The U.S. Department of Agriculture cites a figure of 420.1 pounds for U.S. per-capita vegetable consumption in 2008 and gives the figures in the table below for per-capita use, in pounds (farm weight), of selected commercially produced fresh and processed vegetables and melons for that year. (See ers.usda.gov/Publications/vgs/VGSTables.htm.)

This figure suggests that a gardener who grows about 400 pounds of produce can meet average consumption levels from his or her own backyard — especially if the gardener avoids unhealthy uses of some vegetables, such as potato chips (16 pounds’ worth of potatoes per person in 2007, according to the USDA) and french fries (presumably a significant part of the 53 pounds per person of frozen potatoes consumed in 2008).

Can you grow 400 pounds of vegetables? On his Kitchen Gardeners International Web site, southern Maine gardener Roger Doiron estimates that in 2008, he grew 834 pounds of vegetables (and strawberries, basil …) for a total value of $2,431 (based on the cost of the same organic produce at the farmers market; and including costs of $282) in his 1,600-square-foot garden, reaping about $1.50 per square foot. (See kitchengardeners.org/2009/03/whats_a_home_garden_worth.html.)

That may not be enough to feed his family of five, but it puts a good dent in the food budget —- and is a good way to exercise and get your daily dose of vitamin D from the sun.

Different planting methods will give different yields. According to Pete Lane of Ohio State University (http://ohioline.osu.edu/hyg-fact/1000/1641.html), a traditional home garden under good management may yield about 0.6 pounds of vegetables per square foot, but three years of production records from a raised bed at Dawes Arboretum near Newark, Ohio, indicate an average of 1.24 pounds per square foot, more than double the conventional yield.

“Raised beds do not require the usual space between rows because no walking is done in the bed to cultivate or harvest,” writes Lane. “Hence, vegetables are planted in beds at higher densities — ideally spaced just far enough apart to avoid crowding but close enough to shade weeds.” Because no one walks on the beds, the soil is not compacted. “Soil compaction can reduce crop yields up to 50 percent,” says Lane.

Use these figures (and the table of yields per 100-foot row on page 3 of the Johnny’s Selected Seeds catalog) as guides to help plan how much of each crop to plant in your own vegetable garden, adjusting the amounts depending on your likes and dislikes. With good soil and close planting, you might estimate a conservative yield of about 1 pound per square foot. So in a 400-square-foot garden — just 20 by 20 feet — you can grow enough veggies for yourself.

Artichokes (f) 1.6

Asparagus 1.5

Beans, snap 7.5

Beans, lima 0.3

Beans, dry 6.3

Beets (c) 0.5

Broccoli 8.6

Brussels sprouts (f) 0.3

Cabbage 8.2

Carrots 10.6

Cauliflower 2.1

Celery 6.2

Collards (f) 0.4

Sweet corn 24.4

Cucumbers 10.3

Watermelons 15.5

Cantaloupe 8.9

Honeydew 1.7

Eggplant (f) 0.9

Endive, escarole (f) 0.2

Garlic 2.8

Greens, mustard (f) 0.3

Greens, turnip (f) 0.3

Kale (f) 0.2

Lettuce 28.0

Okra (f) 0.5

Onions 21.7

Peas, green 2.9

Peas and lentils, dry 0.7

Bell peppers 16.0

Pumpkin (f) 4.9

Radishes (f) 0.5

Spinach 2.5

Squash (f) 4.2

Tomatoes, fresh 18.5

Tomatoes, canned 67.2

Potatoes, fresh 37.9

Potatoes, processed 80.8

Sweet potatoes 5.0

Mushrooms 3.6

Total 420.1

(f) fresh

(c) canned