Preparation of Ground.—The routine cultivation must begin with a thorough preparation of the ground. Efficient drainage is imperative, for stagnant water in the subsoil is fatal to the plant. But a rich loam does not need the extravagant manuring that has been recommended and practised. Deep digging and, where the subsoil is good, trenching may be recommended, but an average manuring will suffice, because Asparagus can be effectually aided by annual top-dressings, and proper surface culture is of great importance in the subsequent stages. It is necessary to choose an open spot for the plantation. Preparation of the ground should commence in the autumn and be continued through the winter, a heavy dressing of half-rotten stable manure being put on in the first instance, and trenched in two feet deep. In the course of a month the whole piece should be trenched back. If labour is at command a third trenching may be done with advantage, and the surface may be left ridged up until the time arrives to level it for seeding. It will be obvious that this routine is of a somewhat costly character, but we are supposing the plantation is to remain for many years, making an abundant return for the first investment. Still we are bound to say that a capital supply for a moderate table may be obtained by preparing a piece of good ground in an open situation in a quite ordinary manner with one deep digging in winter, adding at the time some six inches or so of fat stable manure, and leaving it thus until the time arrives for sowing the seed. Then it will be well to level down and point in, half a spade deep, a thin coat of decayed manure to make a nice kindly seed-bed.
Where soil known to be unsuitable, such as a damp clay or pasty loam, has to be prepared for Asparagus, it will be found an economical practice to remove the top spit, which we will suppose to be turf or old cultivated soil, and on the space so cleared make up a bed of the best possible materials at command. Towards this mixture there is the top spit just referred to. Add any available lime rubbish from destroyed buildings, sand, peat, leaf-mould, surface soil raked from the rear of the shrubberies, &c., and the result should be a good compost obtained at an almost nominal cost.
Size of Bed, and Sowing Seed.—At this juncture several questions of considerable importance arise. And first, whether the crop shall be grown on the flat or in raised beds. Where the soil is sufficiently deep, and the drainage perfect, the flat system answers well. The advantages of raised beds are that they deepen the soil, assist the drainage, promote warmth, and thus aid the growth of an early crop. In fact, raised beds render it possible to grow Asparagus on soils from which this vegetable could not otherwise be obtained. The preparation is the same in either case, and therefore we shall make no further allusion to flat beds, but leave those to adopt them who find their soil and requirements suitable. Now comes the question of distance, on which depends the width of the beds. The first point may be settled by the measure of the plant, and the second by the measure of the man. Monster sticks are valued at some tables, and we shall refer to these later on, but an abundant crop of handsome, though not abnormal, Asparagus meets the requirements of most households. After many experiments, we have come to the conclusion that the best mode of insuring a full return of really good sticks, with the least amount of labour, is to lay out the land in three-feet beds, with two-feet alleys between. In some instances, no doubt, five-feet beds, containing three rows of roots, one down the middle and one on each side at a distance of eighteen inches, are preferable. For the majority of gardens, however, the three-feet bed is a distinct advantage, were it only for the fact that all excuse for putting a foot on the bed is avoided. On this narrow bed only two rows of plants will be necessary. Put down the line at nine inches from the edge on both sides, and at intervals of fifteen inches in the rows dibble holes two inches deep, dropping two or three seeds in each. This will give a distance between the rows of eighteen inches. In very strong land, heavily manured, the holes may be eighteen inches apart instead of fifteen. April is the right month for sowing.
Thinning.—When the ‘grass’ from seeds has grown about six inches high, only the strongest plant must be left at each station, and they should finally stand at a distance of fifteen or eighteen inches in the row. Much of the injury reported to follow from close planting has been the result of carelessness in thinning. The young plant is such a slender, delicate thing, that, to the thoughtless operator, it seems folly to thin down to one only. The consequence is that two or three, or perhaps half a dozen, plants are left at each station to ‘fight it out,’ and these become so intermixed as to appear to be one, though really many, and of course amongst them they produce more shoots than can be fed properly by the limited range of their roots. Severe, or may we say mathematical, thinning is a sine quâ non, and it requires sharp eyes and careful fingers; but it must be done if the Asparagus beds are to become, as they should be, the pride of the Kitchen Garden.
Blanching.—The grave question of white versus green Asparagus we cannot entertain, except so far as concerns the cultivator only. On the point of taste, therefore, we say nothing; and it is a mere matter of management whether the sticks are blanched to the very tip, or allowed to become green for some few inches. Blanching is effected in various ways. The heaping up of soft soil, such as leaf-mould, will accomplish it. On the Continent many contrivances are resorted to, such as covering the heads with wooden or earthen pipes. In a few districts in France champagne-bottles with the bottoms cut away are employed. But a strong growth being secured, the cultivator will find it an easy matter to regulate the degree of colour according to the requirements of the table he has to serve. As a rule, a moderately stout growth, with a fair show of purple colour, is everywhere appreciated, and is the easiest to produce, because the most natural.
