A Bounty of Beans
If easy gratification in the garden is what you're after, beans are a pretty good place to start. Easy to sow and grow, adaptable and usually problem-free, beans produce in abundance for very little effort. In fact your biggest problem is likely to be what to do with all the beans you've grown.
There is a bean for just about every garden situation and palate. Bush beans produce large crops of beans that are ready for harvest quickly and can be planted in successive sowings so you have plenty of tender pods throughout the season. Tall growing pole beans produce over a long season and are renowned for their delicious "beany" flavor. For the adventurous there are novelty types such as aptly-named yard long beans.
There are several types of bush beans, but all produce plants that grow 2 feet tall or less. The varieties with round green pods are probably the most familiar. They germinate reliably, even when the soil is still on the cool side, their sturdy seedlings shouldering their way through the soil toward the light. Prolific bearers, they are great for fresh use. Because they ripen their pods in a fairly short period of time, they work well for folks who want to can or freeze their crop. Yellow wax beans add a beautiful color to the garden or the dinner plate. The slender French or filet beans have a delicate flavor and texture that more than makes up for their their less abundant bearing.
You'll need to wait slightly longer to start harvesting from pole beans, but they are worth the wait. Many folks think that pole beans have the best, most pronounced "bean" flavor of all. Their tall vines will produce more beans in total over a season and for a longer period of time, but the harvest at any one time will be smaller. This makes them a good choice for gardeners who grow beans mainly for fresh eating. Pole beans need sturdy poles or a trellis to support their vigorous growth.
Adventurous gardeners may want to explore other members of the bean clan. Shell and dried beans are harvested when the seeds have matured inside the pod, but the pod is still green (shell beans) or dried. Shell beans are tasty steamed; dried beans are great baked or in soups.
Like their cousins, the peas, beans are members of the legume family. This means that, with the help of specialized bacteria (Rhizobium) in the soil, beans can take up and use nitrogen from the air. So you don't need to worry about adding extra nitrogen to the soil for your bean crop. In fact, the beans will leave your soil more fertile than they found it! If you are planting beans or peas for the first time in your garden, you may want to mix your seeds with a purchased inoculant powder to make sure these helpful bacteria are present. But once they've been introduced, they become established and don't need to be added yearly.
Beans do need well-drained soil and will benefit from a 2 to 3-inch layer of compost or composted manure worked into the soil before planting. If your soil is low in fertility, you can add a low-nitrogen fertilizer such as 5-10-10 to boost phosphorus and potassium levels.
Don't rush your bean planting. Bean seeds planted in soil below 60 F will often rot before they germinate. So wait until your soil is warm and dry before tucking in those seeds. Raised beds are a good choice for bush beans because the soil in them dries and warms soonest. Pole beans are more demanding of warm soil- they like it to be at least 65 F, so plant them about a week after you make your first bush bean planting. Make successive small plantings of bush beans every week or so until midsummer for a season long harvest.
Plant bush beans in rows 1-2 feet apart, spacing the seeds 1 inch apart and 1-2 inches deep; thin plants to 4-6 inches when they are a couple of inches tall. Pole beans climb by twining and need a 6-8 foot tall fence, trellis or pole to clamber up. Plant their seeds 1-2 inches deep at the base of the support. If you are using poles for support, place 4-6 seeds in a circle about 6 inches out from the base of the pole; thin to one or two of the strongest plants per pole.
Caring for Your Beans
Beans are generally a pretty trouble-free crop. They will do best if they don't have to compete with weeds and have consistent moisture. A mulch such a straw put down after the seedlings have come up will help to retain soil moisture and keep weeds down. The pollination of bean flowers can be affected by temperatures that are too high or too low. If it gets below 60F during the day or 40 F at night, the developing beans in the pods may abort, giving you pods that are misshapen or incompletely filled. And temperatures over 90 F can cause blossoms to drop and no pods to form. Once these problematic temperatures pass, the beans will resume bearing.
Beans are susceptible to a number of bacterial and fungal diseases. Bacterial blights cause small, water-soaked spots on the leaves that enlarge, turn brown and can eventually kill the leaf. Lesions may also appear on stems and pods. Common blight can be a problem east of the Rockies, especially when the weather is hot and humid. Halo blight is more of a problem when the weather is cool. You can keep these diseases to a minimum with good garden sanitation. Remove infected plants and clean up or bury plant debris at the end of the season, try to have a 3-year rotation for the location of bean plants in the garden and avoid working in bean patch when the leaves are wet. White mold is a fungal disease that causes water-soaked spots on leaves, stems and pods. When the weather is moist, a fuzzy white mold forms on these spots. You may see what look like small, black, seeds in the mold. To control white mold, plant in well-drained soil, avoid overhead watering or water early in the day so plants dry quickly, space plants widely to encourage good air circulation and rotate crops. A fungicide can be used if the problem is severe, but it will not cure the disease, only prevent its spread.
The Mexican bean beetle is found in most parts of the country. This pest looks something like a ladybug, but it's definitely not beneficial! The 1/4-inch long, reddish adult beetles have 16 black spots on their backs; the orange-yellow, soft-bodied, spiny grubs also dine on bean leaves. The tissue between the veins will be eaten, giving the leaves a lacy appearance. Adults overwinter in plant debris, so clean up the garden well at the end of the season. Look for and squash yellow eggs on the undersides of leaves. Handpicking adults will often control the problem. Pyrethrin sprays can be used for a more serious infestation; be sure to spray the undersides of the leaves where these pests feed. Floating row covers can prevent damage to young plants, but you'll need to remove them once plants begin to flower so pollinators can reach the blossoms.
Bush and pole beans are ready to pick when their pods are firm and crisp, but the seeds within the pods are still undeveloped. Harvest by holding the bean stem in one hand and carefully pulling off the individual beans with the other. Pick often- the more you pick, the more the plant will produce. Shell beans are ready when the pods are full and green. Let your dry beans mature on the vine until the pods dry begin to split.
Question of the Month: Leafless Bean Seedlings
Q. My bean seedlings came up quickly, but without any leaves. What's wrong?
A. This is a condition called bald heading. Sometimes it happens when insects in the soil damage the seeds, but it can also occur when seeds are planted too deep, especially in heavy soil. The young leaves are ripped off as the seedling pushes its way through the heavy soil. To prevent this problem, make sure your seedbed is well prepared, with rocks and large clods of soil removed. Plant seeds on the shallow side (1 inch deep), especially if your soil is heavy. If you do get leafless seedlings emerging, pull them up and replant, since these damaged seedlings won't produce.