64 THE SEED-GROWER. 
however, are more productive, bearing larger seed- 
stems than do plants from smaller bulbs. But it is 
customary with many who grow onion sets extensively, 
to raise their own seed from small bulbs not under the 
size of a walnut, sorted by themselves from the larger 
onions produced in a crop of sets. Seed produced from 
such bulbs is not inferior to that from full-grown bulbs. 
Bulbs should be set out in drills, six inches deep, six 
inches apart, in rows three feet apart. Fifty sacks of 
full-grown bulbs are usually planted to the acre. Cul- 
tivate the crop twice or more. 
In the Northern States, planting of bulbs is done late 
in summer so as to secure a good growth before winter. 
The onion is hardy and withstands the winter without 
protection, and seed produced from fall planting will 
mature earlier than that from spring-planted bulbs. 
In California, planting of bulbs is done from late in 
autumn until February Ist, seed being harvested in 
October. In that climate the bulbs which are harvested 
in autumn are simply stored in sacks, and generally 
kept piled out of doors until wanted for planting. 
When seed-heads turn yellow, and begin to burst, 
they may be cut. They are placed on cloths and left 
exposed to the sun and air to dry for a day or longer, 
according to climate. They are then taken to the barn 
or shed, spread thinly, and allowed to become thor- 
oughly dry before threshing. 
Threshing is done in a threshing machine; or may be 
done with a flail or a roller, on a cloth laid on the floor. 
Seed is then run once or twice through the fan-mill or 
seed-cleaner. After which it is given a washing in a 
tank or in a tub of water, to remove the light seeds and 
remaining portions of pod. For this operation a clear, 
dry day is chosen. In the washing process, the whole 
