Among garden bean plants (Phaseolus, Vicia and Vigna spp.), those from which we harvest undeveloped seedpods -- such as snap beans (Phaseolus vulgaris) -- generally can be picked about seven to nine weeks after planting. They are followed by types grown for their partially developed seeds, such as lima beans (Phaseolus lunatus), which begin producing within 10 to 12 weeks. Last come the plants that have been allowed to fully develop their seeds, such as dry beans (Phaseolus vulgaris), which generally take about 12 weeks to produce a crop. Growing beans is simple enough for even amateur gardeners.
Snap bean and dry bean cultivars actually derive from the same species. Therefore, if you don't get around to harvesting your snap bean pods while they are tender, you can let the pods mature and harvest dry beans from inside them instead.
Since beans don't transplant well, sow seeds directly in the garden in spring. Wait until after the danger of frost has passed, and the soil temperature has risen to at least 50 degrees Fahrenheit -- preferably to 60 degrees F. Fava beans (Vicia faba) are an exception to the rule in that they prefer cool conditions; start them in mid-spring in northern zones or in early autumn in U.S. Department of Agriculture plant hardiness zones higher than 7.
Things You'll Need
- Bean seeds
Spade or rototiller
Cattle panels, or 6- to 10-foot poles and plastic zip-ties
- Soaker hose or watering can
- Straw or grass clippings
Step 1: Prepare Site
Choose a location which receives at least 6 hours of sun per day, where beans haven't grown within the past three years. The ground should be only moderately fertile -- meaning, soil that hasn't been heavily treated with fertilizers or other high-nitrogen supplements. It also should be well-drained enough to crumble easily, with a pH between 6.0 and 6.8.
If your soil is heavy, spade or till 2 inches of compost into it. In addition to adding nutrients, compost can lighten the soil's texture and render it less crusty when wet.
Should the soil lack fertility, work a 5-10-10 fertilizer into its upper 6 inches, using 1 cup for each 50 feet of garden row.
Avoid using high nitrogen fertilizers, as they encourage foliage growth rather than pod formation.
Step 2: Space Properly
Once your bush bean seeds are a few inches tall, thin them by snipping off extra seedlings at the base -- preferably the weakest ones -- so that the remaining plants are spaced about 4 inches apart in rows 1 1/2 to 3 feet from each other. Climbing varieties can be planted 6 inches apart, in rows 3 to 4 feet from each other.
If you intend to grow the latter, you must provide a trellis or other support for them. Cattle panels (movable sections of fence) work well for this purpose, as do tripods constructed of three or four 6- to 10-foot poles secured together near their tips with zip-ties. If you use tripod supports, sow four beans in a circle around the bottom of each leg, removing the weakest plants to leave only two strong ones beside each leg.
Step 3: Water Beans
Keep the soil damp while the beans are germinating and make sure that they receive at least 1 inch of water each week afterwards, either from rainfall or irrigation. To prevent fungus diseases, use a method -- such as a soaker hose -- that provides moisture without splashing the plants' leaves. Alternatively, water them early enough that their foliage has time to dry before nightfall, and avoid working around the plants while they are wet, to prevent spreading fungus diseases from the leaves of one plant to another.
Step 4: Provide Mulch
When the beans have grown to the point that they each have four leaves in addition to their original two seed leaves, mulch them with 2 inches of straw or grass clippings to help retain moisture and suppress weeds.
If you can't apply mulch and must hoe the weeds instead, shave their stems off rather than hacking their roots up, as too-deep cultivation may damage the beans' shallow roots also.
Pole beans generally produce for longer than bush beans do. If you prefer the bush type, you may wish to sow new plants every two weeks until mid-summer to provide an extended crop.