174 THE BOOK OF VEGETABLES 



for the land, as the seeds germinate very slowly, and 

 the best of surface tillage, as the young plants are 

 easily killed by weeds. The old style of onion -bed is 

 I now universally discarded 



f or cu it ure in straight 

 rows, and in Onion cul- 

 ture more than in many 

 others the wheel-hoe and 

 mechanical planter are 



Fig. 81. A modern Onion field. Ex- ., , 



cept for early weeding it can be of great USC. But hand- 

 cultivated with wheel-hoes, weeding is necessary, 



especially when the plants are young, and thinning also 

 requires hand work. The Onion is very hardy to frost, 

 and is somewhat tender to heat; therefore, the seed is 

 always sown as early in the spring as possible, in order 

 to have the plants well growing by midsummer. In mild 

 climates, for the same purpose, seed is sown in the fall. 

 From spring-sown seed the fall crop is gathered; for 

 earlier Onions "sets,"" "tops," or "potato onions" are set 

 out. These are all bulbs grown by one method or an- 

 other, "sets" being bulbs arrested in their growth and 

 stored for spring use, "potato onions" or "multipliers" 

 being compound Onions of which the parts or bulbels 

 are planted separately. Each bulbel will produce a com- 

 pound bulb. "Tops" or bulblets are described above. 

 There are several varieties of top-onions and potato- 

 onions, while sets may be grown, as described below, 

 from the seed of any variety, though the results vary. 



