HOKTICULTURE [VEGETABLES. rapa, is a biennial, the upper part of whose stem swells into a round fleshy mass, resembling a turnip, but produced above ground. Kohl Rabi is exceedingly hardy, withstanding both severe frosts and drou Mt. It is not much grown in English gardens, though when used young it forms a good substitute for turnips. The seeds should be sown in May and June, and the seedlings should be planted shallowly in well-manured ground, 8 or 10 inches apart, in rows 15 inches asunder; and they should be well watered, so as to induce quick growth. The bulbs will be lit for use when they are as large as not larger than an early turnip. The best sorts are Early White Vienna, and Early Purple Vienna. 168. The Leek, Allium Porrum, a hardy biennial, is said to be a native of Switzerland, but more probably comes from the East. The leeks, which prefer a light soil, are sown in beds about the middle of March, and later for a succession, and in June or July are planted out 6 inches asunder; and in rows 15 or 18 inches apart. When the weather is moist the plants are dropped upright into the hole made by the dibble, and no more earth than will just cover the fibres is allowed to fall in, the hole being left open to encourage the stem to swell out, and blanching is effected gradually by the earth washing into the hole. They are also planted in trenches like celery, and earthed up when they have made their growth. The leeks will be fit for use in September, and will last till the spring. The best sorts are Early Netherlands, for early use; Large Rouen, one of the very best ; London Flag, and Musselburgh, the latter being reputedly the hardiest; and Carentan, a very large hardy French sort. 169. The Lettuce, Lactuca sativa, is a hardy annual, highly esteemed as a salad plant, while its milky juice forms the lactucarium of the materia medica. The London market-gardeners make pre paration for the first main crop of Cos lettuces in the open ground early in August, a frame being set on a shallow hotbed, and, the stimulus of heat not being required, this is allowed to subside till the first week in October, when the soil, consisting of leaf- mould mixed with a little sand, is put on 6 or 7 inches thick, so that the surface is within 4 inches of the sashes. The best time for sowing is found to be about the llth of October. When the seeds begin to germinate the sashes are drawn quite off in favourable weather during the day, and put on, but tilted, at night in. wet weather. Very little watering is required, and the aim should be to keep the plants gently moving till the days begin to lengthen. In January a more active growth is encouraged, and in mild winters a considerable extent of the planting out is done, but in private gardens the preferable time would be February. The ground should be light and rich, and well manured below, and the plants put out at 1 foot apart each way. In planting at this early season, the dibble, in closing in the soil, should be inserted on the south side of the plant. Frequent stirring of the ground with the hoe greatly encourages the growth of the plants. A second sowing- should be made about the 5th of November, and a third in frames about the end of January or beginning of February. In March a sowing maybe made in some warm situation ; succcssional sowings may be made in the open border till August, about the middle of which month a crop of Brown Cos and Hardy Hammersmith should be sown, the latter being the most reliable in a severe winter. These plants may be put out early in October on the sides of ridges facing the south or at the front of a south wall, beyond the reach of drops from the copings, the Hardy Hammersmith being planted 6 or 8 inches apart. Young lettuce plants should be thinned before they crowd or draw each other, and transplanted as soon as possible after two or three leaves are formed. Some cultivators prefer that the summer crops should not be transplanted, but sown where they are to stand, the plants being merely thinned out ; but trans planting checks the running to seed, and makes the most of the ground. Forcing. For a winter supply by gentle forcing, the Hardy Hammersmith and Brown Dutch Cabbage lettuces, and the Brown Cos and Green Paris Cos lettuces, should be sown about the middle of August and in the beginning of September, in rich light soil, the plants being pricked out 3 inches apart in a prepared bed, as soon as the first two leaves are fully formed. About the middle of October the plants should be taken up carefully with balls attached to the roots, and should be placed in a mild hotbed of well-prepared dung (about 55) covered about 1 foot deep with a compost of sandy peat, leaf-mould, and a little well-decomposed manure. The Cos and Brown Dutch varieties should be planted about 9 inches apart. Give plenty of air when the weather permits, and protect from frost. There are two races of the lettuce, the Cos lettuce, with erect oblong heads, and the Cabbage lettuce, with round or spreading heads, the former generally crisp, the latter soft and flabby in texture. Some of the best lettuces for general purposes of the two classes are the following : - Cos : White Paris Cos, best for summer ; Green Paris Cos, hardier than the white ; Alphange Cos, stands well ; Brown Cos, one of the hardiest and best for winter ; Hicks s Hardy White Cos ; Sugarloaf Bath Cos. Cabbage: Hammersmith Hardy Green, very hardy, good for winter ; Tom Thumb ; Brown Dutch ; Neapolitan, best for summer ; Grand Admiral, stands the winter well ; Stanstead Park. 170. The