the tricky matter of when to harvest garlic

TIMING IS EVERYTHING, they say, and with garlic harvest that’s especially true. But since the crop is hidden underground, how do you know when this edible Allium is ready—when it’s just the right moment to insure a well-formed head that will also store well through the winter and beyond? Like fortune-telling, it’s all in reading the leaves, apparently. When to harvest garlic–and how:

Don’t let its relatives mislead you. Garlic’s close cousin, the onion (Allium cepa), is more adaptable about its ideal moment to be lifted and cured. You can simply let the tops (leaves) die down right in place, delaying digging a bit to when it’s convenient. Or if you’re in a rush, move things along (assuming the bulbs are well-formed) by knocking over the foliage to urge the plants toward their finale.

With garlic, though, waiting until all the leaves go brown will promote overripe bulbs whose cloves are starting to separate from one another, and the resulting un-tight heads won’t store as long. Each leaf that browns is one fewer potential wrapper to protect the bulb. (Counterpoint: Harvesting too soon can also diminish the bulbs’ shelf life in storage, and may limit the bulbs reaching full size.)

Most experts say to harvest when several of the lower leaves go brown, but five or six up top are still green—and depending on the weather, this typically happens here in my Northeast garden in late July. Above, those are a few plants just as they came from the ground one year. Early bouts of sustained spring heat can push the garlic a little ahead of schedule (as with so many other plants), and have my harvest curing extra-early, a process that takes three to eight weeks, before the tops will be cut off, the roots trimmed, and the cured bulbs stored.

In the curing there’s another difference between the most popular Allium cousins, garlic and onion: Assuming it’s a dry day when harvest comes, onions can be left out to dry right beside the rows you dug them from. Not so with garlic, which should be moved out of direct sunlight immediately once unearthed. Move it to a garage or porch or shed where the air circulation is good.

Harvesting garlic couldn’t be easier, as long as you remember one thing: Though tempting, do not try pulling the bulbs out by the above-ground stems, or at least without first loosening the soil alongside each row with a spading fork (not too close to the heads!). Garlic stores best when cured with its leaves on.

Other factors that affect the timing of garlic harvest besides the weather, is what kind of garlic you planted.

Softneck garlic (Allium sativum), the most common type of supermarket familiarity, has a row of largish outer cloves and a row or two of inner small ones. It would keep better than what I grow, but I like the bigger (though fewer-per-head) cloves of the hardneck kind…

…because hardneck garlic (Allium sativum var. ophioscorodon) is better-adapted to Northern winters (its long roots hold it in the heave-and-thaw ground especially well), and frankly I just hate all those tiny inner cloves of softneck at peeling time. Nor does comparatively puny softneck make as nice a roasted head of garlic as the bigger-cloved kind.

Hardneck kinds also send up a scape—really a woody flower-stalk-to-be—around June, signaling a month or so remaining before bulb maturity. I cut the scapes off when they start to develop (above), and use them in stir-fries, oiled and grilled, or pureed with cheese as a pesto on pasta. I’m not being selfish by harvesting them then (though they are delicious); rather I’m telling the plants to put their energy into bulb production, not sexual reproduction.

Most experts agree that is the benefit of removal, though some say leaving it on produces better cloves for replanting as your “seed” stock. I frankly have no idea what’s true (as with so much of gardening, you go on gut); I cut them off.

I make it all sound like a lot to ponder, but garlic is easy to grow. It took me a mere 15 minutes to harvest my crop of about 75 heads today, and not much work before that, frankly, either.

Once cured, I’ll stash most in a cold, dark spot–and freeze a portion of my harvest, so I have my own garlic all year round. More on storing (and freezing) for the long haul.

how i got to harvest: growing garlic

GARLIC IS PLANTED in the fall, around October locally in the Northeast, with the biggest and best cloves from the biggest and best heads of last year’s harvest chosen to use as the “seed garlic” or start of the next crop. (The full how-to on growing is here.)

I’ve also written before about harvest and curing details here (along with the subject of multiplier, or perennial, onions—which I didn’t do so well with in my Northern garden but mean to try again, but that’s another Allium story for another time).

the garlic stories

• Overall garlic-growing basics
• Growing and storing a year of garlic
• Harvest and curing details