282 . 



provided in different parts of the nursery, with plenty of corn under them, and we 

 doubt if they would stay in the grass, and gnaw the trees for a subsistence. In 

 the spring, remove the straw and destroy the mice. Where mulching is used, it 

 will not be necessary to sov\^ the oats; and if the refuse grain or weeds grow up 

 through the mulching, another coat of straw can be added; or among wide 

 rows, the straw, weeds and all, ploughed under. 



4. A mechanical freezing down of the extremities — a well known form of 

 injury from cold, to which most trees and plants are more or less subject ; but more 

 especially when they make a late, rank, unripe growth. Hence the great preven- 

 tive to this, and, in fact, the grand desideratum, the neplus-ultra of horticultural 

 success in a severe climate is to secure a Jinn, ripe, mature growth, with a per- 

 fect terminal bud at the end of every shoot — which in some autumns here can 

 never, or with great dificultg, be secured on yaung trees if grown on a poor, 

 weak soil, or a late cold soil, be it rich or poor. This form of injury is harm- 

 less on the apple compared with the next one, though the apple and most fruit 

 trees are subject to a troublesome modification of it, occurring when a late growth 

 is followed by a severe winter, which, though it may not kill tlie branches, so 

 chills and enfeebles their extremities, that the sap on the I'eturn of the growing 

 season will not flow freely and strongly to those extremities, but prefers to push 

 out new shoots from below, thus causing many troublesome sprouts, and giving 

 the top a dwarfish, stinted appearance. This can doubtless be aggravated by 

 planting on bleak, exposed situations, where the winds are more piercing and 

 drying. Hence the importance in this windy country of suitable protection in 

 the way of woodlands or artificial screens around orchards and nurseries, more 

 especially on the N. and W. These, for many reasons, cannot be too strong'y 

 urged upon our cultivators, and are very easily grown from the peach, the locust, 

 or the abele — the evergreens when " got up" are far preferable. The cultivation 

 of trees should utterly cease by the first of August, unless the trees are to le 

 taken up in the fall, when it may be continued till the first of September, with 

 perhaps, even in that case, rather doubtful advantage. When the growth is ii- 

 clined to be too late, great benefit may be derived from clipping off the ends rf 

 the shoots from one to four inches during the first half of October, 



5. Heart-blight — the corruption of the heart-wood, or pith of fruit-trees, moi3 

 particulaily the apple — caused by the frost, or alternations of freezing and thaw- 

 ing, producing a chemical change or decomposition of the unripe sap in the tissue, 

 thereby rendering it poisonous and unfit for circulation. The prime cause woull 

 then seem to be an immature growth, because other things being equal, if th' 

 growth were perfect the extremities would naturally suffer first, whereas the sea 

 of this injury is the heart-wood, or pith. This fact would seem to indicate, tha 

 when a late growth is stopped by frost the sap gathered at the heart, or that tb 



