Imagine getting the same amount of garden produce using only 20 percent of the space you used to plant.

As added incentive, you’ll also have healthier plants, fewer weeds and less physical strain when it comes time to reap what you’ve sown.

That is the gospel according to Mel Bartholomew; a grinning, gregarious man in a straw hat who wanted to revolutionize the way Americans grow vegetables.

He is, after all, the father of square-foot gardening, a method of planting brought into the national psyche 30 years ago and promoted on public television.

The biggest mistake people make, he says, is going overboard.

“It’s so easy to put more and more in,” Bartholomew said in a recent interview from his home outside of Salt Lake City. “You get carried away.”

Downsize

Rather than planting in conventional rows, Bartholomew wants you to downsize. Start with a 4-by-4-foot raised box filled with the perfect soil and assigned a grid pattern so each plant variety has its own square-foot section. That may mean only one head of broccoli in one square and 32 radishes in another.

HOW TO Square-foot gardening Step 1: Start with a 4-by-4-foot area

Step 2: Remove weeds from soil surface and level

Step 3: Use 2-by-6-inch boards plus hardware to join the ends together

Step 4: Fill inside with 6 inches of soil, using equal parts of peat moss, coarse-grade vermiculite and blended compost. Mix well and spread evenly.

Step 5: Nail six lengths of wood strips — three east-west and three north-south — to delineate 16 square-foot planting areas. • The 4-by-4-foot garden will allow for 16 plants (vegetables, flowers and herbs), each in its own 1-foot area.

• Use multiples of 1, 4, 9 and 16; depending on plant variety and fit per square foot. Then, space them out.

• Start with staples: green onions, carrots and herbs. What to plant Here’s an example of what you can harvest from one 4-by-4-foot box in one spring season: • 1 head of broccoli

• 1 head of cauliflower

• 4 heads of romaine lettuce

• 4 heads of red lettuce

• 9 bush bean plants, placed 4 inches apart

• 16 carrots

• 32 radishes Grow plants vertically, using a trellis or netting. Plants that can be grown this way on the outside squares include: • 1 summer squash

• 1 tomato

• 2 cucumbers

• 8 pole beans

The smaller area is easier to reach from the sides, and climbers — such as pole beans, cucumbers and tomatoes — grow up rather than out.

“Growing our own groceries can be fun and money-saving,” Bartholomew said. “And a little planning can keep excess vegetables from causing headaches for the cook and the neighbors.”

Planting a garden — either the conventional way or the square-foot way — seems to be catching on, according to a recent survey by the National Gardening Association.

An additional 7 million families grew vegetables last year, up 19 percent from 2008. That number is expected to increase by 10 percent this year.

Hands-on training

As a civil engineer, Bartholomew oversaw installation of utilities — such as sewers, drains, electrical lines — on college campuses.

“Everything that runs the place,” he said.

After retiring in 1972, the “frustrated weekend gardener” started tinkering with methodology of gardening, like having 25-foot rows spaced 3 feet apart.

“I asked the agriculture experts why you have to have 3-foot spacing between rows,” Bartholomew recalled. “They said so you can get between the rows and weed. Wait a minute; I don’t want to weed.” The tradition of planting in rows, he concluded, is fine for commercial agriculture but not a backyard garden. He planted a field on Long Island, N.Y., using his square-foot method as part of the nation’s bicentennial celebration in 1976.

Five years later, his book, "Square Foot Gardening," was published, and Bartholomew launched a show by the same name on public television.

The program ran five years and is the highest-rated PBS gardening show to date. A second weekly show, “The Square Foot Show,” aired on Discovery Network.

He has met with pockets of resistance, mostly from makers of products that aren't required — or used a lot less — in square-foot gardening.

“Some of the tool companies were reluctant to sponsor me because I came in with a wheelbarrow full of tools and asked the audience, ‘You know how many tools you need? You don’t need any of them, other than a little trowel.’ That ended sponsorships,” Bartholomew said.

No digging

“Square Foot Gardening” was revised in 2007 to make it less strenuous. His first book advocated digging down 6 inches and adding another 6 inches of amended soil.

Now, you don’t have to dig, just fill the 4-by-4-foot frame with 6 inches of soil. The “soil” is a mix of equal parts peat moss, coarse-grade vermiculite and blended compost.

“How can you grow in soil only 4 to 6 inches deep?” he asks, rhetorically. “I experimented and found that every single plant — even tomatoes — grows in 6 inches of soil. Roots roam looking for nutrients and water. Put in the box, fill it with the perfect soil blend and get going.”

The perfect soil blend, he notes, is packaged and sold in Utah under the name Mel’s Mix. He hopes to bring Mel’s Mix to garden centers across the U.S. In the meantime, people can make their own using bulk packages of peat moss, coarse grade vermiculite and blended compost.

His latest book, “The All New Square Foot Gardening Cookbook,” released this year, walks you through the gardening steps — from planting seeds to putting your harvest on the dinner table.

Don’t worry; it’s not rocket science, he assures.

“First of all, we deal with non-experts, mostly people who are afraid to start a garden or who started a garden and failed because weeds took over, and plants didn’t grow like they were supposed to,” Bartholomew said. “This method also targets a generation too busy to garden or those who used to garden but are too old to lean over and do the work.”

Proper planning

Building the square-foot garden frame needn’t be expensive, either. Untreated lumber at least 6 inches wide, which costs about $6.50 at a hardware store, will do.

Once you have your box on level ground and the soil mix distributed, think about what your family eats. Don’t grow turnips if no one likes turnips.

Nor is it necessary to plant everything at once, consider the turn-around time between planting and harvest. Cool-season vegetables, such as radishes and lettuce, can go in now.

Heat-loving crops, such as tomato and pepper, are best planted around Memorial Day weekend.

Also, don’t underestimate the mature size of what you’re planting, Bartholomew said.

“Think about a mature zucchini plant, and how many zucchinis you were leaving on people’s doorstep last summer because you planted too many.”

“Like gardening in general, a lot of trial and error goes into this planning,” he said. “Eventually, you’ll develop a personal planting guide with a flow chart from seed to table.”

He likes to tell people to think like a chef.

“Plan your vegetable garden from the dinner table backward,” Bartholomew suggests.

“That’s the secret to more rewarding and economical gardening — planting things your family will actually eat.”

Tips to grow your own vegetables

Think of the harvest when planting; what will a mature plant look like and produce?

• Plant according to harvest times. Leaf lettuce takes 45 to 50 days to mature from seed and about a week to sprout.

• Take a salad bowl, scissors and bucket of water to the garden. Clip spinach, lettuce, Swiss chard, radish, a few carrots and wash in the water. Your salad is ready,

• Take the kids to the grocery store and have them point out what fruits and vegetables they’ll eat. Plant what they like.

• Add flowers and ornamental plants for interest and variety.

• Plant close to house so you don’t have to walk far.

• Select an area that gets 6 to 8 hours of sunshine daily.

• Stay clear of trees and shrubs where roots and shade interferes.

• The area should not puddle after a heavy rain.

E-mail the author of this story: yourlife@grpress.com