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NE W ENG L A N h K A KM K l{, 



JAN. 30, I'-.ffi. 



of too great an aliasemcnt of temperature.* — 

 Considered ii> this liglit the green-house may bo- 

 come one of the most useful, as well as ornamental 

 and pleasing sources of enjoyment to the experi- 

 mental horticulturist and the public generally. 

 * ^ We must not leave this part of the subject, 

 '^^illiout adverting to the advantages which may 

 I^R obtained- by artificial fecundations and impreg- 

 nations, of highly ornamental or useful exotic 

 plants, with more hardy species or varieties of the 

 same genus ; the produce of which may be highly 

 superior varieties, having all the beauty or excel- 

 lence of the tender species, and perhaps nearly 

 the same robustness of constitution as the hardy 

 one. We conceive it to be a method, by which, 

 now that artificial hybridizing is so well under- 

 stood, the most valuable results may in many in- 

 stances he produced in a coiii])aratively short 

 S|)ace of time. 



The choice of situation and as;!ect is another 

 important consideration in the naturalization of 

 plants. We never place a jdant of a delicate na- 

 ture in aspects exposed to the utmost inclemencies 

 of the weather — in situations Ojien to the fury 

 of the coldest winds, or the raging of the most 

 boisterous storms. We naturally seek on the 

 contrary to place them in a sheltered situation, in 

 an aspect favorably disposed to catch the genial 

 rays of the sun in suuuner, and to prolong as 

 much as possible the duration of that favorable 

 season. Hence the use of walls and trellises, and 

 the choice of particular aspects best calculated to 

 favor the object in view. In England, many fruits 

 require a wall, to come to maturity, which ripen 

 perfectly with us as standards, and although walls 

 are as yet but little used liere, we can easily im- 

 agine that many partially tender trees and shrubs, 

 might be brought to perfection upon them which 

 the inclemency of our winters forbids us to culti- 

 vate in the open air. 



Apart from shelters of this description, the 

 character of the soil and situation, demands the 

 utmost attention. Soils that are of a cold, clayey 

 and heavy texture, particularly if they retain wa- 

 ter, are totally unfit foi the growth of tender plants. 

 They should be planted in a light, friable and 

 porous soil, as dry as the peculiar constitution ot 

 the |)lant will admit, for not only is a wet soil 

 more liable to be deeply frozen, but also the ex- 

 posed parts of the plants which grow in it. Even 

 hardy and naturalized trees are often severely 

 aft'ected by the cold in a soil saturated with mois- 

 ture. The philosophy of this is well known to 

 every physiologist. In moist soils, the ))lant is 

 surcharged with watery fluid, the annual dejiosi- 

 tioiis of wood are large, but not firm and well 

 calculated to resist the intensity of cold ; the leaves 

 are Itonger completing their articulations with the 

 stem, and as a consequence of this the young 

 shoots are continued longer in a growingstate, and 

 remain succulent and unripened at the approach of 

 winter, when the first severe frost destroys their 

 vitality. Beside these facts, it is well known that 

 water (and the sap of plants in its primary state is 



•As a proof of the effects of a renewed reproduction from 

 seed, we may mention that we planted the present sea- 

 son in a favorable sitnntion a quantity of seed of the 

 Lima be;in, direct from its native country, lat. 14 deg. S. 

 — the plants produced, however scarcely attained tlie pe- 

 riod of flowering before they were destroyed by the frost, 

 whilst the plants in their immediate neigbbnrhood, the 

 produce of a variety of the same bean, natiyalized in the 

 country, yielded as usual abundant crops of matured 

 seed. 



but little more) is a better conductor of beat and 

 cold, than either the woody fibre of trees, or the 

 particles of air which occupy in some measure 

 the place of watery fluid, in a well ripened branch. 

 Susceptibility to injure by frost in ligneous plants, 

 is therefore increased with the presence of watery 

 fluid, and diminished by the ])resence of firm well 

 ripened aimual layers of wood. A knowledge of 

 this fact is of the ;.reatest importance to the agri- 

 culturist, in the selection of soils and situations for 

 crops which are but imperfectly naturalized. We 

 may illustrate this by remarking, that plantations 

 of the Chinese Mulberry, [Morus Midticaulis, a 

 tree that is JMStly exciting the greatest attention 

 in this country, and which deserves every eflTort 

 at comi)lcte naturalization,) which were situateil 

 upon dry gravelly soils, even if in cold aspects, 

 withstood almo.st perfectly the extreme rigors of 

 the last winter in the Eastern States, when exten- 

 sive fields of the same tree, in moist soils, were 

 entirely cut down to the ground-in a great major- 

 ity of instances. 



in Europe, the advantages of a dry soil for the 

 naturalization of plants are well known, both 

 theoretically and practically, and many plants that 

 formerly required the jirotection of a green-house, 

 are by the ))roper choice of dry and porous soi's, 

 inmired to the severity of ordmary winters. So 

 well is this subject understood in England and 

 France, that Camellias and Oranges have in fa- 

 Toruble situations been quite imturalized. In the 

 latter country it is quite remarkable how many 

 comparatively tender exotics, generally protected 

 in green-houses, are preserved perfectly in large 

 barn-like buildings, without the aid of fire, during 

 the whole winter. " The secret of this," Loudon 

 observes, " lies in the dryness of the air of France, 

 ami in the gardener having previously hy withhold- 

 ing water, matured the growth of the leaves and 

 ripened the wood; in short in his having reduced 

 the plants to a dormant stale before housing them." 

