174 ON PLANTING AND MANAGING 



colder in consequence of the stimulating substances of 

 which they are composed, and the frequent top dres- 

 sings they receive, settling down into a solid adhesive 

 mass, and thereby increasing the disparity that exists 

 betwixt the temperature of the roots and branches. 



And it is this disparity that is the prolific source of 

 the mishaps and failures that are so constantly occur- 

 ring with vines under glass, especially with those that 

 are forced early. The colder the soil is in which the 

 roots are planted, the later will it be in spring before 

 they move and yield nourishment to the branches ; 

 and, unless some kind of artificial warmth be given to 

 the roots, they cannot produce new ones, until excited 

 thereto by the influence of the solar rays, and these are 

 not sufficiently powerful for that purpose until a long 

 time after the vernal equinox. The difference in point 

 of time which exists betwixt the period when the buds 

 open, and the shoots of the vine elongate, and that of 

 the emission of new roots, is at all times much greater 

 than is usually supposed. Even vines on the open 

 wall, the roots and branches of which are moved solely 

 by the natural warmth of the sun, generally produce 

 leading shoots three or four feet long before any new 

 roots make their appearance.* 



* This year (1844) the author had occasion to examine 

 upwards of a thousand young vines (part of his nursery stock) of 

 the respective ages of one, two, and three years, the shoots of 

 which had been growing, although slowly, from the 1st of April 

 until the 1st of July, on which latter day the examination took 

 place. 



But notwithstanding a period of three calendar months had in- 

 tervened, not one of these vines had the slightest appearance of 

 the formation of any new roots. The shoots and leaves had 

 therefore been living during that long period of time entirely on 

 the sap contained in the buds and the small portion of wood left 

 in, in the preceding year. 



The unexampled drynessof the spring was, without doubt, the 

 cause of the non-appearance of the new roots at so late a period 

 of the season. 



