456 EFFECTS OF SEVERE COLD ON PLANTS. 



of the roots. Many weeds were destroyed, such as usually survive the winter 

 as young plants, springing from seed late in the autumn. Paparer rhaas and 

 Fumaria officinalis are examples of this. The leaves of the Common Parsley 

 were killed; those of Common and Lemon-scented Thyme mostly escaped, 

 excepting where the snow thawed hy day and froze upon them at night. Cactus 

 opuntia, under a hand-glass, escaped serious injury. 



In a general way, these remarks will apply to a tract of country extending 

 along the banks of the Thames, from Kingston to Walton, constituting a level 

 plain of about six miles long, and varying from a quarter of a mile to two miles 

 in width, on the Surrey side of the Thames. This plain is probably not more 

 than twenty to fifty feet (according to situation) above the highest tides of the 

 Thames. To the south of it, the surface rises in undulations, gradually becoming 

 higher until we reach the Chalk hills some ten or twelve miles distant. In 

 whatever direction we quit this plain, and ascend the low hills which bound it, 

 the injury to vegetation is found much less. At a hundred feet of elevation, the 

 Laurels escaped with slight injury ; but the Bays and Laurestinuses were cut 

 down. In the sheltered gardens of Hampton Court, on the opposite side of the 

 Thames, the injury was almost as great as in my own garden ; although the 

 night frosts of spring affect the latter much more, as it lies on the side of a large 

 common (formerly a marsh), from which the radiation of heat is very rapid 

 during severe nights. 



The conditions which appeared to have been most favourable to plants, during 

 the cold, were exposure to the north, dryness of soil, recent transplantation, 

 layering of the branches, and absence of shade during the preceding summer. 

 Many gardeners believe that recently-transplanted shrubs suffer more from the 

 winter's cold ; and this may be the case where they are not rooted afresh, and 

 during windy weather. I am certain, however, that the most recently-planted 

 escaped the best ; and the advantage was not confined to those removed in the 

 autumn preceding, but could be distinctly traced in those which had stood two^ 

 three, or more years ; others of the same age suffering to a greater degree, where 

 longer fixed without transplanting. 



The preceding remarks apply to plants in the open ground, not protected in 

 any way, unless so mentioned. I may add further, that the frost penetrated a 

 cold-frame for half-hardy plants ; the soil in the pots being hard frozen for ten 

 days or upwards. They were thawed very slowly in the dark. Some were lost, 

 but several Cape Heaths, Oxalides, Pelargoniums, Mesembryanthemums, and 

 Fuchsias escaped with slight injury. Alee veviucosa, Petunia nyctaginiflcra. 

 Cyclamen conm, Eccrcmocarpus scaber, Saxifraga sarmentosa, Salvia splendens, 

 Calla jEtkinpica, Ixia crocata, Primula sinemis, Oranges, Myrtles, Scarlet Ver- 