There is, however, an interesting point in connection with the production of green Asparagus, and it is that if wintry weather prevails when the heads are rising (as unfortunately is often the case) the tender green tops may be melted by frost and become worthless, or may be rendered so tough as to place the quality below that of blanched Asparagus; for the blanching is also a protective process, and quickly grown white Asparagus is often more tender and tasty than that which is green, but has been grown slowly. As the season advances and the heads rise rapidly the green Asparagus acquires its proper flavour and tenderness, and thus practical considerations should more or less influence final decisions on matters of taste. The business of the cultivator is to produce the kind of growth that is required, whether white or green, or of a quality intermediate between the two. This is easily done, making allowance for conditions. When green Asparagus is alone in demand, the cultivator may be advised to have in readiness, as the heads are making their first show, a sufficient supply of some rough and cheap protecting material, such as grass and coarse weeds, cut with a sickle from odd corners of the shrubbery and meadow land, or clean hay and straw perfectly free from mildew; but for obvious reasons stable litter should not be used. A very light sprinkling of material over an Asparagus bed that is making a first show of produce will ward off the morning frosts, and amply compensate for the little trouble in saving many tender green sticks that the frosts would melt to a jelly and render worthless. After the second or third week in May the litter may be removed if needful; but if appearances are of secondary importance, it may be left to shrink away on the spot.
Cutting.—Asparagus as supplied by market growers is needlessly long in the stem. The bundles have an imposing appearance, no doubt, but the useless length adds nothing to the comfort of those at table, and is a wasteful tax on the energy of the plant. For home consumption it will generally suffice if the white portion is about four inches long, and this determines the depth at which the sticks should be cut. Here it may be useful to remark that deeply buried roots do not thrive so well as those which are nearer the surface, nor do they produce such early crops. The sticks are usually cut by thrusting down a stiff narrow-pointed knife, or specially made saw, close to each shoot; and it is necessary to do this with judgment, or adjacent shoots, which are not sufficiently advanced to reveal their presence by lifting the soil, may be damaged. To avoid this risk of injury by the knife it is possible from some beds to obtain the sticks without the aid of any implement by a twist and pull combined, but the process needs a dexterous hand and is impracticable in tenacious soils. The sticks of a handsome sample will be white four or five inches of their length; the tops close, plump, of a purplish-green colour, and the colour extending two or at most three inches down the stems. Both size and degree of colouring are, however, so entirely questions of taste that no definite rule can be stated. It is more to the purpose to say that, if liberally grown, the plant may be cut from in the third year; and that cutting should cease about the middle of June, or early in July, according to the district. For the good of the plant the sooner cutting ceases the better, as the next year’s buds have to be formed in the roots by the aid of the top-growth of the current season.
Weeding and Staking.—Two other points relating to the general management are worthy of attention. Some crops get on fairly well when neglected and crowded with weeds. Not so with Asparagus. The plant appears to have been designed to enjoy life in solitude, being unfit for competition; and if weeds make way in an Asparagus bed, the cultivator will pay a heavy penalty for his neglect of duty. The limitation of the beds to a width of three feet, therefore, is of consequence, because it facilitates weeding without putting a foot on them. The other point arises out of the necessity of affording support to the frail plant in places where it may happen to be exposed to wind. When Asparagus in high summer is rudely shaken, the stems snap off at the base, and the roots lose the service of the top-growth in maturing buds for the next season. To prevent this injury is easy enough, but the precautions must be adopted in good time. A free use of light, feathery stakes, such as are employed for the support of Peas, thrust in firmly all over the bed, will insure all needful support when gales are blowing. In the absence of pea-sticks, stout stakes, placed at suitable distances and connected with lengths of thick tarred twine, will answer equally well. In sheltered gardens the protection of the young growth with litter, and of the mature growth with stakes, need not be resorted to, but in exposed situations these precautions should not be neglected.
Manuring Permanent Beds.—The management of Asparagus includes a careful clean-up of the beds in autumn. The plants should not be cut down until they change colour; then all the top-growth may be cleared away and the surface raked clean. Give the beds a liberal dressing of half-decayed manure, and carefully touch up the sides to make them neat and tidy. It is usual at the same time to dig and manure the alleys, but this practice we object to in toto, because it tends directly to the production of lean sticks where fat ones are possible; for the roots run freely in the alleys, and to dig is to destroy them. In the spring clear the beds of the autumn dressing by raking any remnant of manure into the alleys, and the beds and the alleys should then be carefully pricked over with a fork two or three inches deep only, and with great care not to wound any roots.
The application of salt requires judgment. For a time it renders the bed cold, and when followed by snow the two combine to make a freezing mixture which arrests the growth of established plants. On a newly made bed salt is unnecessary, and may prove destructive to the roots. The proper time for applying salt must be determined by the district and the character of the season; but in no case should the mineral be used until active growth has commenced, although it is not needful to wait until the growth is visible above the surface. In the southern counties a suitable opportunity may generally be found from the beginning to the middle of April. Second and third dressings may follow at intervals of three weeks, which not only stimulate the roots but keep down weeds.