478 



JOURNAL OF HOETICULTUEE AND COTTAGB GARDENER. 



[ Jtme 13, 1872. 



are allowed to re-enter, and these are only removed from the 

 inside of the house to the outside of it, as they are placed 

 during August and September against the front wall outside, 

 where they are fully exposed to the sun. 



Another advantage is that a large portion of the tan may he 

 removed without disturbing the plants at all ; and when the 

 danger of overheating is not very great, it is much better that 

 they should not be moved at all, as, however carefully the work 

 is executed, a partial loosening at the neck always takes place, 

 especially with large plants. To avoid this and the cousecjuent 

 rupture of some of the roots, I have been in the habit of pull- 

 ing out the tan from between the pots with something like a 

 garden hoe or coal rake. The plants are rarely plunged more 

 than 4 inches deep at first, on account of the danger of over- 

 heating, but even at that depth I have known injury done, 

 and as they are usually placed quincunx fashion, the tan has 

 to be drawn out diagonally ; but unless the heat is very violent, 

 drawing out the tan in one direction is usually sufficient. It 

 is merely allowed to lie on the path a few days — a week or 

 so — untU the heat subsides, when it is put back again. By 

 careful management the tan may be withdrawn until furrows 

 are made several inches below the bottoms of the pots, so that 

 the latter are not liable to overheating ; but as it is always 

 better when a steady instead of a violent heat can be secured at 

 first, I endeavour to have any new tan that may be required 

 dried a little previous to use. In summer there is no difficulty 

 in this, but in winter it is not so easily done. However, where 

 a dry floor under cover can be secured it will diy considerably in 

 a few days ; moreover, if the heat in the old tan be found 

 pretty good, it is better not to add too much to it in turning, 

 but to place the new at top. It is astonishing how long old 

 tan win retain its heat, even when it is reduced to a very fine 

 leaf-monld-like material ; but it is better on all occasions, if 

 possible, to prevent its ever heating so as to scald itself into a 

 white or dry condition. 



I need hardly say, that in turning or mixing the tan bed the 

 same plan is adopted as in trenching ground, new tan being 

 added in the same manner as dung is in the latter case, un- 

 less there is reason to think it will overheat, when the new 

 tan is best placed on the top. Another method I have adopted 

 with some advantage is, when the bed is being turned, to in- 

 sert draining pipes at various places in the bed. Small 2-inch 

 pipes will answer, and if a stake be placed inside them to keep 

 them upright, about three pipes will usually do at a spot. 

 These act as flues, and although somewhat in the way when 

 the plants are plunged, they can usually be pushed a little 

 aside to allow the pot a place. I have found them very useful, 

 and, though not much seen, they are not unsightly. 



As regards the tan used I can give but little information ; 

 many years ago I had occasion to use some that was very un- 

 satisfactory, as it did not seem inclined to heat at all. At the 

 time I suspected chemicals had been used in the tanpit, but 

 whether this was so or not I cannot say ; certainly what I have 

 had lately has not been f.aulty in this respect. When pur- 

 chasing tan it is well to insure that it is fresh, and has not 

 been lying in a large heap in which it may have heated to ex- 

 cess and become exhausted. Secure what is wanted before- 

 hand, have it fresh and dry, and sweeten it at home. In fine 

 weather, if it be spread a foot or less thick on dry clean ground, 

 say on a pavement or macadamised road, and turned once or 

 twice a-day, heaping it up at night and throwing mats over it 

 if there be danger of rain, it will soon be dry enough for use ; 

 but when an entirely new bed has to be madegreat care should 

 be taken against overheating. It is in this case advisable to 

 use a comparatively small quantity of tan, and add more as 

 required ; or if the bulk is well mixed, heated, and tui-ned out- 

 doors before being brought in, so much the better. Even 

 then care must be taken that it do not become too hot, as tan 

 is sometimes treacherous in this respect, and total destruction 

 is not unfrequently the consequence. Wherever a number of 

 Pines with overgrown crowns and fruit of small size are to be 

 seen, overheating will generally be found to have been the 

 cause ; therefore, as soon as the bed is finished and the plants 

 all in their places, put in some sticks at various places, and 

 examine them every day, or more than once a-day after the 

 fii'st three or four ; a Uttle practice wiU enable anyone to jud<»e 

 how much warmth is useful and how much dangerous without 

 the aid of the thermometer. If, however, there be any doubts, 

 this instrument may be used, and may be inserted to a suffi- 

 cient depth in the bed to insure its being affected by the heat, 

 which, if exceeding 90', may be pronounced dangerous, but it 

 very often rises much, higher ; I have known it reach 140% 



when, of course, immediate action became necessary ; in fact, 

 the plants had been removed before it even approached that 

 point. Sudden rises in the bottom temperatm-e are not un- 

 common where tan is used, and in consequence some good 

 Pine-growers avoid its use altogether, and content themselves 

 with leaves alone or fire heat. I must say, however, that I 

 have, perhaps, a weakness for tan, and am unwilling to abandon 

 its use when its excessive heat can be checked by the means 

 described. 



