Beans are not only easy to grow in the home garden. They are also one of the most versatile vegetables in the kitchen. Depending on the variety you select, beans can be enjoyed pod and all as snap beans, or out of the pod as tender shell beans. Left to dry on the vine, beans store well and provide nutritious eating all winter long. If you're short on space or looking for ease of harvesting, pole beans grown on vertical supports fill the bill. Quick maturing bush beans are easy to sow and grow, and their more concentrated bearing period works well if you plan to can or freeze your bounty.
Besides their delicious taste, beans are nutritious additions to a healthy diet. Fresh green snap beans are a good source of fiber and Vitamins A, C, and K. Dried beans are high in protein, fiber, and folate, and are a good source of Vitamin K, iron, and other minerals.
There are several types of bush beans, but all produce plants that grow 2 feet tall or less. The snap bean varieties with round green pods are probably the most familiar, but there are also some with flattened pods. For the most reliable germination when soil is still on the cool side, choose varieties with dark colored seeds. Prolific bearers, bush beans 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. Some bush bean varieties are grown primarily for use as fresh shell beans or for drying. Yellow wax bush 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. Warmth loving lima beans are available in bush and pole varieties.
Many folks think that pole bean varieties have the best, "beaniest" flavor of all. Their tall vines 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 than with bush bean plants. This makes them a good choice for gardeners who grow beans mainly for fresh eating. Both limas and snap beans are available in pole bean varieties. Pole beans need sturdy poles or a trellis to support their vigorous growth.
For even more variety, there are other members of the bean clan to explore, including nutritious soybeans and Asian yard long beans that do best in climates with warm days and nights.
Tips for Growing Beans
Wait for Warm Weather
Bean plants don't transplant well, so seeds should be planted directly in the garden where they are to grow. But don't rush your bean planting. Bean seeds planted in soil below 60 F will often rot before they germinate, and the seedlings won't tolerate frost. Wait until the danger of frost is past and your soil is warm and dry before tucking those seeds into the ground. Raised beds are a good choice for bush beans because the soil in them dries and warms soonest. Varieties with dark colored seeds germinate better in cool soil than white seeded varieties.
Pole beans are even more demanding of warm soil than bush beans. They like it to be at least 65 F, so plant them about a week after you make your first bush bean planting or about a week after the last frost date for your area.
Bolster Beneficial Bacteria
Beans are legumes, plants that host a beneficial type of bacteria called Rhizobia in nodules on their roots. These bacteria take up or "fix" nitrogen (an essential plant nutrient) from the air, where it's in a form that's not available to plants, and change it into one that plants can take up and use. This also benefits you as a gardener because you don't need to worry about adding extra nitrogen to the soil in the form of fertilizer for your beans when the bacteria are hard at work.
If you are planting beans for the first time in your garden, you may want to mix your seeds with a purchased inoculant powder (available from a garden store) to make sure these helpful bacteria are present in the soil. But once they've been introduced into your garden, they generally become established and don't need to be added yearly.
Plant Bush Beans in Succession
Make successive small plantings of bush beans every 2-3 weeks until about two months before your fall frost date for a continuous harvest all summer long. As individual plants finish bearing, pull them up and add them to your compost pile (as long as they are disease-free).
Look Out for Insects and Disease
Beans are generally a pretty trouble-free crop. But there are some pests and disease problems to keep an eye out for.
One of the most common insect pests is the Mexican bean beetle, found in most parts of the country. This pest looks something like a ladybug, but it's definitely not beneficial! The 2-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 or azadirachtin 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.
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. 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 keep these diseases to a minimum, plant in well-drained soil, avoid overhead watering or water early in the day so plants dry quickly, and space plants widely to encourage good air circulation. Avoid working in bean patch when the leaves are wet to prevent spreading diseases from pla nt to plant. Remove infected plants and clean up and dispose of plant debris at the end of the season. If you can, plant beans in a different location of the garden each year; use a 3-year rotation if you can.
Bush and pole beans are ready to harvest when their pods are firm and crisp, about the size of a pencil in diameter, and the seeds within the pods are still undeveloped or just barely visible as small bumps in the pod. Pick filet beans when they are still very slender, only 1/8" to 1/4" in diameter. Plants are somewhat brittle, so pick carefully -- hold the vine in one hand and pull off the pod with the other to avoid breaking the stems. Pick often -- the more you pick, the more the plant will produce.
Q: Last year in the middle of the summer, the flowers on my bean plants fell off without forming pods. Later on, the problem corrected itself and the bean plants began bearing again. What was going on?
A: The pollination of bean flowers can be affected by temperatures that are too high or too low. Temperatures that reach over 90 F can cause blossoms to drop before pods to form. At the other end of the spectrum, temperatures below 60 F during the day or 40 F at night can cause misshapen or incompletely filled pods. Once temperatures moderate the beans will resume bearing again. Moisture stress can also cause bean plants to drop blossoms, so try to keep soil moisture consistent. An organic mulch such as straw put down after the seedlings have come up will help to retain soil moisture and keep weeds down.