ONIONS (Allium cepa)
To grow goodis the ambition of every gardener. It has long been the common theory that onions will not grow in virgin , but only in soil that has been well cultivated for a number of years, and there is some reason for this belief. As far as possible an open, sunny position shoukl be chosen and the soil should be deeply dug. Well-decayed farmyard manure should be worked in at the same time to a considerable depth.
Bastard trenching is considered sufficient by most growers, but some advise trenching the soil so that the lower layer is brought to the surface. The advisability of this depends largely on the condition of the soil. If it has been under cultivation for many years and the subsoil is in good condition, it may be brought to the surface, but if the surface soil is rather thin, and clay gravel, or chalk forms the subsoil, it would be very inadvisable to bring up the subsoil.
For ordinary household use, onions can be sown outdoors about the beginning of March. To prepare the bed forit should be trodden and raked, and trodden and raked several times, so that though the lower soil is fairly settled, the top is light and friable. A dressing of wood ashes, soot and lime, dusted freely over the bed, together with sharp sand if the soil is inclined to be heavy, will assist in making the texture what it should be. All this material can be forked into the top 6 in. of soil before the treading and raking take place.
Seed will be sown in shallow, 1 in. drills about 12 in. apart. It is sown thinly along the drill, and covered by walking along the line pushing the soil over the seed with the foot and pressing it firmly. This ensures that the seed is in contact with the soil and is well covered. The final work of sowing consists in raking the seed bed in the same direction as the drills run. This somewhat loosens the surface soil, and gives a tidy appearance to the plot.
As soon as the onions show through the ground, looking like little tiny green wires bent over at the top, dust the bed with fresh soot, and give a similar dusting along the rows at frequent intervals all through the growing season. This serves a double purpose. It darkens the colour of the soil, and makes the bed relatively warmer, and it helps to keep away the Onion Fly, which is the worst pest of the onion in this country.
Any good fertilizer can be given on the onion bed. This crop responds very rapidly to the use of artificials. A good treatment is three parts of kainit, five parts of superphosphate of lime, mixed and applied in spring at the rate of four ounces per square yard, followed by small applications of nitrate of soda dusted, or watered along the rows at frequent intervals during the summer. Liquid fertilizer must of course, only be applied after the soil is already wet with rain or water.
When growth has nearly finished, bend the tops of the onions over to encourage the ripening of the bulbs, and about a fortnight later lift them and lay them on the ground to dry. They can then be taken up and stored in an airy frost-proof shed, either roped together or laid in trays or boxes where they can be turned over from time to time.
For exhibition Onions, a bed should be selected in the autumn and trenched if the soil is light, or trenched in spring if the soil is heavy. Soot, lime, etc., should be added as already described. About in. should be allowed between each row and the plants thinned to allow about in. between each. Overcrowding is extremely harmful. Seed is sown under glass in the middle of December, after Christmas, or the end of January.
For the seed boxes, soil from an old hotbed, with sharp grit, leaf-mould and fibrous loam is passed through a ¾ in. mesh sieve. It is filled in to about 1 in. from the top of the box and made firm. The seeds are sown carefully about 1 in. apart all over the box. When theare about 1-½ in. high, they are pricked out into other boxes, in soil enriched by adding bone-meal. All this time the seedlings are kept near the glass in greenhouse in a temperature ranging from 55 to 60°. Keep the soil in the boxes open, by occasionally stirring it with the point of a stick, and as soon as possible harden off the plants, first by transfer to a cold frame, and then by removing the lights of the frame whenever the weather is suitable.
Transplanting the onions to the open ground is a delicate operation, which is of importance to the future of the plants. As large a ball of soil as possible should be retained with each root, and the plants should be set firmly about in. apart. The usual time foris about the middle of April. During the season, the hoe should be kept going and the foliage occasionally damped with a syringe and afterwards dusted with soot. Frequent application of a good fertilizer is advisable, and liquid manure made from animal droppings is also useful.
For exhibition purposes there is still no better onion than “Ailsa Craig.” It is best to ripen off the Show onions under glass after they have been raised from the ground, letting them lie in the open only in the middle of the day, and returning them under cover at night. The rough outside skins must be removed, and the one left to ripen should be smooth and clean. The necks of the onions should be tied down and made to look as small as possible.
The practice of sowing onions in the autumn for the following season’s crop has much to commend it in gardens where the Onion Fly is particularly troublesome. Seeds can be sown in August and allowed to remain in the seed bed until spring, when they are lifted and planted out in. apart each way. Such onions are usually free from attacks of the Onion Fly, which prefers the tender, newly-sown onions on which to lay its eggs. Another way to avoid the fly is to use onion sets, ie. small bulbs, which are planted like. The only trouble with these is that they show a greater tendency than seedlings to go to seed.
These are grown in exactly the same way as ordinary onions, but are sown towards the end of April in fairly poor soil.
Good onions for general purposes are as follows: “Ailsa Craig,” “Bedford Champion,” “Cranston’s Excelsior” and “Silver Queen” (for pickling).