I have heard it remarked that the best Onion grower is the man who is the proud possessor of the largest feet, which is a delicate way of hinting that the secret of successful Onion culture is firm soil. There is a great deal in it, to be sure, but it does not mean everything in these days of high culture, and however richly endowed a person may be in the way of pedal extremities, he finds a few other things demanding attention.
The Onion, Allium cepa, is an old vegetable, -and doubtless the gardeners of past days considered that there was nothing left to learn about it. They would be surprised, perhaps, if they could revisit these glimpses of the moon and see bulbs of 3 lb. weight produced the same year as sown.
There are several important items in the production of large Onions, which I will tabulate:-
(1) Choice of variety. I put this first because it is the most vital point. However thorough the culture may be, it is impossible to produce large bulbs if naturally small sorts like James's Keeping and Bedfordshire Champion are selected. I consider Ailsa Craig to be the best of all. Others capable of being grown to a large size are Anglo-Spanish, Carters' Record, Cocoa Nut, Cranston's Excelsior. Lord Keeper, and Ne Plus Ultra. All of these will give bulbs 2 lb. to 3 lb. in weight. Somewhat smaller, say 1 lb. to 1 3/4 lb., are Improved Wroxton, Suttons' Al, and Veitchs' Maincrop.
(2) Early sowing, under glass. The seed should be sown between the middle of January and the middle of February, and the box placed on a greenhouse shelf. Heat is not essential, although it brings the plants along rapidly. A cold frame will do in an emergency, but the plants thus raised are hardly likely to become as large as those raised in a heated house.
(3) Deep boxes. It is a great mistake to use a box less than 4 inches deep. In shallow boxes the roots become matted on the bottom, and many are torn away when transplanting.
(4) Thin sowing. If the seeds are sown thickly the young plants become crowded, and the grower is tempted to prick them off too soon. They ought not to be pricked out until they are at least 3 inches high, because at an earlier stage the roots are very brittle.
(5) Rich, deeply trenched soil. This, and manuring, have been dealt with in a previous chapter.
(6) Thorough harvesting. The bulbs must have a good roasting or they will not keep. I find it well to bend the tops over in August, but to leave the plants on the ground till mid-September, loosening them on various occasions so as to break the roots by degrees. Afterwards lay them in the sun for a fortnight, taking them under cover on wet days and at night.
Fig. 58. How To Grow Large Onions.
A, seed sown in fine soil in a glass-covered box.
B, plants ready to transplant into another box, D.
C, a plant ready for putting out. bulbs.
E, where conveniences exist the plants may be grown on in pots before being planted out to yield very large.
There is nothing gained by planting the seedlings very early in spring. In cold districts the third week in April is soon enough. The plants should then be as thick in the stem as a quill pen. They may be planted 1 foot apart in rows 18 inches asunder. The soil must be firm, and only enough should be loosened at planting to cover the roots.
If the soil is well tilled and fed, neither water nor liquid manure will be required after the plants start growing. My biggest bulbs have been produced when no feeding has been attempted. All the summer culture required is to keep down weeds.
If very large bulbs are wanted from a summer sowing, choose the Lemon Rocca, and sow at the middle of August. I have seen 2 1/2 lb. bulbs of this variety.
Small Onions are too useful in the kitchen ever to be ousted by the big sorts, and they must not be neglected. The two named above, also Brown Globe, Danvers' Yellow, Deptford, and White Spanish are old favourites for spring sowing 1 inch deep in rows 1 foot apart, to be thinned lightly. Generally speaking they keep better than the large bulbs if dry - damp soon spoils them.
Pickling Onions are not perhaps grown so extensively now as they used to be, many people preferring to pickle Shallots. However, we must not forget that there are pickling sorts to be had, or that the variety Queen, if grown thickly in very poor soil, makes a splendid pickier.
Fig. 59. A 2 1/2 LB. Bulb Of Cocoanut Onion; The Small Variety On The Right Is Brown Globe.
Potato or underground Onions are valuable, being productive, mild, and usually free from insect attacks. The bulbs may be planted 9 inches apart in rows 1 foot or more asunder, in deep, rich soil, in February if possible.
Tree Onions are hardly worth growing when we have so many more useful members of the family with which to utilise our space.