ESCULENT-ROOTED PLANTS.— THE POTATO. 



215 



inference is, that, tinder all circumstances, 

 two crops, manured with guano, have been 

 saved out of three; that, if applied to 

 autumn and early spring-planted crops, it 

 is advantageous, but that it is dangerous 

 in late planting. The conclusion arrived 

 at in the use of farmyard manure is, that 

 if used abundantly in a very rank condi- 

 tion, and especially if applied in this state 

 to late-planted crops, it is an extremely 

 disadvantageous application. Ashes are a 

 safe manure when applied by themselves, 

 and crops have suffered little or nothing 

 by disease throughout Britain when ma- 

 nured with them alone, in the proportion of 

 27 to 4 ; and, when mixed with farmyard 

 dung, the success has been as 54 to 1 5 — 

 or that is, in the former case, 4 suffered 

 much, while 27 suffered little or nothing; 

 and in the latter, 15 suffered much, while 

 54 nearly escaped. Saline manures have 

 not been productive of injury, and are per- 

 haps beneficial. Without manure, the re- 

 sults are favourable as regards the disease. 

 In England, 32 cases suffered much for 96 

 which escaped; in Scotland, 1 suffered for 

 1 1 that escaped ; in Ireland, 1 for 7 ; and 

 in Wales, 1 for 2 — the whole giving 35 

 cases of suffering for 116 which escaped. 

 Nothing is discernible in favour of salt; 

 nor does sea-weed indicate a better effect. 

 The conclusion of the whole matter may 

 thus be summed up — That over-luxuri- 

 ance, arising from whatever cause, was 

 highly favourable to the progress of dis- 

 ease, and vice versa. 



Forcing. — The true ash-leaved kidney, Jack- 

 son's improved kidney, British queen, early ten- 

 weeks, Soden's early Oxford, early Manly, golden 

 dwarf, and others of a like early description, 

 should be chosen for this purpose, selecting 

 whole tubers of medium size, and placing them 

 close together, either in shallow boxes filled with 

 light rich sandy soil, or on the borders of an 

 early peach-house or vinery ; or, better still, 

 among half-decayed leaves placed on the surface 

 of a moderate hot-bed, one light of which will 

 be sufficient space to excite a sufficient number 

 of sets to plant a pit of 15 or 18 sashes — that is, 

 nearly 100 feet in length — of a 6-feet pit. The 

 genial heat from the leaves below will gradually 

 excite the tubers (but on no account must the 

 process be hurried, for too rapid excitement 

 would cause an undue excitability in the sap, 

 and greatly weaken the embryo shoots), while 

 the humidity arising from the leaves below will 

 prevent any loss taking place in the juices of the 

 plant by unnecessary evaporation, the young 

 roots of which will strike into the partially de- 

 cayed leaves which will adhere to them, and 



render their removal a safe and easy matter. 

 When the shoots have attained the height of 3 

 inches, they should be transplanted into a light 

 soil, laid 4 inches in thickness on the surface of 

 a bed of dung and leaves, in a slight state of 

 fermentation. We do not usually, unless the 

 heat is rather strong, cover the whole surface of 

 the bed at once with soil, but only lay it in 

 ridges across, about a foot apart, centre from 

 centre, and on these set the plants, filling up the 

 intervening spaces afterwards as the heat of the 

 bed declines, and as the roots extend. By this 

 means the heat from the bed has free means of 

 ascending upwards to warm the atmosphere of 

 the pit. The plants are set 4 inches apart in the 

 lines. It should be remarked, that a very slight 

 excess of bottom-heat is very prejudicial to this 

 plant, causing them to become, in a few days, 

 drawn up, slender, and etiolated in colour ; and 

 the same bad effect is produced by a deficiency 

 of ventilation. At the same time, cold must be 

 excluded, for few plants suffer sooner by frost 

 than this; covering the glasses nightly with felt, or 

 wooden shutters made to fit the sashes over which 

 they are to be placed (.vide fig. 789, and Sect. 5, 

 On covering the roofs of glass-houses and 

 pits, for the exclusion of cold or the reten- 

 TION of heat, &c, vol. i. p. 551), is a much better 

 precaution than employing extra heat in the bed. 



Although we have mentioned a bed of fer- 

 menting material, we do so, not that it is better 

 than, or even so convenient as, growing them in 

 a tanked pit (of which figs. 629, 631, and 632, 

 vol. i. pp. 450, 451, may be referred to as exam- 

 ples), which of all other modes is the best for all 

 sorts of kitchen-garden productions required at 

 an unseasonable period of the year. Indeed, for 

 all such purposes we expect to see the day when 

 long narrow borders shall be constructed, with 

 vaults under them, and these heated with hot- 

 water pipes, or having tanks of water circulating 

 under them. In such cases, all that is required 

 is an extent of common frames and sashes to be 

 placed over them, to cover in the whole surface. 

 In such borders, most of the productions of the 

 kitchen-garden may be brought to great matu- 

 rity. Beds of fermenting material can only be 

 advantageously employed when abundance of 

 leaves is conveniently to be had, or where tan- 

 ners' bark can be got for little less than carting 

 away. Either to purchase such material, or to 

 employ stableyard manure, would be a much 

 more extravagant process than even that of tank- 

 ing or vaulting the border, as noticed above. 

 The results never can be so satisfactory, on 

 account of the uncertainty of heat, and the 

 unnecessary amount of labour. Where there 

 are extensive lawns to keep in order, or where 

 the rotting down of tree- leaves is carried on — 

 for the purpose either of converting them into 

 manure, or employing them, when thoroughly 

 reduced, and mixed with sharp river-sand, as a 

 substitute for peat-earth for American plants — 

 then advantage may be taken of the process of 

 fermentation, and potatoes, pease, asparagus, 

 lettuces, &c, all requiring very little heat, may 

 be grown upon the masses. In this way we 

 employ leaves to a great extent. As they are 

 gathered from the lawns and drives, they are 



