THE ACCLIMATATION OF PLANTS. 



257 



THE ACCLIMATATION OF PLANTS. 



BY TUE EDITOR OF THE LONDON HORTICULTL'BAL MAGAZINE. 



Johnson, in his" Principles of Gardening," 

 treats tliis subject as seriously as if there 

 were anythin^^ in it but a chimera ; as if the 

 constitution of a plant could be permanent- 

 ly altered ; and after all, it is these great 

 theorists who mislead themselves first, and 

 their followers afterwards. In this case, 

 there is no new fact adduced. The old 

 humdrum tale about Aucuba japonica and 

 Pa/jiiia moutan having been stove plants, 

 removed first to the green-house, and then 

 out of doors, is of course resorted to as a 

 presumed confirmation of the doctrine of 

 the acclimatation of plants, as if it were 

 fact instead of fiction. 



So far as these illusions of great men 

 induce experiment, they are not without 

 their good effects. Mr. Johnson's error lies 

 in presuming that the mere fact of a plant 

 from a hot country being grown in the open 

 air, is indicative or proof of a change of the 

 plant or of its constitution, whereas it is 

 nothing more than the proof of its qualities 

 of endurance. He says, "Every plant has 

 a peculiar temperature, without which its 

 functions cease, but the majority of them 

 luxuriate most in a climate of which the 

 extreme temperatures do not much exceed 

 32 degrees and 90 degrees. No seed will 

 vegetate, no sap will circulate at a tempe- 

 rature at or below the freezing point of wa- 

 ter, yet the juices of the plant are not con- 

 gealed at a temperature far more depressed; 

 and I know of no other more satisfactory 

 proof, that, like a cold blooded animal — the 

 frog and the leech for example, it becomes 

 torpid, though life is not extinct, unless ex- 

 cited by a genial temperature." Something 

 very much bordering on our notions, which 

 are founded on practice, may be found in 

 Mr. Johnson's reasoning, but his conclu- 

 sions are altogether opposed to us. He 

 says, " no cultivation will render plants, 

 natives of the torrid zone, capable of bear- 

 ing the rigor of our winters, although their 

 offspring reared from seed may be rendered 

 much more hardy than their parents." 



We quite agree with this, because we 

 have shown and proved over and over again 

 Vol. II. 33 



that cultivation will not change the powers 

 of endurance either for heat or cold ; but 

 the steps which Mr. Johnson and other wri- 

 ters on acclimatation recommend, are per- 

 fectly right and proper to be taken, not as 

 they allege, to acclimatise the plant, but to 

 prove what it will endure. 



If the British oak were cultivated in a 



stove, [hot-house of high temperature] it 



would no more be a stove plant for that 



: operation, tlian a dog would be a horse for 



j being kept in a stable ; but an oak brought 



up in a stove, must not be planted out from 



I the stove to the open ground in rnid-winter, 



because the sudden check might kill it, and 



in all probability would kill it, though it is 



able to endure intense frost when properly 



! managed. Therefore, all plants to be grown 



in the open air, ought to be raised in the 



I open air, or if necessarily grown first in a 



I stove, should be gradually, instead of sud- 



I denly brought to lower temperature. 



Whoever can afford to lose plants, should 

 j try the experiment of their open air culture, 

 j because we may be growing in stoves and 

 ] green-houses many subjects that would 

 ' stand in the open ground in our winters. 

 j As Mr. Johnson very properly observes, 

 j " When a new plant arrives from tropical 

 latitudes, it is desirable to use every pre- 

 caution to avoid its loss ; but so soon as it 

 has been propagated from, and the danger 

 of such loss is removed, from that moment 

 ought experiments to commence ;" but in- 

 stead of saying, " to ascertain whether its 

 acclimatization is aitainahle^'' which he 

 does, he ought to say, to try what are its 

 powers of enduring cold, because that and 

 that only can have to be tried ; it is worse 

 than nonsense to talk of any change in the 

 powers of the plant being attained. It is 

 quite right to gradually bring the plant to 

 its proper trial, and not to do any thing 

 suddenly, because, as we have shown, the 

 oak itself might be reared in a stove and 

 grow there, and would be killed, if changed 

 from thence to out of door growth in mid- 

 winter. The nature of the plant is not 

 changed ; but it is the same with plants as 



