The awesomeness of alliums

Garlic and onions are easy, rewarding crops to grow. Plant them this fall for next summer's harvest!

‘Silver rose’ garlic.

By Lisa Brunette

So far this late summer, I’ve encouraged you to plant now for a fall crop of carrots as well as put in some asparagus, the perfect perennial for years of spears to come. This time I want to talk about alliums.

There are hundreds of species in the plant genus allium, but the two I suggest embracing in your garden are garlic and onions.

When to Plant

In both cases, you can plant them this fall for next summer’s harvest. For me, it seems to be a tradition to put garlic and onion starts into the soil on October 31, Halloween. I’m not sure why; I wasn’t trying to bless them with the spirits of the dead or anything, but my garden records for the past two years reveal Halloween is apparently the best time to plant alliums, at least at my house. Spooky.

But you can plant them anytime between about mid-October and mid-November. The key is to wait until it cools off enough but not too late that the ground freezes.

In case you didn’t know this, one garlic clove planted in the ground this fall morphs into an entire head of garlic by next summer. It’s magic.

This summer’s harvest.

There’s also a perennial onion variety known by a number of names: multiplier, hill, potato, mother, and even pregnant onion. You can plant a bulb in the ground this fall, and it will multiply, producing many more bulbs off the main one by next summer.

In both cases, you only have to buy the starts once because you can save just enough cloves or extra bulbs to plant again each year. You can’t get more economical than that.

Where and How Many to Plant

Garlic and onions need full sun, at least 6-8 hours per day. They are good companions for orchard trees.

We’ve found that between 60-70 cloves, if they perform well and give you about that many bulbs, is enough for two garlic lovers to eat for a year.

This is how much garlic we had left by the time we harvested the next crop this summer. Worked out great!

Honestly, though, we don’t have enough potato onions, having started with only 30 bulbs and losing some along the way. I’m hoping to grow seedlings next spring from the surprise seeds I collected this year and last. That’s a bit of an anomaly, as perennial onions rarely go to seed, but I’ve had that happen twice and hope to take advantage of it, as they reportedly produce even larger varieties.

How to Plant

First, allow me to recommend Southern Exposure Seed Exchange as a source for both potato onion bulbs and garlic cloves, if you’re just getting started. Anthony and I love their ‘silver rose’ garlic, which performs very well in our climate, and yellow potato onions. Leave the skins on to plant them.

Once you have the starts in your possession and are ready to plant, hoe up a row so you can insert the cloves and bulbs to a depth of about an inch (2.5 cm) in moderate climates and up to 2-3 inches (5-7 cm) in colder areas, with about 6 inches (15 cm) between them. It’s also a good idea to add a layer of at least 2-3 inches’ mulch to protect the starts and suppress weeds. We use wood chips, which work great.

Potato onions in spring.

After that comes the waiting. Alliums survive a whole freeze/thaw/grow cycle in the ground, if you’re putting them in during the fall. While you can wait until spring, I’ve always started them in fall and had good results.

By spring, your alliums might have sprouted, maybe died off a bit during winter’s chill, and then sprung back up again. This is normal.

When and How to Harvest

We typically harvest in July, once the tops have turned brown and look ‘spent.’ Wait until the ground is dry and carefully dig them up with a pitchfork. Brush off the dirt but don’t use water. Again, leave the skins on.

You can spread the perennial onions out on a cardboard flat and store them in a cool, dry place for months, out of the sun. We store them in our basement, which is 50-70°F (10-20°C), depending on the time of year.

Potato onions in storage.

For the garlic, you can get creative and braid them if you’re using a softneck variety like silver rose. But we simply bunch and hang them in the rafters of our basement. This way they cure before going into longer storage…or you can just leave them like that all year, which we’ve done, no problem!

Garlic curing in the basement.

Don’t forget as you’re enjoying your allium harvest to set aside enough to plant the following fall. It’s best to keep the largest garlic cloves from the biggest bulbs and the most robust onions from the bulb clusters to plant later, as you’re selecting for the larger and hardier strains.

I hope you enjoy the superior taste, satisfaction, and security of growing your own garlic and onions. We’d love to hear about your experience—and answer any questions you might have—in the comment section!