Red Onions - Tips For Growing Red Onions

Onions can be tricky to grow if they’re not planted at the right time. If planted in cold weather, they can die off or waste energy in blossoms rather than bulbs in the spring. If you’re planting seeds, start them indoors at least 6 weeks prior to planting outdoors. Onions can be planted outdoors at the end of March or beginning of April, or whenever temperatures do not drop below 20 °F (−7 °C).

How to Grow Onions

1. When you’re ready to plant, till the soil about 6 inches (15.2 cm) deep and add a layer (1 cup per 20 feet) of phosphorous fertilizer. Using a mixture such as 10-20-10 or 0-20-0 will provide an extra boost for your developing onions. At this point, be sure to remove any weeds that may be present in the garden plot you’re planting in
2. Plant onions so that no more than one inch of soil is placed above the sets or seedlings; if too much of the bulb is buried, the growth of the onion will be reduced and constricted. Space onion sets 4–6 inches (10.2–15.2 cm) apart, and onion seeds 1–2 inches (2.5–5.1 cm) apart. As your onions begin to grow, you can transplant them and space them further apart in order to increase their growing size.
3. Place your seeds in the holes you’ve dug, covering them with ½ to 1 inch (2.5 cm) of soil. Use your hands or shoes to firmly tamp the soil over the top of the onions; they grow better in firm, rather than loose, soil. Finish up planting by adding a bit of water, and you’re set to watch them grow!
4. Onions are relatively delicate plants, as they have a fragile root system that can easily be damaged or abused by weeds and tugging. Use a hoe to cut off the tops of any weeds that emerge, rather than pulling them out; tugging the weeds could tug out the roots of the onions, and make growing difficult. Give your onions about 1 inch (2.5 cm) of water per week, and supplement with a nitrogen fertilizer once a month for nutrients. One month after planting, add a layer of mulch between each plant to lock in moisture and block out weeds.
5. Onions are fully ripe when the tops appear golden yellow; at this point, bend the tops so that they lay flat on the ground. Doing this will move further nutrients towards developing the bulb rather than growing the shoots. After 24 hours, the tops should appear brown and the onions are ready to be pulled. Remove them from the soil and trim off the shoots at 1 inch (2.5 cm) above the bulb and the roots. Leave the onions to dry out for a day or two in the sun, and then move them to a dry space indoors for 2-4 weeks to continue drying.