Carrots love garlic, and garlic doesn’t mind carrots. Those are some conclusions I reached last year when I finally got sick of looking at all the blank space between my garlic plants and decided to do something about it. They’re planted 6 inches apart, and if it weren’t for the straw mulch between them, most of the patch would be bare dirt. Mulching dissuades weeds, shades soil from sun and blocks the wind, helping to keep moisture in the soil.Mulch comes in many forms, including "living mulches," which are sown among crops. Clover planted in corn rows is one example. But I wanted more than just a living mulch. I wanted it to be edible, too.Searching for the best crops to plant with my garlic, I developed a technique called "tossing seeds randomly." I put all the seeds I didn’t get around to planting last year into a jar, shook it up and threw them by handfuls.Last summer’s experiment identified two general plant categories good for growing in the garlic patch—what I call "garlic patch friends." The first includes fast-growing, quick-to-bolt greens and herbs like spinach, lettuce, endive, cilantro and escarole. As soon as summer heats up, these plants will go to seed (aka bolt). The plant will divert all its energy into reproduction and will often become surprisingly tall, while the leaves stop growing and turn bitter. You want to harvest and eat plants before this happens, when they’re sweet and tender. They’ll grow fast in the spring when the garlic is small, but their bolting will be delayed when the garlic is big enough to shade them. You get to gorge on these intra-garlic leafy greens in spring and early summer. By the time they go to seed, the second category of garlic patch friends will kick in.Category 2 includes crops that bide their time in the partial shade of the garlic plants early in the season, taking off in full sun after the garlic has been harvested. So far, carrots are this category’s champion. Their lush foliage functions awesomely as mulch. The roots mind their own business below ground, burrowing straight down and keeping out of the garlic’s way. I tossed a smorgasbord of carrot seeds in the garlic patch and the variety called Hercules performed best, growing as big as beer bottles. Another good late-season living mulch crop is amaranth, a long-cultivated Mesoamerican grain with brilliant red flowers.Once you pull your garlic plants from the ground, the craters left behind invite air and water into the soil. This also helps stimulate the microbial environment on the soil surface, strengthening the garden’s ecosystem.I was very happy with my garlic harvest last year and suffered no decrease in production due to intra-garlic crowding. I didn’t run out of carrots until halfway through winter, and the chickens got some amaranth. And when you count those early-season salads, I grew a pretty good bonus out of my garlic patch. This year I’m taking it a step further: In addition to my custom mix of tossed leafy green seeds, I also transplanted some escarole, radicchio and endive that were started indoors. I’m expecting these to get the early jump and grow huge while the garlic plants are still on the small side.To some extent, I’m just reinventing the wheel here. Garlic has long been known as a good companion to other crops. Garlic contains compounds that repel aphids, so many gardeners intersperse it with their lettuce and other aphid-vulnerable plants. It also plays well with roses and strawberries. While garlic’s pungent mix of aromatic compounds keeps some pest insects away, it attracts the white cabbage moth off of brassica plants like cabbage, broccoli and Brussels sprouts, and remains unharmed itself by the moths. But be warned: The brassicas I planted in the patch didn’t do so well last summer. It’s possible that while a few garlics in the brassica patch are good, brassicas in the garlic patch may not do much.Diversified agricultural environments are sometimes called polycultures. The more widely accepted name for the practice is "agroecology," which describes the ecological theory behind agricultural systems that are both productive and resource-conserving. Practitioners consider plant and insect interactions, mineral cycles, and the farm’s own socioeconomic relationships with its community, since the people who work the farm and eat from its produce are considered part of the larger ecosystem.While pooh-poohed as nonscientific by many of those in favor of industrial-style farming, the discipline of agroecology is being taught at around 15 universities, including UC-Santa Cruz, Iowa State and Penn State. A December 2010 report commissioned by the U.N. Human Rights Council examined hundreds of peer-reviewed scientific papers and concluded that agroecology has the potential to double food production in marginally productive areas. Bahian Permaculture Institute founder Marsha Hanzi has been using agroecology (she calls it polyculture) in the arid interior of Bahia, Brazil, to reclaim land that has been turned into desert by years of chemical-intensive monoculture. I’ve seen with my own eyes how Hanzi’s discoveries have helped people rebuild the soil and turn the landscape from red-brown to green with edible plants. The impact polyculture has had on the local communities is striking.My garlic and carrot garden might not work in the Brazilian drylands. But the take-home lesson, wherever you live, is to experiment with your home ground and mix up your garden just to see what happens. Whether you approach it through book learning or the trial-and-error of randomly hurled seeds, you might be pleasantly surprised by the extra yield.