Sweet onions refer to several onion varieties, including Walla Walla, Vidalia, Sweet Spanish onions, and more. These varieties of onions naturally tend to be less pungent than others. The best commercially grown sweet onions like Georgia and Vidalia come from parts of the world that have naturally low levels of sulfur in the soil which they got their name from. Sweet onions are starting to become wildly popular and growing them can be a little tricky.
Some of the most important things to remember about growing sweet onions are that they need plenty of sun, and fertile well-draining soil.
Getting the Garden Bed Ready
Have the intention of planting from early to mid spring. Planting onions can be done between four to six weeks before the last frost. As soon as the ground can be worked in March or April, prepare the garden bed for planting and don’t plant onions until the temperature ceases to drop below 20 F (-6.7 C).
Plant your onions in a bright, non-tree, or other plant shaded sunny location that exposes your onion to direct sunlight of about 6 to 8 hours per day.
Soils should be amended with compost. A loose, fertile, and well-draining soil with a pH between 6.0 and 6.8 gives your onions the best chance. Break up the soil in the garden bed with a tiller and Spread 2 inches (5 cm) of matured compost or aged manure over the garden bed and work it into the soil with a tiller. The use of compost to amend the soil will add nutrients and allows for proper draining of the soil.
Don’t forget the loose grounds allow sulfur to drain through. Otherwise, the onions won’t be as sweet. Addition of fertilizer to the soil to amend the soil with extra nitrogen. A nitrogen-rich fertilizer like blood meal should be sprinkled over the soil and Use a rake to mix the fertilizer with the soil. Sulfur-based fertilizers should be avoided when growing sweet onion to avoid making the onions more pungent
Planting and Caring for Sweet Onions
Use your hands or a spade to build the soil up into rows that are 4 inches (10 cm) high after creating space in the soil and use your hands or a spade to build the soil up into rows that are 4 inches (10 cm) high. It is important to Plant sweet onions in rows or raised beds as this helps drain the water better and produce sweeter onions. It is not necessary to create rows before planting because you have completed your control over the soil medium in the container.
Plant the onions in the rows. Use a spade to dig 1-inch (2.5-cm) holes in the rows. Space the holes, so they’re 6 inches (15 cm) apart. Place an onion set (A small onion that was grown and dried the previous year), in each hole and cover the roots with soil. Planting must not be more than an inch (2.5 cm) deep so the leaves won’t rot and bulbs will grow large.
Cover the soil with a thin layer of mulch as this will help to eliminate weeds from the area and keep the soil consistently moist, which is ideal for onions. Good mulches for onions include a light layer of grass clippings or straw.
When the onion bulbs start to grow, sweep the mulch away from the bulbs to keep the onions dry.
Keep the soil moist as the onions will need regular watering to keep the soil damp because these plants have very shallow roots. Provide the onions with about an inch (2.5 cm) of water each week, minus whatever water they get from precipitation. You’ll have to provide even more water if you didn’t add a top layer of mulch. If the leaves start to yellow prematurely, waterless because this means they’re getting too much.
Use a rake to mix the fertilizer in with the soil before watering. Side dress the onions again when the tops reach about 8 inches (20 cm). When onions flower, it means they have bolted, or are going to seed, so they need to be removed. Flowering onion bulbs that are left in the ground will start to rot.
Harvesting and Storing Onions
Once the bulb reaches maturity, the scapes and leaves start turning yellow and fall over. Wait for the scapes to die back for mature onions. Onions that are left in the ground to mature will eventually start to form larger bulbs. This shows the onions are ready for harvest. The onions might be ready anywhere from 90 to 110 days after planting depending on the variety
On a sunny morning, pull the onions from the ground. Place your hand on the scapes and leaves of the onion near the base, pull it from the ground gently and Shake the onion a bit to remove excess dirt from the roots. Ensure you harvest the onions by late summer since the cooler temperatures of fall will only cause them to spoil.
Curing is the process of allowing the skins to dry, and it will facilitate more extended storage. Because sweet onions don’t keep as long as pungent onions, you don’t have to cure them for as long. Cure the onions. After you’ve harvested all the onions, expose them to the air and sun by spreading out on the soil. Leave the onions to dry in the sun for nearly three days, until the crown and skin are dry. The skin should also be examined to have a uniform texture and color. Cure the onions inside in a well-ventilated area during wet weather
Sweet onions should be used within six weeks since they don’t tend to last as long as regular onions. Wrap the onions individually in paper towels and store them in the refrigerator to elongate the shelf life up to 8 weeks.
With the tips above, you can now start you sweet onion planting in your garden.