Frequently Asked Questions

Onion Plant Care

Should I water the onions when I first plant them? Yes, the transplants should be watered immediately after being planted. They won't grow new roots unless the soil is loose and moist, so it's important to maintain adequate moisture. Avoid overhead irrigation, which encourages foliage diseases.

How often should I fertilize? The first application should be three weeks after planting; then repeat the process every 2-3 weeks. Stop fertilizing when the onions start to bulb, which is about three weeks before harvest.

Should I pull the dirt back from the onion when it starts to bulb? The bulbing process is gradual, and there's no reason to pull dirt away as long as you keep the soil loose. In fact, pulling the dirt away can cause sunscalding (sunburn) of the onion skin. Remember that the bulbing process requires more moisture in any case; if you increase watering, the soil should remain loose.

Harvesting and Storage

How do I know when my onions are ready for harvest? An onion is fully mature when the top falls over. Bending the top over will only stop the bulbing process, so don't be too eager to harvest. You don't have to wait until all the tops fall completely over to harvest, but harvesting early may cause the onion to sprout during storage since it hasn't finished the bulbing process.

How do I harvest? Once the tops have fallen over, pull the onions out of the ground and let them dry in the garden for a few days. It's a good idea to cover the bulb of one onion with the top of another to prevent sunscald. When you remove the onions from the field, clip the roots at the base and clip the tops as well, but leave 3/4-inch of the neck to seal and protect the interior from decay. Discard any decaying onions. Never let a single decayed onion touch another, since the decaying process will spread.

Any tips for storage? Store your onions in a cool, dry place. Sweet onions store for a maximum of three months, but storage types will last throughout the winter. The best way to store them is in mesh nettings or pantyhose, hung in a well ventilated area.