Green Beans

Phaseolus vulgaris
by Master Gardener Cathy Brooke

Green beans are a summer veggie garden staple. And why not? They are easy to grow, attractive, tasty, provide a vegetarian source of protein, and are nitrogen-fixers which helps your soil. They do need warm weather to thrive, so don’t be discouraged if they aren’t as big as you hoped for by now. They also will need to be picked to keep producing. So, once they get started, don’t hesitate to pick hard and often. Check them every two to three days during peak harvest season; you may be surprised how quickly they go from being too small to just right.

Beans are available in bush, half-runner or pole variety. Most of us are accustomed to the pole variety, including the ever-popular ‘Blue Lake.’ I have never planted any variety except pole beans, although, taking lower-water use gardening into consideration, I soon may try a bush variety. Bush beans typically mature early, which requires less water to reach harvest, and do not require trellising. Pole beans, on the other hand, are natural climbers and require support. Sturdy wooden poles, six- to eight-feet tall, tied together at the top and placed in the shape of a teepee, offer good support. Plant one or two seeds a few inches from the base of each pole.  Half-runner beans have a growth habit between that of bush and pole beans and generally are grown like bush beans. Trellising, however, may increase production.

There still is time to plant beans in Sonoma County – pole beans can be planted May through July; bush beans through September. Beans grow well from seed, sprouting in about 7 to 14 days, depending on the variety and weather. Planting can be staggered for a continuous harvest through the season.

I am trying a new technique this year for our pole beans, and have formed an arbor of hog wire with ‘Scarlet Empire’ and ‘Blue Lake’ beans planted on either side. I’m hoping to be able to stand under the arbor to harvest the beans in the shade! We previously grew scarlet runner beans which produced lovely red blossoms that attract hummingbirds as well as delicious beans that can be eaten fresh or grown to full maturity and dried.

If you are concerned about water use in a drought year, consult the watering guidelines for food gardening  prepared by the Sonoma County Master Gardener Food Garden Specialists in consultation with UCCE. Because there is not enough water to irrigate deeply in a drought, gardeners are advised to water more often, not allowing the active root zone to dry out. This practice assumes that, once seeds sprout, you are using three to four inches of mulch on top of the soil to keep the soil cool and inhibit weeds, making more stored water available to food crops. There are a number of drought-tolerant varieties of beans  including ‘White Half Runner Snap’ bush beans and ‘Garden of Eden’ Romano beans, a large flat variety. Beans, even drought-tolerant varieties, need water most when they are blooming and setting fruit. Light, even water is sufficient prior to that time.

One little known fact about beans: in Europe, a folk remedy for bedbugs is to strew bean leaves on the floor next to beds. The microscopic hooked hairs on the backs of the bean leaves, known botanically as trichomes, ensnare and impale the legs of the blood-seeking parasites on their nightly forays. The bug-encrusted greenery was burned the next morning to exterminate the insects. University researchers, including some at the University of California/Irvine, have studied this physical entrapment mechanism hoping to find new ways to trap bed bugs.?
During peak harvest time, you may think that you’ve run out of ways to eat beans. Small, thin beans are fabulous blanched and tossed into a salad with thinly sliced grilled beef and a vinaigrette dressing. One of our favorite ways with green beans is to blanch them and toss with pressed garlic, lemon juice, a dash or two of hot sauce, and a drizzle of olive oil or a pat of butter. Don’t forget, you can always let them grow big, shelling and drying them thoroughly, for use in the fall and winter as dried beans.

And, lastly, remember beans’ ability to add nitrogen back into the soil. Leafy greens and plants in the cabbage family are heavy nitrogen feeders. When planting the fall/winter garden, consider planting these heavy feeders where beans are grown this summer.