   Growing Green Beans - June 4, 2008 Jeff Schalau, Associate Agent, Agriculture & Natural Resources University of Arizona Cooperative Extension, Yavapai County Green beans are a home garden favorite ranking second to tomatoes in popularity nationwide. They are a warm season crop and should only be planted after soils have warmed up to 70 degrees F. A fairly good indicator of planting time in our area is to plant after the mesquite trees have leafed out. Once it warms up, green beans can be planted every two or three weeks through July. Your first decision is whether to plant pole or bush beans. Pole beans must climb up a trellis, fence, or other support structure they can twine around. The trellis should be 6-8 feet tall and sturdy enough to take wind. A teepee tripod support can be made with three wooden poles or large branches that are pushed well into the ground and wired together at the top. Popular pole bean varieties are Blue Lake, Kentucky Wonder, and Kentucky Blue. Even though seeds are self-pollinated, you should plant new seeds each year to avoid seed-borne diseases. Bush beans stand erect without support. Bush beans were formerly called "string beans" because fiber developed along the seams of the pods. Plant breeders have reduced these fibers through selection and bush beans are now sometimes referred to as "snap beans." Bush beans will also come into production about a week earlier than pole beans. Popular bush bean varieties are Bush Kentucky Wonder, Contender, Provider, and Tendercrop. French fillet beans are also bush beans with a unique flavor and are harvested when they are ¼ inch in diameter or less. Prepare the soil in a weed-free area as you would for other annual crops by tilling in composted organic matter and phosphorus fertilizer. As with other vegetable crops, rotate planting areas from year to year to minimize potential for soil-borne diseases. Bean seeds of all varieties should be planted one inch deep. Plant seeds of bush beans 2 to 4 inches apart in rows at least 18 to 24 inches apart. Plant seeds of pole beans 4 to 6 inches apart in rows 30 to 36 inches apart; or in hills (four to six seeds per hill) 30 inches apart, with 30 inches between rows. When using a tripod for support, 5-6 seeds are planted in a circle 6-8 inches from each pole. Seeds of most bean varieties tend to crack and germinate poorly if the soil's moisture content is too high. For this reason, never soak bean seed before planting. Instead water just after planting. Following germination, provide regular irrigation throughout the growing season. Since bean plants have fairly weak, shallow root systems, avoid deep, close cultivation. This can injure the plant roots, delay harvest and reduce yield. I also overplant and thin seedlings to compensate for potential pest problems. Harvest green beans when the pods are firm, crisp and fully elongated, but before the seed within the pod has developed significantly. Be careful not to break the stems or branches, which are brittle on most bean varieties. Regular harvesting of green beans will prolong flowering and increase yields. Beans have fewer pest and disease problems here in the west than they do in the midwest and further east. Our arid climate inhibits many fungal and bacterial diseases. I have had cutworm damage where seedlings are eaten off at soil level. This can be remedied by placing collars over newly germinated seeds (tin cans or yogurt containers with openings at both ends) and removing them when the plant gets two or more true leaves. Rabbits love green beans so plan on excluding them from your garden plot with fence. I have attached chicken wire 2 feet high to my woven wire fence with hog rings. This also prevents my chickens from eating the young plants through the fence. Woodrats (also called packrats) will climb fences. If you suspect them, you will probably need to use large rat snap traps and quite possibly other management approaches. I’ve been growing Kentucky Wonder pole beans for many years in my garden and always enjoy them throughout the summer. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at cottonwoodmg@yahoo.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/. |