ON ACCLIMATISING GREENHOUSE PLANTS. 
35 
is, we fear, to be but little depended on, at least beyond a very limited extent. 
Future experience and observation, made without prejudice to any particular theory, 
may determine what is, at present, not well understood, but which it would certainly 
be a desideratum to be made acquainted with. 
Many greenhouse plants will not only attain a great size and resist the cold of 
our ordinary winters in one situation, while, in another, not a mile distant, the same 
species would be killed by the first sharp frost that occurs. Shelter is of much 
importance, and a poor, dry, or well-drained soil indispensable in attempting to 
cultivate tender plants in the open air of our climate. The common Laurel, which 
now flourishes in the most exposed situations, when first introduced to this country, 
was considered so tender, that the plant was covered over every night, during winter, 
with a blanket. The Laurel is no more hardy now than it was then; for had it been 
planted out in a moderately sheltered place, it would have stood the winter without 
that protection. 
"I find," says Mr. Street, in ' Horticultural Transactions,' "that poor, dry, and 
shallow earths and declivities are particularly well adapted to preserve many plants 
through the winter season. The quicker the superabundant fluid passes away from 
their roots the better. When excess of rain, or moisture, and severe frosts, happen 
nearly together, plants generally suffer much more than by dry frost. If the situa- 
tion of the plants be dry, frost does not hurt them so soon as if it were wet." Mr. 
S. conjectures that many plants are capable of enduring a more uncongenial climate 
or situation than that of their native place of growth ; and also that plants obtained 
from cuttings are better adapted for this purpose than those originated from seeds. 
In regard to the former of these opinions, we are perhaps not exactly aware of the 
circumstances under which they exist naturally ; and in regard to the latter, plants 
from cuttings may grow in some cases less luxuriantly than from seeds, and hence, 
the wood and buds become more fully ripened or matured, and consequently better 
able to resist the cold of winter. 
In planting out exotics, with the view to establish them as open-air plants, he 
prefers to plunge the pots into which they grow, leaving the hole in the bottom open 
for the escape of the roots, and also planting over drains, where the roots will be 
kept dry. 
In our own experience, we have found many exotics succeed by being left in the 
flower-garden borders during winter, having a thin layer of finely sifted coal-ashes 
laid over the surface of the ground as far round the stem as the roots were supposed 
to have extended. Covering others with a common flower-pot inverted over them, 
and occasionally during fine days removed, answered well with others. But the best 
and most convenient, as well as neatest manner, is covering them with large sea- 
kale pots, leaving the top or moveable part off generally during the day, and placing 
it on again during the night and in very frosty weather. Such plants as are planted 
out for this purpose, should be rendered dry at their roots, by placing under them a 
stratum of lime-rubbish, broken bricks, or small stones. This not only protects the 