Mushroom, Agaricus eampestris, is a well-known fun- Mush- gus of a specially savoury character ; it grows wild in Great Britain room, on upland pastures, and appears to be indigenous to most regions of the globe. The plant is propagated by spores, the fine black dust seen to be thrown off when a mature specimen is laid on white paper or a white dish ; these give rise to what is known as the spawn " or mycelium, which consists of whitish threads permeatino- dried dung or similar substances, and which, when planted in a proper medium, runs through the mass, and eventually appears in the form of the mushroom. This spawn may be obtained from old pastures, or decayed mushroom beds, and is purchased from nurserymen in the form of bricks charged with the mycelium, and technically known as mushroom spawn. When once obtained, it may, like leaven, be | indefinitely preserved. It may be produced by placing quantities of horse dung saturated with the urine of horses, especially of stud horses, with alternate layers of rich earth, and covering the whole with straw, to exclude rain and air ; the spawn commonly appears in the heap in about two months afterwards. The droppings of stall-fed horses, or of such as have been kept on dry food, should be made use of. The old method of growing mushrooms in ridges out of doors, or on prepared beds either level or sloping from a back wall in sheds or cellars, may generally be. adopted with success. The beds are formed of horse droppings which have been slightly fermented and fre quently turned, and may be made 2 or 3 feet broad, and of any length. A layer of dung about 8 or 10 inches thick is first deposited, and covered with light dryish earth to the depth of 2 inches ; and two similar layers with similar coverings are added, the whole being made narrower as it advances in height. When the bed is finished, it is covered with straw to protect it from rain, and also from parching iniluences. In about ten days, when the mass is milkwarm, the bed will be ready for spawning, which consists of inserting small pieces of spawn bricks into the sloping sides of the bed, about 6 inches asunder. A layer of fine earth is then placed over the whole, and well beaten down, and the surface is covered with a thick coat of straw. When the weather is temperate, mushrooms will appear in about a month after the bed has been made, but at other times a much longer period may elapse. The principal things to be attended to are to preserve a moderate state of moisture and a proper mild degree of warmth ; and the treatment must vary accord ing to the season. Mr Cuthill describes a very simple mode of culture. The ridge is built up of dung as it is brought fresh from the London stables ; in this fermentation soon sets in, and, when the heat of the bed declines to 80, pieces of spaw r n bricks are inserted, a foot apart, in the sides of the bed, which is then moulded over, 2 inches thick, pressed with the feet, and beaten with the spade, then watered, and beaten again with the spade, and finally smoothed down. The more the mould is pressed, the finer the crop, and the more solid the texture of the mushroom. These ordinary ridge beds furnish a good supply towards the end of summer, and in autumn. To command a regular supply, how- j ever, at all seasons, the use of a mushroom-house (see par. 13, 1 p. 226) will be found very convenient. The material employed in all cases is the droppings of horses, which should be collected fresh, and spread out in thin layers in a dry place, a portion of the short litter being retained well moistened by horse urine. It should then be thrown together in ridges and frequently turned, so as to be kept in an incipient state of fermentation, a little dryish friable loam being mixed with it to retain the ammonia given off by the dung. With this or a mixture of horse-dung, loam, old mushroom-bed dung, and half-decayed leaves, the beds arc built up in successive layers of about 3 inches thick, each layer being beaten firm, until the bed is 9 or 10 inches thick. If the heat exceeds 80, holes should be made to moderate the fermentation. The beds are to bo spawned when the heat moderates, and the surface is then covered with a sprinkling of warmed loam, which after a few days is made up to a thickness of 2 inches, and well beaten down. The beds made partly of old mushroom-bed dung often contain sufficient spawn to yield a crop, without the introduction of brick or cake spawn, but it is advisable to spawn them in the regular way. The spawn should be introduced an inch or two below the surface when the heat has declined to about 75, indeed the bed ought never to exceed 80. The surface is to be afterwards covered with hay or litter. The atmospheric temperature should range from 60 to 65 till the mushrooms appear, when it may drop a few degrees, but not lower than 55. If the beds require watering, water of about 80 should 1)0 used, and it is preferable to moisten the covering of litter rather than the surface of the beds themselves. It is also beneficial, especially in the case of partially exhausted beds, to water with a dilute solution of nitre. For a winter supply the beds should be made towards the end of August, and the end of October. 171. The Mustard, Sinapis alba, or Brassica alba, is a hardy annual, Mustai used as a small salad generally accompanied by garden cress while still in the seed-leaf. To keep up a supply, the seed should be sown every week or ten days. The sowings in the open ground may be
made from March till October, earlier or later according to the
