RESTING VEGETATION. 367 



dryness, and this is readily imitated in hothouses, in consequence of 

 the plants being in pots. There are some tropical plants, however, which 

 though in certain localities they have what almost amounts to a short 

 cessation of growth, yet in a state of culture will succeed better without it. 



The natural period of rest in hardy plants may be varied or changed 

 by withholding moisture, even without reference to temperature. We 

 see this taking place both with trees and herbs in dry seasons : when 

 wood is ripened, leaves drop off; and grass fields become brown in 

 July and August, which in moist seasons would have continued grow- 

 ing till October or November. By imitating these effects in gardens, 

 the operation of accelerating and retarding may be greatly facilitated ; 

 and the imitation is easy when plants are kept in pots. Even pruning 

 after the leaves drop in autumn, as we have seen, has a tendency to 

 produce an earlier development of the buds than when that operation 

 is deferred till spring ; because the number of buds to be nourished 

 during winter being smaller, they are swelled to a larger size, and are 

 more ready to be developed. In general, whatever tends to ripen the 

 wood in ligneous plants, and mature the leaves in herbs, tends to bring 

 the plant into a state of repose ; and hence the value of walls, dry 

 borders, dry soils, and warm exposures. 



The advantages of putting trees that are to be forced into a state of 

 rest, and thus rendering them as excitable as possible previously to 

 the application of artificial heat, are now well understood by gardeners. 

 The period of maturity, under any given degrees of temperature and 

 exposure to the influence of light in the forcing-house, will be regulated 

 to a much greater extent than is generally imagined by the previous 

 management and consequent state of the tree, when it is first subjected 

 to the operation of artificial heat. Every gardener knows that when 

 the previous season has been cold and cloudy and wet, the wood of 

 his fruit trees remains immature, and weak abortive blossoms only are 

 produced. In the autumn, the plants have just sunk into their winter 

 sleep ; in February they are refreshed and ready to awake again : and 

 wherever it is intended prematurely to excite their powers of life into 

 action, the expediency of putting these powers into a state of rest early 

 in the preceding autumn appears obvious. Mr. Knight placed some 

 vines in pots in a forcing-house, in the end of January, which ripened 

 their fruit in the middle of July ; soon after which the pots were put 

 under the shade of a north wall in the open air. Being pruned and re- 

 moved in September to a south wall, they soon vegetated with much 

 vigour, till the frost destroyed their shoots. Others, which were not 

 removed from the north wall till the following spring, when they were 

 pruned and placed against a south wall, ripened their fruit well in the 

 following season in a climate not nearly warm enough to have ripened 

 at all, if the plants had previously grown in the open air. Peach-trees 

 somewhat similarly treated unfolded their blossoms nine days earlier, 

 " and their fruit ripened three weeks earlier than in other trees of the 

 same varieties." Pots of grapes which had produced a crop previously 

 to midsummer were placed under a north wall till autumn ; on the 12th 

 of January they were put into a stove, and ripened their fruit by the 



