The white onion is a bulb that grows every two years and has blue-green, hollow, tubular leaves. The bulb may push slightly above the earth as the plant ages, and a shallow network of roots extends from the bulb's bottom.
As onions have been cultivated and bred for thousands of years, many species are available today, including bulbing and bunching types, sweet and savoury flavours, and regional variations with unique applications and flavours.
Growing white onions is simple and can be done from seeds, transplants, or tiny bulbs known as "sets." Onion plants respond to day length and temperature variations by developing bulbs as they age. Therefore, depending on the local climate and latitude, when and how onions are planted and which cultivars will yield bulbs in each area. Read more!
Guide To Plant White Onions
Choose a spot where your onions will receive full sun and not be shaded by other plants. Their bulbs can get bigger the more energy they receive from the sun. To enhance texture, incorporate compost or aged manure into the autumn or early spring soil. Make sure no pebbles or rubbish are present. Compacted soil hinders bulb development. Therefore, the soil must be loose and well-draining.
When To Plant White Onions?
- Onions are planted outdoors as soon as the ground is workable in December, often in late winters.
- Start onion seeds indoors for around six weeks in the spring, then move them outside once the soil reaches a minimum temperature of 17°C.
- It takes at least four to six weeks of warm weather for an onion crop sown in the autumn to take root.
Read More: How To Grow Onions In Water: A Guide For Urban Gardeners
How to Grow White Onions?
- White onions are heavy feeders, onion plants must be fed continuously to develop large bulbs. Apply nitrogen fertiliser when it's time to plant. Before planting, many organic gardeners fill the bottom of each row with one inch of compost. Alternately, dig a trench in the ground two inches deep and three inches wide. Then, fill the trench with around an inch of compost.
- Gently press onion sets 1 to 2 inches down into loose soil, spacing them 2 to 6 inches apart. (If you wish to pick immature onions like scallions, use the closer spacing.)
- Rows should be 12 to 18 inches apart, and transplants should be 4 to 5 inches apart.
- Make sure the tip end of the bulbs is facing up. Once more, don't bury them deeper than two inches. Onions must not be planted too deeply since this may interfere with bulb growth.
- To suppress weeds and help preserve moisture, mulch with straw between rows.
White Onions Growing Tips To Note Down
- To keep them safe, conserve moisture, keep weeds at bay, promote air circulation, and ensure young bulbs are covered with light mulch,
- Avoid covering newly sprouted onions.
- For large bulbs, fertilise with nitrogen every few weeks. Stop fertilising once the bulbing process has begun and the onions have pushed the earth aside. The onion bulb must emerge above the earth; do not re-spread the soil surrounding the onions.
- If light mulch is used, onion plants don't require frequent watering. It is adequate to receive around 1 inch of water per square foot each week, including rainwater. Add more water if you want your onions to be sweeter. During warmer weather, water them frequently to prevent bolting.
- Plant carrots or tomatoes next to onions in tightly spaced rows to keep thrips away.
Harvesting White Onions
Young onions can be harvested as scallions or "spring onions" a few weeks after planting. Simply pull them when they are large enough to fit you; there is no ideal size.
To get full-sized bulbs, allow onions to develop and flourish. When the bulbs get large, and the tops start to turn yellow and topple over, they are ready to be harvested. With the tops still on, pull them up, shake off the dirt, and spread them out to cure. Onions that are very sweet and juicy can be kept in the refrigerator and wrapped in paper towels or newspaper.