 tip of the bulb should be just poking out of the soil.
When selecting onion varieties, choose ones that are appropriate for your area. Onions bulb in response to the number of hours of sunlight they receive. In the North, the amount of daily sunshine varies dramatically during the course of the year, with many hours of sunshine in the Summer and relatively few during Winter. In the deep South, day lengths are much more consistent during the course of the year and summer days are not as long as they are in the North. So folks in the Southern U.S. should buy "short-day" varieties (bulbs start to form when there are 10-12 hours of sunshine) and folks in the Northern U.S. should buy "long-day" varieties (bulbs start to form when there are 14-16 hours of sunshine). Intermediate-day onions fall between these extremes (bulbs start to form at 12-14 hours of sunshine) . See the below map of the U.S. to determine which type of onion is right for you or check out the Gaisma web site which lists hours of sunshine by month for the U.S. and other countries.
Garlic and Onions planted in the Fall should be ready for harvest in June or July. Timing really depends on variety and your location. The best way to tell when to harvest is to observe for your plants for clues that it is time to harvest.
- Harvest onions when the leaves lose their color and fall over. Once this occurs, leave the onions in the ground for another 10 days to allow the onions to reach full maturity. If possible, harvest onions on a sunny day since the bulbs will contain less moisture and will store better. After removing from the ground, cure in the sun for 1 day to kill the root system of the bulb. This also improves the storage life of your onions. Then store in a cool, dark and dry place.
- Garlic is a little trickier. Wait till most of the leaves die back and turn brown, but before all of the leaves have toppled over as with onions. I recommend testing by harvesting a bulb or two and checking to see if they are mature. The bulb should be the appropriate size for the variety you are growing and you should be able to feel the individual cloves under the outer skin of the bulb. If so, harvest the garlic and then cure in a dry place for two to four weeks. Longer for very large bulbs. When storing garlic, I don't trim the leaves or the roots. I believe this helps preserve them, but there are more opinions on the best way to cure garlic than there are stars in the sky.
Harvesting Garlic, from the Tacuinum Sanitatus, 1500's.
Onion and Garlic Varieties
There are many varieties of onions and garlic from which to choose. The varieties differ in terms of their taste characteristics (strong/hot or mild), storage capabilities (short and long storage) and growth habit. (early, mid and late season for garlic or short-day and long-day for onions)
When choosing an onion for your garden, be careful to select one that will work in your location; onion plants create bulbs based on the number of hours of sunlight they receive and are sold as "long-day," "short-day," and "intermediate day" varieties. Northern gardeners should purchase long-day onions and gardeners in the South should opt for short-day onions. Onions also differ dramatically in terms of their size, from tiny "pearl" onions up to the huge Ailsa Craig that can tip the scales at up to 6 pounds. Check out the varieties offered by mail order companies to find onions and garlic that meet your tastes and geographic requirements. Here are some varieties you might consider:
- Purple Glazer Garlic - a mild tasting, easy to peel, mid-season variety.
- Music Garlic - a moderately hot, mid season variety with high yields.
- Chesnok Red Garlic - a strong, late season garlic that is good for cooking.
- Ontario Purple Trillium garlic - a very strong and very early maturing garlic.
- Borrettana Cipollini onion - a small (2 inch), flat, yellow, long-day onion that is a good storage.
- Red Wethersfield onion - a red, long-day onion thats shaped like a flattened globe. It's an heirloom variety from Wethersfield, Connecticut.
- White Berm