Q. I recently planted my garlic. Do I need to cover it with hay or straw to keep it from freezing?—Samuel, via email
A. "Garlic is one of my favorite crops to grow," says Niki Jabbour, author of The Year Round Vegetable Gardener (Storey, 2011). Each October, Jabbour plants several hundred cloves of hardneck garlic in her garden near Halifax, Nova Scotia. "Not only is garlic very low maintenance; it's also virtually pest-free. Even our rampant deer population doesn't nibble on our garlic crop," Jabbour says.
"Plant garlic after several hard frosts, but at least a few weeks before the ground freezes," she recommends. "This will allow the garlic to begin putting out roots but will prevent it from sprouting, which can damage the plants."
After planting garlic, cover the area with mulch. "Because I live in a cold climate (USDA Plant Hardiness Zone 5), I always top my garlic beds with a 3-to-4-inch layer of shredded leaves or straw after planting," Jabbour says. "This insulating blanket helps moderate soil temperature and protects the cloves from extreme cold. Newly planted garlic is prone to frost heaving during the freeze-thaw-freeze cycle of winter, which can damage or tear the immature root systems of the cloves."
A variety of materials—straw, shredded leaves, compost, grass clippings, seaweed—can be used to mulch garlic. Don't mulch with whole leaves, which can mat down to form an impenetrable layer. Apply dense materials such as compost in a thinner layer than straw and other lightweight mulches.
Fall mulching of garlic also results in fewer weeds come spring. But mulch isn't for everyone. Gardeners living in wet climates (where soggy mulch may promote disease problems) or those who have serious issues with rodents should avoid mulching their garlic crops.
Originally published in Organic Gardening Magazine, Oct/Nov 2013