Plant Walla Walla Sweet Onions as soon as the ground can be worked. Enrich the soil with a vegetable fertilizer, such as Lilly Miller® Morcrop. Should the weather be unfavorable when plants are received, and the plants are wet, loosen the bundles and spread them so the tips may dry. If the plants are wilted, just stand them on ends in a growing position in a cool, dry place. When the weather becomes fair, put them out at once. Trim the roots of onion plants and cut off shaggy ends and tops to give a quicker start. Plant with base 2 inches deep. Set plants 4 to 6 inches apart in rows 18 inches apart. The young plants thinned out make delicious green onions. Harvest matured plants when approximately two-thirds of plant tops have fallen over. Let dry on the ground for a few days, or if it is raining, put them on a garage, barn, or other floor indoors. Then, cut off tops one inch from bulb and store in ventilated trays in a cool place. Make sure the storage space is dry — dampness causes onions to sprout.