On Gardening/Growing Better Garden Beans

6-2-97
University Park, Pa. -- Beans of many varieties are popular and easy to grow garden plants. The edible portion of these plants are high in protein, fiber and other essential vitamins and minerals. The fact that they grow well in most areas of Pennsylvanian makes them a good choice for home gardeners.

For best growth and survival, make certain the soil has warmed and all danger of frost has passed before sowing bean seed. Late May or early June is still the best time to start a bean crop in all but our southern most counties where slightly earlier planting is possible. The site should be as sunny as possible and the soil should be fertile and well-drained. Be careful not to add too much nitrogen fertilizer because this will cause all top growth and little flowering and fruiting. Remember that the beans we eat are actually the fruit.

Like peas, beans can be planted in double rows to increase yield and get the best use of garden space. Plants in double rows support each other as they mature. Bush cultivars should be seeded in rows 9 to 12 inches apart with 18 to 24 inches between the paired rows. Leave 2 inches between plants in the row.

Pole beans can also be sown in double rows 12 inches apart with 36 inches between paired rows. Thin these plants to about 3 to 4 inches between plants. Any variety of supports can be provided for the beans. Some of the newer plastic or cotton netting can be used or fence or chicken wire also works well.

Once the seeds have been sown, keep the soil surface from crusting over. Crusting retards seedling emergence and often results in damaged plants as they try to break through the hard soil. A newspaper mulch over the soil helps prevent compaction and crusting from the light showers so common at this time of year. Once the seedling break through the surface remove the paper.

We often get questions about when various types of beans should be harvested. Snap beans, both green and wax are probably the most commonly grown beans. These should be picked just as the seeds begin to show enlargements in the pods. Today, most cultivars are stringless, but the pods become increasingly fibrous and tough with age. I think that once the seed inside the pods begins to color or darken the beans are past their prime quality. The 'Romano' bean is a broad snap bean and also falls into this group.

The other two categories of beans include green-shell and dry-shell beans. Fruit on these types is allowed to mature until the inner seed in the fruit approaches or reaches maturity.

Lima beans are the best known green-shell bean. These are harvested when the pods and seeds are fully developed but still bright green. The beans can be easily removed from the pods and cooked. Some snap beans can be harvested as green-shell. Other popular types like the broad bean, scarlet runner bean or yard long bean can also be harvest as green-shell.

Dry-shell beans are those which are left on the plant until full maturity and are quite dry. The navy bean is probably our best known dry-shell bean. However, any cultivar of navy, kidney, snap, lima, broad or scarlet runner bean can be left to mature for use as dry-shell beans.

Most cultivars of snap beans can be sown in the garden up to the middle of July in most Pennsylvania counties and still set some fruit before frost. Hot, dry summer weather, however, may take a toll on flowers and subsequent fruiting, but your should obtain enough beans to make a second sowing worth the effort.

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*Dr. Nuss is a horticulturist at Penn State. He coordinates all extension horticulture programs. He has bachelor's, master's, and doctoral degrees in ornamental horticulture and has been on the Penn State faculty since 1966.