Garlic is one of my most dependable garden crops, which almost always does well when planted in October. But lately I’ve been wondering if I’m doing it right. My practice has been to grow garlic in its own bed, but this year I’m changing things up. In addition to growing part of my crop the old way, I will be using garlic as companion plants for next year’s cabbage and peppers.
Garlic’s history as a beneficial garden plant go back a thousand years, but until recently it has been difficult to separate facts from superstition. Then there is the complicating factor that garlic is grown from autumn to midsummer, while most vegetables are planted in spring. Because of this calendar disconnect, companion planting with garlic requires advance planning, but it’s worth some extra brain work. In recent studies from around the world, companion planting with garlic has been found to deter some insects and invigorate the soil. Companion planting with garlic can also make better use of limited garden space, a major benefit to most gardeners.
Garlic with strawberries
Last year, researchers in Brazil published an interesting paper on the effect of various companion plants on strawberry spider mites. First they looked at chives, coriander, fennel, garlic, oregano and sweet marjoram. Fennel and chives showed some promise, but garlic emerged as the star. When dense, double rows of garlic were planted between rows of strawberries, spider mites were reduced by 44 to 65 percent.
This may not surprise Russian gardeners, who often plant garlic with their strawberries. In your garden, you might fill openings in strawberry beds with garlic, or to plant garlic in a widely spaced double row, with strawberries in the middle. Depending on your climate, you might plant the garlic now, mulch over the bed through winter, and add the strawberries in early spring.
Garlic with spinach
Spinach is one of the few vegetables that match garlic’s winter hardiness, so they make natural partners for the winter garden. I’ve tried planting spinach between double rows of garlic in the fall, and it worked well enough for the garlic, but not for the spinach, which needed more winter protection.
However, waiting until early spring and plugging spinach or lettuce seedlings between double rows of garlic can work very well because the greens do such a good job of suppressing weeds during garlic’s most active season of growth.
Garlic with peppers
In China, researchers found that a triple row of garlic, with peppers planted on the outside of the garlic, had an invigorating effect on the soil, probably because garlic feeds beneficial soil microbes with substances exuded by its roots. Sounds good, but the timing is tricky when you’re pairing cool-natured garlic with heat-loving peppers.
The good folks at the Sustainable Agriculture Project at Michigan’s Grand Valley State University may have figured it out. They planted a triple row of garlic as usual in the autumn, harvested the middle row as green garlic in early summer, and planted peppers in the opening. The garlic helped protect the young peppers from pests and predators, and was harvested before the peppers needed more space. Recent Chinese research suggests you might do the same thing with eggplant.
Garlic with cabbage
In some studies, companion planting with garlic effectively defended cabbage from diamondback moth, cabbage white butterfly and other chronic pests. I’m still going through an intensive cabbage-growing phase in my gardening life, so I’m planning to install little 3-plant pods of garlic at 3-foot (1 metre) intervals in next spring’s cabbage row. The garlic will need to be well marked, but I can already envision how well this planting scheme will work. Both crops should mature at the same time in early summer.
Garlic with oats
As for my bed where garlic is the primary crop, I’ll be companion planting the garlic with oats. When used as an autumn cover crop in my area, oats grow at least ankle high before they are killed by cold weather. The collapsed plants form a beautiful mulch, which should suppress winter weeds and protect the garlic bed from erosion.