White Bunching Onion
Sowing
Since most onions take a few months to mature from seed, gardeners with a short growing season may want to start their green onion seed indoors. Plant the seeds 1/4″ deep in a flat 2-3 months before the last frost date; keep the soil moist and at room temperature. When the tops begin to flop over, cut them off to 3″ to focus the growing on the roots. Four weeks before the last frost or when the soil reaches at least 50 degrees F, transplant the seedlings 3″ apart in rows 12″ apart. For direct sowing, sow three seeds per inch 1/4″ deep in light, rich soil and full sun. Thin the seedlings 3″ apart. Thinned onions can be transplanted or used for fresh eating. For companion planting benefits, plant onions with members of the cabbage family, lettuce, or tomatoes; avoid planting onions with peas or beans.
Growing
Onions need moisture especially in their first several weeks of growth, and they cannot fight against weeds; mulching onions can help with both moisture and weed control. Evergreen White Bunching onions tolerate cold and light frost, since they are the most cold hardy bunching onion available. Green onion seeds are slow to bolt and resistant to PR, thrips and smut.
Harvesting
Bunching onions can be harvested any time after 60 days; the longer they remain in the ground, the stronger the taste will be. If protected sufficiently from the cold, the green onion plants will overwinter for spring bunching. This variety of onion can be used for both green onions and scallions, but does not store well long term.
Seed Saving
Onions need to overwinter before producing seed. In warmer locations, simply apply a thick layer of mulch and remove it in the early spring. In areas with very cold winters, pull up the onions and cut off half the stem; store them at 32-40 degrees F in a dry place until spring, when they can be replanted. Before planting, cut an X in the top of the onion to allow the stalk to emerge. The green onion plants will flower and go to seed. Remove the seed heads when the seeds become visible, taking care not to shatter the heads and lose the seed. Spread the heads out in a dry place with good ventilation, and let them dry for several weeks. Thresh out the green onion seeds and store them in a cool, dry place for up to 2 years.
Common Pests
Cutworms: They are among the most inefficient eaters in the insect world. A few bites and they are done, which means a single cutworm can kill a dozen plants in a few days time. Fortunately this damage is easily preventable, when you transplant the seedlings, encircle them with a protective collar made from a paper cup with the bottom punched out. Another method is to stick a toothpick or twig down the side of the plant stem. When the cutworm attempts to encircle the stem to girdle it, the tough wood gets in the way.
Onion Maggots: These little creatures love cool, damp weather. Like many other flies, they overwinter as tiny pupae and emerge in spring. Eggs laid around onion plants hatch into wormy little maggots that devour all the underground parts of the onion. When gardening bulb onions from seed, keep the seedbed covered with floating row covers. Transplant the seedlings to soil where onions have never been grown before and dust the furrow lightly with fresh wood ash.
