As soon as possible after the crop is visible the ground between should be delicately chopped over with the hoe to check the weeds that will then be rising. Immediately the rows are defined a first thinning should be made with a small hoe, care being taken to leave a good plant on the ground. The next thinning will produce young Onions for saladings, and this kind of thinning may be continued by removing plants equally all over the bed to insure an even crop, the final distance for bulbing being about six inches. Keep the hoe at work, for if weeds are allowed to make way, the crop will be seriously injured. When Onions are doing well they lift themselves up and sit on the earth, needing light and air upon their bulbs to the very axis whence the roots diverge. If weeds spread amongst them the bulbs are robbed of air and light, and their keeping properties are impaired. But in the use of the hoe it is important not to loosen the ground or to draw any earth towards the bulbs. When all the thinning has been done, and the weeds are kept down, it will perhaps be observed that in places there are clusters of bulbs fighting for a place and rising out of the ground together as though enjoying the conflict. With almost any other kind of plant this crowding would bode mischief, but with Onions it is not so. Bulbs that grow in crowds and rise out of the ground will never be so large as those that have plenty of room, but they will be of excellent quality, and will keep better than any that have had ample space for high development. It is almost a pity to touch these accidental clusters, for the removal of a portion will perhaps loosen the ground, and so spoil the character of those that are left. Really fine Onions are rarely produced in loose ground, hence the necessity for care in the use of the hoe. Watering is not often needed, and we may go so far as to say that, in a general way, it is objectionable. But a long drought on light land may put the crop in jeopardy, unless watering is resorted to, in which case weak manure water will be beneficial. Still, watering must be discontinued in good time, or it will prevent the ripening of the bulbs, and if a sign is wanted the growth will afford it, for from the time the bulbs have attained to a reasonable size the water will do more harm than good.
The harvesting of the crop requires as much care as the growing of it. If all goes well, the bulbs will ripen naturally, and being drawn and dried on the ground for a few days with their roots looking southward, may be gathered up and topped and tailed or bunched as may be most convenient. But there may be a little hesitation of the plant in finishing growth, the result, perhaps, of cool moist weather, when dry hot weather would be better. In this case the growth may be checked by passing a rod (as the handle of a rake for example) over the bed to bend down the tops. After this the tops will turn yellow, and the necks will shrink, and advantage must be taken of fine weather to draw the Onions and lay them out to dry. A gravel path or a dry shed fully open to the sun will ripen them more completely than the bed on which they have been grown; but large breadths of Onions must be ripened where they grew, and experience teaches when they may be drawn with safety.
As to keeping Onions, any dry, cool, airy place will answer. But if a difficulty arises there is an easy way out of it, for Onions may be hung in bunches on an open wall under the shelter of the eaves of any building, and thus the outsides of barns and stables and cottages may be converted into Onion stores, leaving the inside free for things that are less able to take care of themselves. During severe frost they must be taken down and piled up anywhere in a safe place, but may be put on their hooks again when the weather softens, for a slight frost will not harm them in the least, and the wall will keep them comparatively warm and dry. When the best part of the crop has been bunched or roped, the remainder may be thrown into a heap in a cool dry shed, and a few mats put over them will prevent sprouting for at least three months. But damp will start them into growth, and the only way to save them then is to top and tail them again, and store as dry as possible in shallow baskets or boxes.
To grow large Onions the principles already explained must be carried into practice in a more intense degree. It will be necessary to devote extreme care to the preparation of the ground, and to give the plants more time to mature; much greater space must also be allowed than is usual for an ordinary crop. A good open position is imperative, and where the soil is sufficiently deep, trenching is desirable. Shallow soil ought to be thoroughly dug down to the last inch, and it will be an advantage to break up the subsoil by pickaxe and fork. Cover the subsoil with a thick layer of rotten manure before restoring the top soil. For light land farmyard manure is excellent, but stable manure is preferable for stiff cold soil. The usual time for trenching is October or November, leaving the surface rough for disintegration during winter. Nothing more need be done until the following March. Early in that month break the soil down to a fine tilth and make it quite firm by treading, or by rolling. Then broadcast over the plot a liberal dressing of ground lime and soot, using about three pounds of each per pole. Rake both in and leave the bed until the time arrives for planting out: this will depend on the weather.
