Some “green thumbs” are taking an old-fashioned approach to soaring grocery bills by growing their own food.

Like people who planted “victory gardens” in response to World War II rationing, these frugal foodies are tending backyard plots of vegetables, fruits and herbs.

But can a tomato plant really save you more than $50?

It can, says Thomas Bewick, national program leader for horticulture of the U.S. Department of Agriculture’s Cooperative State Research, Education and Extension Service.

“If you harvest 30 pounds at $2 per pound, that plant is worth $60,” he says. “But it only cost $2.90 to buy the plant, a few cents for water and 15 cents for the fertilizer.”

A productive patch can really cut food costs, even after you account for the investment in gardening tools, seeds, water and time.

“Cutting the grocery bill is easy and fun for anyone with a little patch of earth and a few hand tools,” says Karen Kinnane, who cultivates a garden at her home in Pompton Plains, N.J.

However, you have to choose the right crops and avoid foolish overspending to truly harvest savings.

Choose wisely

Pat Munts of Spokane, Wash., says some foods are so inexpensive to buy at the store that planting them isn’t worth your garden space.

Munts is a master gardener, a designation given to volunteers trained by local land-grant universities (which teach agriculture, among other subjects) to educate the public about gardening and horticultural issues.

Onions and potatoes are good examples of crops you usually can buy for a great price at a supermarket, Munts says.

On the other hand, the cost of some foods quickly adds up at the checkout stand. Lettuce mixes, cherry tomatoes, peas and frequently used herbs all can be expensive. These plentiful producers are recommended for new gardeners.

Of course, regional growing conditions and market forces can change prices from year to year. For example, as ethanol production increases demand for corn, many analysts expect corn costs to spike this summer.

Not all vegetables and fruits take the same bite out of your wallet. Following is a list of the most expensive fresh produce to buy, according to the U.S. Department of Agriculture:

Gardening for groceries
Vegetables Fruits
Mushrooms. Blackberries.
Collard greens. Raspberries.
Cherry tomatoes. Cherries.
Green peas. Blueberries.
Okra. Apricots.
Turnip greens. Strawberries.
Asparagus. Pineapple.
Mustard greens. Grapes.
Kale. Plums.
Cauliflower. Avocados.

The key to sowing a money-saving harvest is to select vegetables, fruits and herbs that you truly enjoy eating, that grow easily without much work and that ripen before frost.

Roger Doiron is the founder and director of Kitchen Gardeners International, a Maine-based nonprofit that promotes “relocalizing” food.

He’s also a father to three hungry children.

Doiron and his wife turned 1,000 square feet of backyard space into a field of cucumbers and tomatoes, squash and salad greens.

Through careful, successive planting and choosing foods that the family enjoys, Doiron avoids waste.

“With an $85 seed order, we had vegetables from June to the end of January,” he says.

Doiron suggests new gardeners start easy.

“Start with salad greens,” Doiron says. “They’re easy to grow, and in many cases, if you cultivate the ‘cut and come again’ variety, you’ll get several harvests out of the same row.”

He points at the economics of salad greens: A seed packet of mixed lettuce costs $2 to $4, but generates a month’s worth of nightly salads.

“If you’re buying packaged greens from the grocery store, they’ve been in transit for a week’s time,” Doiron says.

By contrast, homegrown salad greens are only minutes from tilth to table.

“In terms of freshness and taste, there’s no comparison,” he says.

Dollars and sense

To make gardening worthwhile, you need to keep costs low.

Seeds are the least expensive option for your plot. Munts says most seed packets stay fresh for two to three years: Just keep them in a cool and dry place for next year.

“But pay a fair price for seeds,” Munts warns. “With bargain seeds and off-brand seeds, the viability is questionable.”

In other words, the seeds may be stale or low-quality, and won’t sprout.

As always, check the seed packet to see when veggies will be ripe and ready. Some foods — such as radishes — make for a quick harvest. In 28 short days, you can pluck a bunch of radishes straight from the soil.

“They’re basically just cultivated weeds,” Bewick says.

The region of the country in which you live in may dictate how much water and fertilizer you need to use. Some foods also grow better in one region than another. Plant the wrong food for your location, and you could end up babying your plants until your savings disappear.

Also, don’t spend a fortune on fancy gardening tools.

“Tools can be scrounged at garage sales and thrift shops,” Munts says.

To reduce your water bill, purchase a soaker hose (typically only around $10) and run it through the vegetable garden. Soaker hoses are perforated with tiny holes that allow water to seep out slowly and directly to the plant roots. This prevents you from wasting water through evaporation or runoff.

If you live in a high-humidity location, early morning watering is best, Munts says. If humidity isn’t a problem, water in the early evening. In either case, avoid the hottest part of the day, or the water will evaporate — along with your savings.

Compost and mulching materials are also essential to a thriving, cost-efficient garden. Weaving compost into the soil is essential to healthy plant growth. It can be bought from commercial outlets and farmers, but you can also start your own compost bin to reduce waste and provide a low-cost source of nutrition for your vegetables and fruits.

