Updated: Feb 10, 2019
By Debbie Roland, Master Gardener
Onions, an edible bulb and a favorite of most cooks, are a cool weather crop. Growing them at home is easy and they are more flavorful than the ones from the store.
They must be grown in full sun and well drained soil. You should be seeing bundles of onions at local nurseries now. They are inexpensive and it is always tempting to buy several. Be sure you read the tag – sometimes there are 50 to 75 in a bundle and that may be more than you need.
Examine them closely when you buy them. Like any other plant you want to to start with healthy seedlings. Check to be sure that that are not too dry from the shipping process. Seedlings about the size of a pencil are ideal.
One your soil is loosened gently push each plant about 1” into the soil. Don’t bury them too deeply. Remember that the top of the onion will actually be outside the soil when it begins to grow. Space them 6” apart. If you find that yours are too close together as they grow, simply pull some and use them as green onions.
The roots on an onion are very shallow so it is hard for them to take in moisture. They need to be watered slowly, deeply and consistently-about 1” per week. If you forget to water them, they will start growing again once watering is resumed. The more you water the sweeter the onions will be.
You will need to fertilize with a 10-10-10 fertilizer every few weeks to get big bulbs. Stop fertilizing when it pushes the soil away. This is normal, don’t push the soil back since the top needs to be above ground.
The onions are ready when the main stem begins to get weak and fall over. An onion can be harvested and used at any time during the growing process but be sure to dig them all in late summer before cool weather. Once harvested, cut the roots and top back. Spread the onions on dry ground for a few days so that they will cure. Handle carefully, even a small bruise will encourage rot. Allow to dry another few weeks before you store them off the ground on wire netting or something similar, in a single layer in a cool, dry place.
As always, you can contact the AgriLife office in Odessa at 498-4071 or in Midland at 686-4700 for more gardening information.