Vegetable Gardening (35 page)
‘Yellow Sweet Sandwich':
This hybrid variety actually gets sweeter in storage and comes in a white-skinned version called ‘White Sweet Sandwich'. Both versions are available as plants. The variety matures 100 days after seeding.
‘Walla Walla Sweet':
This sweet, hybrid variety has light yellow flesh and good cold tolerance. It's available as a plant and is popular in the Northwest. It matures 115 days after seeding.
‘Yellow Stuttgarter':
This pungent, standard, open-pollinated storage variety often is sold as a set. It matures in about 90 days from a set and 120 days after seeding.
Looking at scallions and perennial onions
You may have run across some other onion types in restaurants or produce markets. For example,
scallions
(also called bunching onions, spring onions, or green onions) are picked for their delicate, juicy, green tops before they form bulbs. Scallions take up less space in your garden than regular onions because you can plant them closer together, and they can give you a quick crop when planted in spring or fall. Growing scallions is a good way for novice onion growers to start.
Any onion variety grown from a seed can be harvested as a scallion, but here a few varieties that are especially widely adapted as scallions:
‘Evergreen Hardy White' (
Allium fistulosum
):
This hardy, white-stalked variety is a great one for cold climates (USDA zone 5), and it can overwinter if protected and used as a perennial. It matures 65 days after seeding.
‘Red Beard' (
Allium fistulosum
):
This tender variety has unique coloring: a red stem with a white tip and green leaves. It matures 45 days after seeding.
‘White Spear':
This heat-resistant scallion features blue-green leaves and thick white stems. Good for warm climates. It matures 65 days after seeding.
Multiplier,
or perennial, onions come back year after year and reproduce easily. Here are the two main types:
Egyptian top-set onions (also known as walking or tree onions):
These onions reproduce by forming clusters of onion sets on the tips of their growing stalks, as shown in Figure 6-1. As the weight pulls the stalks down, the clusters root wherever they land, making the onions look like they're walking slowly across your garden. During the winter months, Egyptian top-set onions primarily are eaten as scallions, but the top-sets make good, small, sweet onions when you pick them in summer. They're also very cold hardy.
Potato onions:
These onions form a main onion in summer from a fall planting. They're hardy to USDA zone 4 and produce many smaller sets that you can replant after summer harvest to produce more onions the following year.
What a difference a day makes!
The long-day, short-day, intermediate-day onion issue can get confusing. Short-day onions form bulbs when they receive 11 to 12 hours of daylight, while long-day onions form with 14 to 16 hours of daylight. Generally, gardeners north of 35 degree latitude (a line running from northern North Carolina through Oklahoma and Arizona to central California) grow long-day onions because their summer days are long enough to initiate bulb formation. Gardeners south of that line grow short-day onions because they're closer to the equator and their day lengths are pretty steady at 12 hours. Gardeners in the South also have the luxury of planting short-day onions in fall, overwintering them (because of their mild winters), and harvesting in late spring.
Northern gardeners need to plant long-day onions in spring for a summer harvest. If you were to plant long-day onions, such as the ‘Copra' variety, in the South, they'd never receive enough daylight hours to bulb up. Likewise, short-day onions, such as the famous ‘Vidalia' onions, grown in spring in the North, would bulb up quickly while the plants were small because they'd receive the necessary 12 hours of daylight early in the season. The end result would be small bulbs.
Modern plant breeders have made this whole task a bit easier by introducing intermediate-day varieties that aren't as dependent on certain amounts of daylight hours to form bulbs. These varieties like intermediate lengths of daylight (12 to 14 hours) and grow best in hardiness zones 5 through 8 (see the appendix for more about zones).
