examined a large quantity of 

 peach trees, in the neighborhood of Baltimore, 

 some on dry, gravelly ground, and others un- 

 der glass, under conditions altogether preclud- 

 ing the possibility of the foregoing causes. In 

 both cases the trees were much gummed, and 

 always at the surface of the ground, or a few 