Kinnane digs holes around her tomato plants and puts coffee grounds, vegetable peelings, fruit cores and other organic matter straight into the soil.

Cutting waste
American families throw out about 14 percent of their food — around $590 worth per year — according to a study from the University of Arizona. Gardening allows families to pick only what they need straight from the vine.

Using newspaper or grass clippings to mulch around plants decreases weed activity — and the amount of time you spend in the garden.

Cutting costs is almost always a good idea. But in some cases, it pays to spend a little more upfront. While planting seeds is the most economical way to grow your own food, it isn’t always practical.

For example, Munts recommends starts for tomatoes, peppers and eggplant, which can be difficult to grow from seeds.

Flexible farmers

People with small backyards often think gardening is not a viable option. But you don’t need much dirt to put a dent in your food budget. A sunny 100-square-foot zone will provide a “salad bar” throughout summer, while a plot of land 8 feet by 24 feet can feed a family of four.

Kinnane created a veritable grocery store in her suburban New Jersey backyard, with more than 38 types of vegetables and fruits in her 540-square-foot garden. Her garden includes everything from acorn squash to gooseberries to zucchini.

She even makes back some of her expenses by selling extra tomatoes and peppers street-side.

“You can raise loads of stuff in a small space, recycle your kitchen waste, get moderate exercise for free and end up with pesticide-free vegetables for a few pennies on the dollar,” Kinnane says.

Apartment and condominium dwellers also can grow their own food by turning to container gardening.

First-time gardener Jennifer Ward of Seattle grew tomatoes, peas, lettuce and even corn in containers. Do-it-yourself growing provided a surprise benefit for her children, 2-year-old London and 6-year-old Caden.

Ward said that typically, “I can get them to eat fruit, but veggies are harder.”

However, that changed last year when Ward introduced her children to fresh, homegrown vegetables.

“They were both in tears when we ate the last of the peas,” Ward says.

Extend the harvest

Smart gardening doesn’t stop in summer. Many home gardeners preserve their crop for autumn and winter dining through one of two options: canning or freezing.

Canning is a lost art best learned from another expert, according to Doiron. Poorly canned food can lead to botulism poisoning. However, when done right, canned tomatoes, jarred jams and preserved peaches last for years.

Cooperative extensions act as a bridge between university research and consumers or farmers, and help teach skills related to agriculture and home economics.

Finding your local extension office
To find your local member of the Cooperative Extension System, check out the federal Cooperative State Research, Education and Extension Service Web site.

Munts says that while canning requires an upfront investment in jars and lids, everything can be reused for decades.

Freezing is the easiest and quickest method for preserving the modern family’s garden.

Blueberries, strawberries and other fruits can be frozen after washing, while most vegetables require a quick blanch in boiling water before heading to the freezer.

Cooks can prep tomato sauce and pesto in August, then freeze both for pasta night in November.

Kinnane dices red peppers for stir fry, chops rhubarb for pie and even has a method for savoring the last of her summer produce: She picks all the still-green tomatoes right before the first frost.

“The larger ones are wrapped individually in newspaper and put on a shelf in a cool spot,” she says. “They gradually ripen, so you have fresh tomatoes from the garden into November.”

Be sure to stick some of your vegetables into the deep freeze, including green beans, broccoli florets, sweet potatoes and sweet corn. You can also freeze fruits such as cherries, blueberries, peaches and strawberries.

For more on how to freeze and how long frozen foods retain their freshness, see the USDA-funded National Center for Home Food Preservation Web site.

Learning curve

Many successful gardeners agree that your first year might not produce a bumper crop. After all, there’s a lot to learn about your soil and how it interacts with rain, sun and insects.

But by consulting with gardening sages and asking neighbors for advice, you won’t need to bet the farm on a failing crop.

One type of local gardening expert — known as a master gardener — especially can boost your odds of success. These gardeners typically provide their help by e-mail or phone, rather than coming to your house.

“A master gardener’s services are free,” Munts says.

For example, master gardeners can help identify the type of dirt in your garden (sand, clay or loam-based soil). Knowing this information helps them to treat the soil in a way that can increase your yield.

Finding a master gardener
To find a master gardener in your community, check out the American Horticultural Society Web site.

If the garden turns out to be a bust, try other inexpensive alternatives to the grocery aisles. Munts suggests buying a membership in a community-supported agriculture farm, “if you’re looking for organic, quality produce and want to make sure your dollar works in (the) local economy.”

“U-pick” farms are another option. These farms allow you to pick produce right from the source, providing you with fresh fruits and vegetables at lower prices.

However, even if your garden wilts, you may want to try again. Amateur gardeners swear that you can’t beat homegrown, for economics and taste.

“It is something we enjoy doing (and) it’s the right thing to be doing,” Doiron says. “We’re out there in the garden with our three sons, who are seeing where their food comes from. We’re building a long-term relationship with good food.”

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