How can you get the most yield from a garden where space is limited, and water is too?
Plant smart, and pay attention to the soil.
"Your garden is only as good as your soil," says David Salman, chief horticulturist at High Country Gardens, a Santa Fe, N.M., catalogue that specializes in native and low-water plants.
Find out what nutrients your soil has — and what it's missing — with a soil test, available through local co-operative extension offices at a nominal fee (home soil-test kits are less reliable, according to the Colorado State University Extension).
Encourage plant health by fertilizing with natural, organic fertilizers, which include fish emulsion and liquid seaweed, says Salman. Limit the use of chemical fertilizers because they don't help build the soil.
"You will have more nutritionally complete vegetables if you have healthy soil," he promises.
One trick Salmon recommends, especially for gardeners living in new housing developments, is adding a soil inoculant called mycorrhiza, a beneficial fungi. It's found naturally in healthy soil, but often needs to be added to a new garden.
"New gardens in new subdivisions, their soil is scraped off as part of construction," says Salman. "You need to put beneficial fungi back in."
Peas, beans and soybeans could benefit from legume inoculants, which are species-specific (a soybean inoculant cannot be used to improve peas' growth). Read product labels carefully or ask your gardening centre for assistance.
"Your beans will do OK (without it), but if you really want to crank out the beans, you can do that with the inoculant," says Salman. "It's kind of a 'grandma's secret' to growing great beans."
Plants that can offer high yields with low watering include leafy vegetables such as kale, lettuce and spinach; beans, snow peas and sugar snap peas; and some varieties of cucumbers and squash, he says. Plant vining beans and peas if you have space or can grow them up a fence or trellis; plant bush beans and peas in large pots if space is limited.
Sarah J. Browning, an extension educator for the University of Nebraska-Lincoln, suggests planting radishes, carrots, peppers, zucchini and summer squash for summertime bounty. Peppers grow well in dry conditions, says Browning, and root crops such don't need frequent watering.
"If you watered them well and then mulched them, I think you could get a crop with fairly small amounts of water input," she says.
Plant radishes early in the season or in part shade, and mulch them and other plants to retain moisture and combat weeds.
Browning recommends the cherry tomato cultivar Sun Gold and the slicers Big Beef and Celebrity as great-tasting high producers. Also look for disease-resistant tomato varieties, which are easier to grow. Browning refers tomato lovers to Pennsylvania State University's College of Agricultural Sciences Extension's "Tomato Report 2011," which lists the best varieties in its tomato trials.
Melissa Ozawa, a features editor for gardening at Martha Stewart Living magazine, recommends growing okra and Swiss chard; both are heat- and drought-tolerant. Melons also can handle less water once established because of their deep root systems, she says.
Not all vegetables grow well in all regions, so read seed packets, matching days to maturation to your region's growing season, Salman advises.
"One of the big problems with horticulture in this country is everyone tries to be one-size-fits-all, and this is just too big of a continent to do that," he says. "You don't want to grow a 120-day watermelon in Denver. They can grow those in Texas, but the maturation period in Denver is much shorter."
Prolific, water-wise herbs include basil, oregano, parsley, thyme and rosemary, says Browning.
Salman offers space-saving planting tips for herbs: Plant lavender and oregano along the dryer edges of your garden, since they're the most heat-tolerant, and plant Greek oregano and dill, plus annual herbs such as basil and cilantro, among the root vegetables.
Try growing perennials such as rosemary, English thyme, tarragon and lavender in your ornamental beds. They don't require your vegetable garden's mineral-rich soil, says Salman.
Drought-tolerant flower varieties include coneflowers, hummingbird mint, salvia and blanket flowers, according to Ozawa. Other cutting-garden winners are cosmos, zinnias, sunflowers and larkspur, says Salman. His favourite late-season bloomer is the Mexican sunflower.
"If there's a bee or butterfly in a 10-mile radius, they'll find that Mexican sunflower," he says.