Can I plant garlic in December?

I wanted to address this question because I get it quite often. The simple answer is yes. Even in upstate New York, garlic planted in December will do quite fine. I'm a morning walk away from the 43 degrees north latitude, and a Zone 5 climate, where mid October is the ideal planting time, and November or December plantings are not a problem.

I'll share a couple tips on how to get a December garlic planting done, because while it's not ideal, it's still doable and certainly better than no garlic at all!

First off, it's not ideal because the plant will have less time to establish roots than if it'd been planted on time in October. But, it's a tough plant, and roots will grow at 32 degrees Fahrenheit and higher. On a couple sunny days in December, it'll grow enough roots to stay alive, and sprout new top growth (green shoots) by spring. With a couple tricks, you can even help it make up for lost time.

Plant the clove 3 or 4 inches deep (from basal plate to the soil surface), using a trowel to open up a nice slot in the soil to plant it into. If you don't have a trowel handy, just use a junky old kitchen butterknife or something else with a thin blade. You don't want to compact the soil, so don't just jam the clove in or use other blunt instruments, or else you'll create a little launchpad for the roots to push against, and it may heave the clove out of the hole. I've done this before, it's a texture issue that arises especially with supersoaked cold soil.

planting depth of garlic

It doesn't matter if you have to slice through 2 inches of frozen mud, if it's thawed at 3 inches, then the roots will grow. Remember, they grow at 32 and above!

If the day you have available to plant is too cold, you can rake a bunch of leaves onto your garlic spot as soon as you can (days before!) so it's more likely to be thawed when you get there. Depending on the size of your plot, you could place a 30 gallon black trash bag on that location (pinned with rocks), and that'll help heat it up to thaw on a sunny, below-freezing day. Any little trick to get the soil thawed and your garlic in, is good.

If the forecast has mostly sunny days for the remainder of December after you've planted your garlic, leave your dark soil exposed, to gain as much heat as it can. If it's mostly cloudy, you are better off opting to mulch your garlic with leaves or straw- since the sun isn't there to help, your new goal is to trap in whatever heat the soil has, using the organic matter. 2 inches of thickly matted wet leaves, or 4-6 inches of dry leaves, or 5 inches or so or straw, is the appropriate cover. Drier materials are better, but don't turn your nose at wet stuff, it's better than nothing! If the nighttime cold is enough to penetrate 2 inches of material, better 2 inches of wet leaves than 2 inches of soil.

If you have ever used rowcover to protect frost-sensitive crops, you can deploy some to get a few extra degrees worth of heat for your garlic for a few weeks, this can help it play catchup. If not, don't worry about it.

This garlic won't yield as well as the ones that got a full month or more of root growth, but it'll still turn out fine. These tips are just to help mitigate some of that loss, but if all you can do is drop the cloves in 3-4 inches into not-yet-frozen soil, most of your garlic will survive and be fine.

If you have any questions, email me here !

PS- it's worth noting, that the more "winter hardy" a garlic is, the more likely it will survive late planting. There are some garlics for which even on-time planting cannot stop them from losing a certain percent of cloves to winter loss in a given year. I have found that the losses are not so catastrophic to stop me from late-planting when I've had to do it. It is harder and slower, so certainly not a habit to fall into, but totally doable!

Later-planted garlic may need its mulch removed, since fewer roots are there to power up a green shoot through the thick mulch. If it had been planted on time, the plant would have a much larger resource base to power that shoot through with. You temporarly remove the mulch in late March or early April, when the shoots may be struggling to come up, and once they're up, you may re-set the mulch around the plants, for continued weed control.