CORVALLIS - Green beans are a favorite in many Oregon home gardens. And for many years, they have been a focus of work by the Oregon State University vegetable breeding program.
Early research by OSU plant breeders Tex Frazier and Jim Baggett resulted in bush beans that were bred to save the cost of putting up trellises and to allow mechanical harvest.
OSU's Jim Myers continues to develop even better beans. As the OSU Baggett-Frazier Professor of Vegetable Breeding, Myers is working on developing bush blue lake beans with a more upright plant architecture and resistance to white and gray mold. Upright plants hold their pods off the ground, reducing spoilage from diseases such as white mold, and allowing a more efficient harvest.
White and gray molds are our most significant diseases of beans in western Oregon, but it is difficult to breed for their resistance. Our best sources of resistance are another species of bean, called the scarlet runner bean. Transferring resistance from scarlet runners into green beans is a long, slow process.
Homegrown green beans, whether pole or bush types, are crisper and more flavorful than their supermarket counterparts. And they are easy to grow.
Plant bean seeds when the soil temperature is at least 60 degrees. This often means the end of May in the Willamette Valley. Seeds will germinate in cooler soil, but they tend to crack, which invites unwanted microbes. White-colored bean seeds are particularly sensitive to cracking, according to Myers, so he recommends planting colored bean seeds such as brown-seeded 'Kentucky Wonder' if you are planting in cooler soil.
Plant bush bean seeds two to three inches apart and one inch deep in a sunny, well-drained area. Pole beans should be planted like bush beans, except they must be supported by trellises or poles. Green beans are ready to harvest about three weeks after flowering. Keep plants picked for more production.
Beans are subject to several viruses, root disorders and molds. To keep your plants healthy, avoid overhead watering that wets the leaves, remove dead plants at the end of the year and rotate your crops from year to year.
The OSU Extension Service recommends the following varieties of bush beans: Oregon Trail, Tendercrop, Blue Lake Venture, Slenderette, Minuette and Oregon 91G. East of the Cascades grow Hystyle, Probe, Shade, Slenderette and Jade. Roma II is an excellent Roma-type bush bean.
OSU-recommended pole beans include: Blue Lake, Kentucky Wonder, Romano, Cascade Giant and Kentucky Blue.