ACCLIMATATION OF PLANTS. 



259 



these days condescend to enlighten us rather 

 more upon this subject, and inform us how 

 there could be any doubt. The i'mus lla- 

 veaiia, teocote, patula, and hartwegii, are 

 known hardy plants, and were introduced 

 from Mexico as such, and we should like to 

 know how they could be other than hardy 

 from a climate like that experienced at the 

 top of a mountain 8,000 feet high. 



The Coniferce of Mexico require no ac- 

 climatising, as it is called. There can be 

 no doubt that they have to endure greater 

 hardships on the mountains of Mexico, than 

 they do in our ordinary winters ; but this 

 has nothing to do with the question of ac- 

 climatation. We have all through main- 

 tained that it is impossible to alter in any 

 plant its powers of endurance. The only 

 way properly to ascertain a plant's powers 

 of endurance, is to gradually change its 

 temperature, until it is placed in the open 

 ground ; and to select several positions, 

 even those of different circumstances, as 

 north, south, east and west aspects, with a 

 registering thermometer at each place. 



77ie co?iditio?is most favorable to a plant 

 arc those which involve the hast change, and 

 that change the most gradual. It mil often 

 bejound, that when there is no protection^ a 

 plant under a south wall, or a south-west, 

 well perish, while one in a rwrthernor north- 

 eastern exposure loill survive ; the one never 

 being so greatly excited as the other, is con- 

 stqaently never subject to such great changes, 

 and hence its e?idura?ice. The plant placed 

 in the coldest aspect, having iw sun to act 

 upon its frozen juices, gradually thaivs ; 

 while that which is subject to the immediate 

 operation of a hot sun, which frequently suc- 

 ceeds a frost, is often very suddenly acted 

 upon* But there are circumstances under 

 which plants may succeed better than they 

 generally do, and among them there are 

 certain conditions that can be supplied : for 

 instance, gravelly bottom, good drainage, 

 poor compost, shelter fi|om the northeast 

 winds, are all favorable to a plant that is 

 susceptible of injury from cold ; not that 

 these circumstances alter the plant, but they 

 change the nature of what it has to bear. 

 The gravelly bottom is always warmer, the 



* We have italicised this passage as containing the pilh 

 of all practical knowledge ia Ihe treatmeut of half hardy 

 planu. — Ed. Hoai. 



good drainage always tends to the same 

 end, the poor soil keeps the plant from 

 growing too rapidly, and the shelter is of 

 the greatest consequence ; but if, notwith- 

 standing all these circumstances the winter 

 is severe enough to overcome them, the 

 half hardy plant that would go through 

 some winters will perish. It will bear no 

 more hardship, after all that can be done 

 for it, than it would have borne without so 

 much coaxing, because all that has been 

 done only changed the hardships it had to 

 go through, and not the constitution of the 

 plant itself. 



But let us now consider how far, accord- 

 ing to Mr. Johnson's notions, the offspring 

 of tropical plants raised from seed may be 

 rendered much more hardy than their pa- 

 rents. Now we deny that a seedling can 

 be rendered more hardy than the parents ; 

 although we do admit that seedlings 7}iay 

 be more hardy than their parents. Our 

 opinions are founded on this one fact • — 

 Among plants known to be tender, the 

 dahlia, potato, and some other subjects, 

 something has been done in the way of 

 seedlings, and in a batch of man}', some 

 will be found affected with the frost more 

 than others. Among broccoli, cauliflowers, 

 and some other subjects, it is known that 

 the seedlings will in some cases differ from 

 the parent — some will endure the winter 

 better, some come earlier, some stand bet- 

 ter ; in short, it is not at all uncommon to 

 see a visible change in many of the plants. 

 The new varieties of peas, cabbages, cau- 

 liflowers, broccoli, turnips, melons, cucum- 

 bers, and all kinds of fruit, have been ob- 

 tained from seed, and the constant varia- 

 tions to be found in seedlings from a known 

 parent, show us distinctly that it is fair to 

 hope, that in a limited degree there may be 

 a progeny somewhat more hardy than the 

 parent. 



We were once going through an immense 

 piece of broccoli, after the extreme hard win- 

 ter so oftencalled Murphy's,when on or about 

 the 11th of January, there was the hardest 

 frost known in England. It was as diffi- 

 cult to find a bit of vegetable alive as if 

 every thing had been burned up. On this 

 occasion, there were, among a wreck of 

 thousands of plants, which were rotten and 



