Growing Onions

Onions are easy to grow, have a fairly short growing period, and importantly, they take up little space. With just one sq. ft (930 sq. cm.) of garden space, you can grow an onion or two. As a result, even the most space limited gardener usually has a few onions in the garden.

Onions are also good for your health. They were once believed to ward off evil spirits. (We recommend Garlic to be more effective for this use). Onions also have medicinal value. Recent medical studies suggest onions help to lower cholesterol and heart disease.

Home gardeners have three choices for starting onions. Seed, seedlings, and sets (or bulbs). Seeds take the longest time, and should be started indoors. Seedlings give you a jump start on growing and are hardy. They can be bought at a garden store or bought mail order.

The easiest way to grow onions is from sets which are small immature onions that have been heat treated. They can be planted in early spring for harvesting in early summer. You can plant direct into moist soil or give them a start by placing them on a tray of moist soil or peat somewhere warm until the roots have grown about an inch.

Plant onions 3 to 4 in. (7 to 10 cm) apart, in double rows six to ten in.(15 to 25 cm) apart. Leave enough room to get between the rows to weed.

Onions grow best in rich soft soil or loam. But they tolerate most soils, especially if you add sufficient fertilizer. Keep the soil moist, and allow good drainage. The root system of onion is fibrous and shallow, spreading just beneath the soil from 12 to 18 inches in depth.  Root growth is not considered aggressive; therefore onions can tolerate crowding, but cannot tolerate competition from aggressive weed growth.

 Onions are best grown on raised beds at least four inches high and 20 inches wide. Onion growth and yield can be greatly enhanced by banding a fertilizer rich in phosphorous (10-20-10) 2 to 3 inches (5 to 8 cm) below transplants at planting time. Make a trench in the top of the bed fours inches (10 cm) deep, distribute one-half cup of the fertilizer per 10 linear feet (3 m) of row, cover the fertilizer with two inches (5 cm) of soil and plant the transplants.

Nature sends a message to the onion plant to  form a bulb. that signal is warm up and longer daylight hours. Onions are biennials. They will go to seed in the second year, sending up a tall, hard stalk with a seed pod. Many growers do not know this, as we harvest our onions in the first year. Occasionally, the onions go to seed in the first year.

Pull onions when after the tops have fallen over. Rinse off dirt, and allow the onions to dry in the open air for a few days. Then, cut the tops off the onion and cut off the roots. Allow the cuts to air dry for two or three more days. This will help to seal the onion and avoid pre-mature spoiling.

Tip... To get a really early start, buy onion sets as early a possible. Place a few in some moist (not wet), loose starting mix or potting soil about two to three weeks before you can set them outdoors. They will sprout and develop a good roots system for an early start.

Most members of the onion family are resistant to insect problems. Root maggots can attack the bulbs.Tiny thrips are an occasional problem. Insecticidal soap sprays or sevin are very effective. Onions, garlic and even chives are an ingredient in a number of organic insect sprays.

The onion family is resistant to most disease. The two major diseases that will affect onions are blight and purple blotch. Should the leaves turn pale-green, then yellow, blight has probably affected the plant. Purple blotch causes purple lesions on the leaves.

Heavy dew and foggy weather favor their rapid spread, and when prolonged rainy spells occur in warm weather, these diseases can be very destructive. The best cure is prevention: use only well-drained soil, run the rows in the same direction as prevailing wind and avoid windbreaks or other protection. Should conditions persist, a spray with a multipurpose fungicide such as daconil can be applied on a 7 to 10 day schedule.