 In cases where it is desirable that the utmost pains 

 should be taken, as in the case of new and rare 

 shrubs, creepers, &c. the gardener will facilitate 

 the object in view by trenching the soil and arti- 

 ficially producing a dry subsoil by underlaying the 

 surface liiould with a strata of stones or very 

 coarse gravel : thereby checking too vigorous a 

 growth, causing a small but firm annual deposit of 

 wood, and jilacing the vegetable in a state of rest 

 long before the winter frosts commence. 



A variation of this mode of naturalizing, con- 

 sists ill placing many tender kinds of herbaceous 

 plants, and small shrubs upon dry rock-work or 

 affgregations of stones mingled with soil, where 

 they are found to thrive perfectly. We observed 

 in the Botanic Garden at Cambridge, Mass. an 

 Azalea indica, and a species of Erica, that had 

 braved the exceedingly low temperature of nearly 

 30 deg. [Fall.] below zero, the pastvvinter, having 

 been planted for several years previous in a mass 

 of rock-work, where they had annually matured 

 their wood in the most perfect manner. Those 

 persons who are acquainted with the comparative 

 delicacy of these ])lants, in a climate so cold as 

 that of Massachusetts, will appreciate at once how 

 thoroughly they had become naturalized by this 

 simple |)roces8. 



Naturalization by external protection, next de- 

 serves our attention. It is a common practice to 

 protect many shrubs and trees with a covering of 

 straw or mats at the approach of winter, during 

 their young state, knowing that as they become 



stronger and more bulky in size, they will also 

 acquire additional hardihood. This is an efl^ectiial 

 practice in its way, and we believe that considered 

 as an auxiliary in naturalizations, some useful 

 hints may be gathered in relation to it from recent 

 discoveries made in the physiology of plants. It 

 was formerly the opinion of some savans, among 

 others Hunter, S(dioe|i'and Salome, that vegetables 

 having a circulating system of fluids and a sort of 

 respiration ana'agous to those of animals, ought to 

 have therefore, and had, a property of develo[)in& 

 a certain quantity of caloric or heat within them- 

 selves. Recent experiments, however, made by 

 Schutzcr and Haider, and more latterly by Dr 

 Goeppert,* of the Botanic Garden, of Breslau, 

 seems to have proved, that "vegetables appear to 

 retain a certain medium temperature, which can 

 not however b& considered as originating from 

 heat evolved by the fiinctiims of the plant, but can 

 be satisfactorily explained by a reference to the 

 bad conducting power of the vegetable fibre, and 

 the wood by which the temperature of the sur- 

 rounding ferial strata, penetrates but slowly into 

 the interior of the plant."t What we would 

 wish to deduce directly from this, is that many 

 woody plants on which it is proposed to try accli- 

 matising experiments by external protection, might 

 in many instances with more chanc? of success, 

 be reared under shelter until they attained consid- 

 erable thickness of stem and induration of wood, 

 when they would from their increased non-con- 

 ducting capacity, be much better able to witlistand 

 the cold, if protected a few seasons, than the same 

 species, if reared from infancy in the open air. 

 As an illustration of the advantages which size 

 and diameter of stem give to tender trees in with- 

 standing rigorous cold, we may mention that we 

 saw in the nurseries at Philadelphia the follovvin"- 

 trees, viz. : Acacia julibrissin, Pinchneya pubens, 

 Magnolia grandiflora, and G. eliptica, Gordonia 

 ptibescens, ^c, of some twenty or more years 

 growth, that had survived uninjured during the 

 [)ast winter (unparalleled for depression of tempe- 

 rature for fifty years past), the extraordinary low 

 temperature of 12 (leg. or more below the zero of 

 Fab., or 44 deg. below the freezing point. That 

 this was owing in a great measure to their havin" 

 become naturalized in that locality, there can be 

 no doubt. But the ordinary lowest temperature 

 of Phi'adelphia is some 20 or 2.5 deg. above that 

 of the last winter, and we conceived that these 

 trees survived so perfectly the increase of cold 

 only by virtue of their large size, thickness of bark 

 and wood, and the consequent thickness of non- 

 conducting substance, to protect the juices of the 

 plant and the vital organs from the eftects of frost. 

 The simplest and perhaps most efiectual method 

 of |)reserviiig plants by external protection, is to 

 be found in the well known practice of envelop- 

 ing either the whole or a portion of the stem and 

 branches with a covering of dry straw, jiieces of 

 Russia matting, or moss and hay, firmly liound 

 with straw ropes. For small [dants, boxes or 

 empty casks, with a light in the top,- (or which is 

 preferable in the north side,) are often used. The 

 branches of evergreen trees, as the pine, hemlock 

 and spruce, where they can be procured, are ex- 

 cellent materials for this purpose. It is, we 

 believe, customary in some parts of France where 

 the fig is extensively cultivated, to bend the 



* Ubcr die Wcermt-Entwicken lung in den Pflanzen 

 ^'C , Breslau, 1830. 



t Jameson's Philosophical Journal. 