Those who are accustomed to exhibit Onions at horticultural shows almost invariably sow very early in the year under glass and in due time transplant either from seed-pans or boxes. Of the two, properly prepared boxes are usually found most convenient. The dimensions are optional, but boxes about two feet long, one foot wide, and five inches deep answer admirably. Several holes are perforated in the bottom to insure efficient drainage. In every box place a thick layer of rotten manure and then fill with thoroughly rich soil firmly pressed down, leaving the surface quite smooth. One of the most successful growers sows seed in rather small boxes early in January, and about the middle of February the young Onions are pricked into boxes of the size we have named. Only the finest and most promising seedlings are used. When transferred, each Onion is allowed a space of three inches. The boxes are kept in a greenhouse, as near the glass as possible, in a temperature of about 50°. After sowing, very little water is given; but when transplanted, finish with a sprinkling from a fine rose. Every morning the plants will require spraying, but this must never be done at night or damping off may follow. All through their time in the greenhouse it is important to keep the boxes near the glass. Towards the end of March remove to cold frames, keeping the lights rather close for a few days, but gradually giving more air until the lights can be taken off for a short time daily.
In the south, about the middle of April is generally a suitable time for transplanting to open beds, but in the event of a cold east wind prevailing a brief delay is advisable and it is always an advantage to plant out on a dull day or in showery weather. Space the rows twelve to eighteen inches apart, and allow about fifteen inches between plants in the rows. In the actual work of transplanting take care to insert only the fibrous roots in the soil. To bury any portion of the stem results in thickened necks. Finish with a dusting of soot over the entire bed, including the Onions, and then well spray from a fine rose to settle the soil around the roots. Until the plants are established continue the spraying daily. After the middle of May renew the dusting of the bed with soot and repeat at fortnightly intervals. About the 20th of June feeding the Onions must commence. Peruvian guano and nitrate of soda are both excellent, but these powerful artificials need using with discretion, or the crop may be scorched instead of stimulated. It is often safer to employ them in liquid form than dry, and ten ounces of either, dissolved in ten gallons of water, will suffice for thirty square yards. Use the two articles alternately at intervals of ten days and cease at the end of July. If continued longer, some of the finest bulbs will split. The use of soot can, however, be regularly maintained. Should bulbs be required for autumn exhibition carefully lift them a week or ten days in advance of the show date. This has the effect of making the bulbs firm and reducing the size of the necks.
Supposing an attack of mildew to occur, a dusting of flowers of sulphur will prove effective if applied immediately the disease appears. Sulphide of potassium, one ounce to a gallon of water, is also a reliable remedy.
July and August Sowing.—During these months seed of the quick-growing types of Onion may be sown for producing an abundant supply of salading and small bulbs during the autumn and onwards. It is important to thin the plants early in order that those left standing in the rows may have every opportunity of developing rapidly.
Autumn-sown Onions, intended for use in the following summer, may also be sown in the same way as advised for spring sowing. The time of sowing is important, as the plants should be forward enough before winter to be useful, but not so forward as to be in danger of injury from severe frost. On well-drained ground all the sorts are hardy, and the finest types, which are so much prized as household and market Onions, may be sown in autumn as safely as any others. It may be well in most places to sow a small plot: in the latter part of July, and to make a large sowing of the best keeping sorts about the middle of August—say, for the far north the first of the month, and for the far south the very last day. Thin the plants in the rows and transplant the thinnings, if required, as soon as weather permits in February. In places where spring-sown Onions do not ripen in good time in consequence of cold wet weather, autumn sowing may prove advantageous, as the ripening will take place when the summer is at its best, and the crop may be taken off before the season breaks down.
Pickling Onions may be obtained by sowing any of the white or straw-coloured varieties that are grown for keeping, but the large sorts are quite unfit; the best are the Queen and Paris Silver-skin, as they are very white when pickled and are moderately mild in flavour. A piece of poor dry ground should be selected and made fine on the surface. Sow in the month of April thickly, but evenly, cover lightly, and roll or tread to give a firm seed-bed, and make a good finish. Be careful to keep down weeds, and do not thin the crop at all. If sown very shallow the bulbs will be round: if sown an inch deep they will be oval or pear-shaped.