Onions: summer-sown bulbingunder cover will usually produce heavier, earlier, and more fully ripened crops than unprotected bulbs. Spacings can be 22 cm (9”) between rows for all crops, bulb onions being thinned to stand 15 cm (6”) apart. Salad onions are not, as a rule, thinned. In addition to the late summer-sown crop, sowings of bulb onions can be made under cloches in late winter and thinned, or sown in a greenhouse in mid- to late winter and transplanted in mid-spring. Remember, however, that transplanted onions are more likely to bolt. Salad onions can be sown in late summer and early autumn for spring and summer use; or in late winter and early spring for summer and autumn pulling.