Leaves. — The leaves of Oak, Beech, and Sweet Chestnut givfr 

 a steady, long-continued heat ; they never become too hot, and 

 rarely too cold. Many Pine-growers prefer them to tan, and the 

 mild heat they afford seems to be more agreeable to vegetation 

 than any artificial heat from fire and water ; but it is, perhaps,, 

 not so great as is necessary in some cases where Pine suckers 

 have to be urged into fruit in twelve months. A leaf-bed is of 

 great assistance in Pine-growing, and when supplemented with 

 plenty of hot-water pipes for top heat, all will go on well ; and 

 in couutiy places at great distances from a lanyard, and where 

 tree leaves are good and plentiful, they may be used with a 

 good result. The leaf-bed must, however, be deeper than the 

 tan bed, or capable of containing more, as quantity is essential. 

 Care must also be taken in collecting the leaves, so that they 

 may not be mixed with those of the Lime, Elm, Sycamore, 

 and several others, which are far inferior to Oak and Beech 

 leaves. The latter, in my opinion, are the best — better than 

 the Sweet Chestnut leaves, but these are not to be despised,, 

 and, being larger, are collected with greater ease than the others. 



When the Pine plants are plunged in the leaf-bed the pots 

 may be buried up to their rims, as there is no fear in general 

 of leaves overheating, and an inch or two of tan on the top 

 gives a better face to the whole. Some, in fact, use about a 

 foot of tan over the leaves — sufficient for entirely plunging the 

 plants. This the grower may please himself about. Tan is 

 certainly a more agi'eeable material to work in, but in the case 

 of mere plunging it exercises no particular influence on the 

 plant. 



Bed-heating by Hot Water. — There are v.arious modifi- 

 cations of this mode of applying heat ; the most common is to 

 have two or more horizontal pipes some distance apart, in a. 

 chamber with a floor above, on which tan, cocoa fibre, or some 

 other plunging material is placed, or they may be covered with 

 rubble, with smaller stones on the top, some dui'able kind of 

 litter over the top of these, and then the plunging material, or 

 the sou in which the Pines are planted. This mode of apply- 

 ing bottom heat is better adapted for Pines than for very early 

 Vines, for it is seldom that much forcing at the root is good 

 for them ; but very good Pines are often grown in this way,, 

 both in pots and planted out. The evils of the latter method 

 are, that there is no control over the fruiting, and Queens, 

 in particular, are so prone to form suckers, that the plan as a 

 whole is less practised now than it was twenty years ago. It 

 must be acknowledged that the diy bottom heat thus afforded 

 differs widely from the nice moist heat supplied by such fer- 

 menting materials as tan or leaves, and the substitution of the 

 open trough for the closed-up pipe has often led to the oppo- 

 site extreme. Some, it is true, have a hot-water pipa placed 

 inside a trough of water, and the heat thus applied is sufficient 

 to warm the water in the trough to the requisite temperature,, 

 and it is evaporated as requii-ed. Sometimes, also, the water 

 can be di'ained-oft' entirely when a dry heat is wanted, but com- 

 plicated apparatus are always getting out of order. Bottom 

 heat so apphed has been turned to the best account by nursery- 

 men and others, and I know that excellent Pines are so grown; 

 and as the heating here is more under command than in the 

 cases where fermenting material is used, hot water commends 

 itself to the many, to whom coals and cast iron are more 

 familiar than tree leaves and tan. 



Although bottom heat is very essential for the Pine Apple, 

 atmospheric heat is equally necessary, and the requisite num- 

 ber of pipes to heat the atmosphere surrounding the plants 

 must be supijhed. It is thought good practice to arrange the 

 heating apparatus so that the whole heating power can be 

 thrown either into the top or bottom heating pipes as may be 

 necessary. In a cold winter's night it may be of advantage to 

 heat the atmosphere as much as possible, while in hot sum- 

 mer weather the bottom heat only will be wanted, and by 

 means of stop-taps, &c., this may be accomplished with but 

 veiy Uttle trouble. 



With regard to the character of the boilers and pipe-connee- 

 tions, I shall merely observe that the inexperienced should rely 

 on known good apparatus rather than try novelties, which aie 



