Onion and Garlic Harvest

One of our favorite events in late Spring here at the Rural Studio Farm is digging up all of the tasty onions and garlic. These alliums—along with shallots, leeks, chives, and scallions which we also grow—are versatile, easy to grow, and keep for a long time in storage.

Two students excavate mature garlic bulbs from a raised bed

Onions

Onions likely originated in the Middle East and Central Asia and have been cultivated for around 7,000 years. There are short-day and long-day onions, so named because of the number of daylight hours that signals the plant to start forming bulbs, which are modified stems that serve as a food reservoir for the plant. As Earth approach the Summer Solstice, daylight hours increase and days grow longer the farther from the equator one goes. So here in the South, short-day onions perform much better, while regions above about 37° latitude are more suitable for long-day onions because of the added day length.

For short-day onions, the earlier they are planted, the larger the bulbs. We plant our onions in February here at Rural Studio. This year we grew onions from both seed (started in January) and onion sets, which are small onion plants that were shipped to us. Both varieties are sweet onions: one is a Walla Walla-type that is suitable for growing in the South (Walla Walla is in Southeastern Washington), and the other is a Vidalia-type onion. These two regions are famous for their sweet onions because they boast volcanic soil that is low in sulfur. The low sulfur content means that onions grown there are mild. It is the sulfur-containing compounds that give onions their tear-inducing pungency and sharp flavor. Unfortunately, these same sulfur compounds, like allyl disulfide and allicin, are also responsible for many of the health benefits associated with eating onions (as well as garlic).

Once the tops begin to dry out and fall over it means that the onions are ready for harvest. After they are harvested, we then laid the onions out to cure with the tops and roots intact because any cuts can allow pathogens to reach the bulb and cause rot. During the curing process, the tops dry out and so does the outer skin, protecting the onions so that they can keep for months in storage.

Garlic

Garlic is one of the oldest cultivated crops in the world and most likely originated in Central Asia. In most regions, it is best to plant garlic in the Fall because you get larger yields than Spring-planted garlic. We typically plant ours in November, like we did for this year’s crop. It is important to mulch the garlic to suppress weeds, protect the plants during the winter, and retain moisture as the weather warms moving into Spring.

Just like onions, there are two types of garlic: soft-neck and hard-neck. Soft-neck garlics have smaller, more numerous cloves and generally keep in storage very well. Hard-neck garlics, on the other hand, are more winter-hardy, produce fewer cloves, often have stronger flavor, and produce a long edible flower stalk called a scape. We have grown both kinds of garlic here at the Rural Studio Farm; however, this year we only grew an unknown hard-neck garlic that we received from one of our neighbors.

The garlic will set scapes in mid-Spring. They are best harvested when they are young and tender, like asparagus, and they make for excellent eating. It is generally recommended to cut the scapes anyway, as they can draw nutrients away from the bulbs and reduce yields. If left, however, the garlic will produce a large globular light-purple inflorescence of flowers called bulbils. This year, we let the garlic flower and were rewarded by an abundance of butterflies and bees.

The time to harvest garlic is when the bottom two to four leaves begin to wilt and brown. Each leaf corresponds to an individual clove, and the browning indicates that the cloves are no longer actively growing. Like onions, the harvested garlic must cure for about two to three weeks to dry out and make suitable for long-term storage. The roots and necks of the garlic will only be trimmed once the heads have had time to fully cure. Most of them we will eat, but we will save some of the harvested bulbs to break apart and plant again this Fall.

This year we harvested 427 pounds of sweet onions and 67 pounds of garlic. We’ll be enjoying onions and garlic for many more meals to come!