Sometime in May, depending on the weather, it’s time to plant the more cold-hardy vegetables: peas, broccoli, onions and other root crops. They can sustain moderate frost, but it’s always a good idea to cover them at night if cold temperatures are forecast.

Onions are easy to start from seed in early March if you want a particular variety not available in sets. Generally the sets found for sale are simply designated red, yellow or white onions. If you are planting a lot of onions, be sure they specify they hold up well in storage.

Some gardening articles claim that stored properly, onions can keep for a year, so it’s possible you could harvest and keep all the onions you’ll need until next harvest. At least that’s my personal goal this year.

I intend to plant 60 yellow onion sets in one bed because yellow are what I use most for cooking year-round. Before planting, it’s recommended that the sets be soaked in compost tea to ward off fungal diseases.

Compost tea is simply made by shoveling rich compost into an old pillow case that is left to soak in a bucket of water for a day. Then toss out the pillow case, and what remains is compost tea.

Since onions prefer a slightly acidic soil, and since our native soils are definitely alkaline, the bed will need lots of good compost and organic matter added to it. The sets (or plants, if started from seed) should be planted an inch deep about four inches apart.

They should be watered well when planted and given about one inch of water per week throughout the growing cycle.

Most problems can be prevented by keeping the leaves as dry as possible. Watering is best with a soaker hose or drip system rather than sprinkling from overhead. It is also very important to remove weeds in the bed, as they will deprive the onions of needed water and nutrients.

The tops of the onions will fall over on their own as the growing season nears the end. Stop watering for the next two weeks, and then carefully dig up the onions. Leave them lying on the ground for a few hours to dry and then spread out in a dark dry place to finish drying.

You can braid the tops, secure with twine and hang in a well-ventilated area, or snip off all but an inch or two of the tops and store in mesh bags or ventilated baskets. They should be stored in a cool and dry place between 30 and 50 degrees.

If all works well, you should be eating the last of the previous year’s harvest just as you’re bringing in this year’s new crop.

The Colorado State University, Colorado Master Gardener Program volunteer network strives to enhance Coloradans’ quality of life by extending knowledge-based education throughout Colorado communities to foster successful gardeners.

For information, call the CSU Extension, Elbert County Master Gardener office at 303-621-3162.

For additional information on growing onions, you can find several publications on the Colorado State University Web site. These are just a few: Planttalk 1808: Growing Onions from Seeds; and Garden Notes #719: Vegetable Garden Hints.

Doris Smith is a Colorado Master Gardener.