The potato, although it most fortunately produces its tubers freely in our climate, must be considered as rather a delicate plant. Its leaves are blackened by the first ap proaches of frost in the autumn. Every body knows how apt potatoes kept in the house or cellar are to be injured by frost. The best means of guarding against this evil in these places are, to bring in potatoes in as clean and dry a state as possible, and, when risk of frost is appre hended, to place over them a covering of straw at least a foot thick.
It is well known, that if any of the larger sorts of po tatoes of the former year's growth be kept in the cellar till May or June, they never fail to shoot, producing both roots and runners ; but it is not perhaps generally known, that if these be carefully placed in boxes among decayed tree-leaves or other very light vegetable mould, and still kept in the cellar, they will yield a crop of small potatoes about mid-winter. A small supply may thus be procured by way of curiosity ; but the potatoes are rather watery, and quite deficient in flavour.
In private gardens of a superior order, the first early potatoes are in some measure forced. In February two or three slight hot-beds are formed, and the potatoes are plant ed thickly on these. They are hooped over, and covered with mats at night and in bad weather. The more air they have the better, provided frost do not get leave to nip them. They require moderate but regular watering, par ticularly in March, when there is generally some dry weather. The young tubers are gathered in April and May in succession as they are formed.
310. Many persons amuse themselves with raising seedling potatoes. Sonic of the largest, first produced, and thoroughly ripened berries, are gathered from several different good varieties ; these may be preserved in dry sand till spring ; or the seeds may be immediately sepa rated from the pulp, and kept in paper-bags over winter. In April the seed is sown, in any fine light soil, in drills half an inch deep, and perhaps a foot asunder, keeping the kinds carefully separate, and marking them with tallies. When the plants rise, they are thinned out to six inches apart. They are kept clear of weeds, and once or twice earthed up. When the haulm decays, the tubers are taken up ; they are carefully preserved from frost during the winter ; and being planted next spring, the crop which re sults will determine the qualities of the different kinds. They should be boiled separately, and regard had to their flavour, mealiness or waxiness, size, shape and colour. When the seed of early varieties can be procured, it is, for different reasons, to be preferred. Mr Knight suspected the cause of these early varieties not producing flowers to be the preternaturally early formation of the tubers, draw ing off for their support that portion of sap which should have gone 'to the production of the blossom. He there
fore devised means for preventing the formation of tubers ; and when this was accomplished, he found no deficiency in the production of flowers and berries. The means were having fixed strong stakes in the ground, he rais ed the mould in a heap round the bases of them ; on the south side he planted the potatoes. When the plants were about four inches high, they were secured to the stakes with shreds and nails, and the mould was then washed away with a strong current ol water from the bases of their steins, so tnat the fibrous roots only entered the soil, and no run ners or tubers could be produced.
311. The disease called curl has in many places proved extremely troublesome and injurious. It has given rise to much discussion, and to detail all the various opinions would be a useless task. It may, however, be remarked, that the experiments of Mr Thomas Dickson (Scottish Horticultural Memoirs, i. 55.) sheer, that it arises Iron) the vegetative powers in the tuber planted having been ex hausted by over•ripening. That excellent horticulturist observed, in 1808 and 1809, that cuts taken from the waxy, wet, or least ripened end of a long flat potato, that is, the end nearest the roots, produced healthy plants ; while those from the dry and best ripened end, farthest from the roots, either did not vegetate at all, or produced curled plants. This view is supported by the observations of a very good practical gardener, Mr Daniel Crichton at Minto, who, from many years experience, found p. 440.) that tubers preserved as much as possible in the wet and immature state, and not exposed to the air, were not subject to curl. And Mr Knight (in Lond. Hort. Trans. for 1814) has clearly shown the beneficial results of using, as seed-stock, potatoes which have grown late, or been imperfectly ripen ed, in the preceding year. Mr Dickson lays down some rules, attention to which, he thinks, would prevent the many disappointments occasioned by the curl. He re commends, 1. The procuring of a sound healthy seed stock (stock of tubers for planting) from a high part of the country, where the tubers are never over-ripened 2. The planting of such potatoes as are intended to supply seed stock for the ensuing season, at least a fortnight later than those planted for a crop, and to take them up whenever the stems become of a yellow green colour, at which time the cuticle of the tubers may be easily rubbed off between the finger and thumb. 3. The preventing those plants that are destined to yield seed stock for the ensuing year, from producing flowers or berries, by cutting off the flower buds ; an operation easily performed by children, with a sickle, at a trifling expellee.