Do you want to try your hand at planting and growing onions here in Visalia? Onions are surprisingly easy to grow. Now, is the best time to plant here in our growing zone 9. Onions are a cool-season vegetable and will do best when planted before the soil or air warms and without the danger of frost. Onions tolerate temperatures as low as 20 degrees. Onions in zone 9 typically need 10 to 12 hours of light per day. Here are some tips how to grow onions in our area.

Should you plant onion seeds or onion sets?

What is the difference between planting seeds or sets? Onion seeds will produce smaller onions and can be planted directly in the soil and covered with a fine layer of soil in October. You will see germination of onion seeds within 7 to 10 days and by February you will need to thin them out. Your seedlings should be at least 3 to 4 inches apart. You can use the ones you pull out in garden salads or your favorite recipes.

Onion sets, when planted early, will have a longer time to produce the leafy top and larger onions. The leafy tops allow them to make more food that they store in the onion bulb. Each leaf above the ground will create one ring on the bulb. Pretty cool huh? When you plant early you encourage healthy foliage. Plant within the first fifteen days of January for larger onions. If you plant later, you’ll have some nice green onions, but not large bulbs.

How do you plant and care for your onions?

Plant your onion sets 2 to 6 inches apart into loose soil that is no more than 1 inch deep. If you want scallions, you can plant them closer. Use straw as mulch between the rows to retain moisture and stifle weeds.

Onions need moist soil to encourage healthy growth. The amount of water you need will adjust as the plants grow larger. Plan to water deeply once or twice a week to start and increase as needed with the plant’s growth.

Onions like to eat and need high-nitrogen fertilizer such as ammonium sulfate or nitrate after they’ve been planted for a month. You should apply one cup for each twenty feet and work it into the soil around the onions. Do this each month up until the month before harvest.

Each year you should change the planting location to discourage the spread of diseases that could affect your crop. You will want to choose a location that has full sun, and where they won’t be shaded by other plants. They need the energy from the sunlight to grow larger bulbs. In our area medium to short day onions will grow best. Short day onions will not keep, so you will want to use them fresh within 2 months of harvesting. Short day varieties such as Vidalia and Bermuda are sweet and are great for burgers and salads.

If you have any questions or would like to pick up your onion seeds or sets stop on by Luis Nursery and we’d be happy to help.