CULTURAL DIRECTIONS 385 



Sandy loams, when properly enriched with humus and 

 plant food, furnish excellent conditions for onions. They 

 are easily worked and produce solid, heavy bulbs of 

 superior keeping quality. 



Clay soils should be avoided. They become too hard 

 and compact for best results. Clay and alluvial loams, 

 when properly handled, yield profitable crops, but the 

 supply of humus must be liberal to prevent serious bak- 

 ing.' Incrustation is especially damaging when it occurs 

 before the plants are up or large enough to permit thor- 

 ough tillage. 



532. Seed. — Inferior seed is the source of heavy and 

 frequent losses in onion culture. Onion seed must be 

 fresh, never more than a year old and produced from 

 bulbs of a superior character. Someseed firms have es- 

 tablished reputations for selling high-grade seed of this 

 vegetable, and growers should exercise extreme care in 

 ascertaining the best sources of supply. 



While it is less difficult at present to procure good seed 

 than formerly, a large number of gardeners and onion 

 specialists raise their own seed. The bulbs are best 

 selected at harvest. They should be of the desired size 

 and form. A short neck is considered an advantage. 

 Uniformity in all of the essential characteristics is ex- 

 ceedingly important in choosing bulbs for seed pur- 

 poses. Seed bulbs should be stored as directed in this 

 chapter (541) and planted as early as possible in the 

 spring. (Some growers prefer fall planting.) The 

 ground should be only moderately fertile, especially in 

 nitrogen. Furrows are made 4 or 5 inches deep and 

 14 to 30 inches apart, depending upon the method of 

 "cultivation. After placing the bulbs about 6 inches 

 apart in the bottom of the furrow, they are covered with 

 a hoe or a small plow. The long, slender seed stalks 

 should have some support, which may be provided in 

 two ways: (i) By ridging with soil to the height of 7 



