2 The onion, known botanically as Allium cepa, is the most widely cultivated species of the genus Allium. Onions should be planted in early spring. They do best when temperatures are cool once they start to grow, and warm when they begin to mature. Early planting gives the onions time to develop tops and store energy for the bulbs.
4 When planting onions, select a location with full sun where they won't be shaded by other trees or plants. The best soil for onions is well-drained, loose and rich in nitrogen. Onions are heavy feeders, and require constant nourishment if they are to produce big bulbs.
5 We wanted the onion plant rows to look tidy and straight. In order to do this, my gardener, Wilmer, used a long bamboo stick that extended from one end of the garden bed to the other. He laid the bamboo stick right on top of the bed and lined up the onion plants next to it.
6 The onion plants were carefully pulled apart and planted at least four-inches away from each other. Using the bamboo to line the plants properly made the best use of the beds, allowing four rows of onions in each.
7 Onions come in three general colors: red/purple, yellow and white. Although the white onion makes up only five-percent of the American onion harvest, it is the all-purpose onion. It has pure white skin and sweet, mild white flesh. White onions are commonly used in sauces, pasta salads, and in Mexican and Southwestern cuisines.
8 Onions are also categorized in two growing types: long-day and short-day. Long-day onions begin sprouting in late spring to summer when days are between 14 and 16 hours long. Short-day onions begin sprouting when days are between 10 and 12 hours in length - winter and early spring.
9 When planting, grasp the onion plant at the top with the root end down and push it into well-prepared soil. The plant should be dropped about one-inch deep. Onions will grow quite large if planted properly and given enough space.
10 Roots grow out of the bottom of the onion bulb, and tend to only be about 12-18 inches deep in the soil. They are biennial plants, which means they will live for two years before flowering and then die. After the first growing season, mature bulbs can be left in the ground or dug up and replanted.
11 Red onions, sometimes called purple onions, have reddish-purple skin and white flesh, tinged with red. These onions are medium to large in size and have a mild to sweet flavor, though they contain less sugar than white or yellow onions. They are often consumed raw, grilled or lightly cooked to accompany other foods.
12 Be sure the onion is well covered with soil, but also ensure the top of the plant's neck isn't covered too deeply. If too much of the plant is buried, the growth of the onion will be reduced and constricted. Once the plant is in the ground, firm up the soil around it.
13 Onions naturally push their way toward the surface as they form bulbs, and it helps if the tops of the bulbs are allowed to bask in full sun. For great ideas on how to cook with onions, watch my "Cooking School" show dedicated to onions. It starts with my recipe for French onion soup. http://www.marthastewart.com/1056929/french-onion-soup#1056929
14 Onions grow best when the soil pH ranges between 6.0 and 6.8.
15 Onion plants generally grow from one to three feet tall and up to a one-foot spread. It is best to rotate onion crops, so do not plant where other onion family plants have been grown in the past three years.
16 Proper plant spacing helps to increase air flow and helps to reduce both blight and purple blotch - the most common problems found in growing onions. They're caused by fungus, and are most prevalent during periods of high moisture.
17 Onions are high in vitamin-C, a good source of fiber, and with only 45-calories per serving, onions add a huge amount of flavor to any dish. Onions are also sodium, fat, and cholesterol free - just keep them away from your furred friends as they are highly toxic to pets.
18 The onion plants look great in these beds. The twine is used as each bed is prepared for planting to ensure they're all spaced equally, with walking paths between each bed.
19 Yellow onions, such as 'Ailsa Craig', 'Expression' and 'Valencia', have strong flavors. These onions are white inside, with yellow-brown papery skins. Their rich, onion taste is often used in French onion soup. Yellow onions are higher in sulphur than its white cousins.
20 Onions are relatively delicate plants. Their fragile root systems can easily get damaged by weeds or tugging. Try to manage weed growth, but be careful when pulling weeds out, so you don't end up tugging at the roots of the onions. And, if during the growing season, any of the onions flower, remove them. These onions have 'bolted' and won't continue to grow in size or flavor.
21 Water onions thoroughly after planting, and regularly throughout the growing period. Because of their shallow roots, it's important not to let the soil at the base of the plants get too dry and cracked.
22 Overwatering can also be problematic. If the leaves develop a yellowish tinge, this may indicate the plants are getting too much water, and may rot. The closest to harvest, the greater the need for water.
23 Do you know... US farmers plant about 125-thousand acres of onions each year and produce approximately six-billion pounds annually? According to the National Onion Association, the top three onion producing areas are California, Idaho-Eastern Oregon, and Washington.
24 Onions fully mature when their tops have fallen over - this happens at the "neck" of the onion, and is a signal that the plant has stopped growing and is beginning to prepare for storage. This happens around late summer or early fall. Onions should be harvested soon after - I can't wait!