When to Plant Garlic in Zone 4 Minnesota?

The most common gardening question I get in the fall is “is it too late to plant garlic?” The good news is that the answer is almost always no, it’s not too late.

In Minnesota, we should be planting garlic in the fall, ideally in the weeks immediately following the first freeze. This is almost always sometime in October; however, it is usually safe to plant garlic any time in October, and indeed for much of November.

If the soil can still be worked, it’s almost always still safe to plant garlic. In fact, there is often more danger of planting garlic too early, rather than too late.

When you plant cloves, they will start to grow roots and begin to send up a shoot (that won’t reach the surface of the ground). As the ground freezes, the garlic will go dormant in this state, waiting for the spring warm-up to start growing again. If you plant your garlic too early, however, the shoots will break the surface and grow substantially above the ground. This can kill the young garlic plant when winter hits.

Because of this we shouldn’t plant garlic until the end of September at the earliest in Zone 4 of Minnesota — if you plant earlier it may work out, but if we have a warm fall with some rain, you risk the garlic growing too fast too soon and it may not survive the winter.

Garlic Planting Tips

Now that you know when to plant garlic (and it’s probably not too late!) here are some garlic planting tips:

• Don’t plant garlic from the grocery store. Most grocery store garlic is softneck garlic grown in California, and these varieties are unlikely to grow well (or taste good if they do grow) in Minnesota.
• Separate garlic bulbs into cloves. The larger the clove, the bigger and healthier your garlic plant will be. Consider setting smaller cloves aside for your kitchen, and only plant the big ones.
• Plant cloves root-side down, and pointy end up.
• Plant cloves in holes 2-3 inches deep. The top should be covered by around an inch of soil.
• For square foot or intensive planting, plant cloves 6 inches apart. For row planting, plant cloves 6 inches apart in double rows 6 inches apart, centered on beds, 30 inches apart.
• It’s very helpful to cover beds with 3 to 4 inches of mulch to help protect them from fluctuating temperatures in the fall and spring. Grass and leaf clippings work well (as long as there are no herbicides on your grass), or you can buy straw to cover them. Don’t use hay, which contains grass seeds!

– Written by Brian Wood, Master Gardener