Pole green beans

Asked August 15, 2018, 3:11 PM EDT

I planted a row of pole green beans this year and the vines looked good. Bloomed and then never put on one bean, not one. What did i do wrong? They werent heavily fertilized. Normal watering. They where planted next to sweet corn and may have picked up fert off of them? Hope you can help.

Marshall County Kentucky

1 Response

Several conditions can contribute to poor yield in bean/legume plants. You mentioned two here:

1.) Legumes can develop a symbiotic relationship with nitrogen fixing bacteria in root nodules. Because nitrogen fixing supplies some of the plants N needs, beans and other legumes require less fertilizer than other vegetables. ID-128 recommends 2.5 oz. rate of 10-10-10 side dressed after a heavy bloom and set of pods. Heavy fertilizer application prior to flowering will promote vegetative vigor at the expense of flower development; plants will have a large, healthy canopy but no flowers/pods.

2.) Legumes are sensitive to soil moisture. Both waterlogging and drought stress can cause blossoms and small pods to abort. Low or poorly drained sites are subject to extended periods of soil waterlogging. Planting rows on a raised bed will promote drainage of excess water from around the roots. Drought stress will stunt plant growth and in legumes, slows or even stops the process of nitrogen fixation. Vegetables require 1-2 inches of rain per week for optimum growth and productivity. When rainfall is lacking, supplemental irrigation, most often by hand watering is beneficial.

Another: Blossom abortion in legumes and many other vegetable plants will occur in response to temperature extremes. In beans, optimum growth occurs between air temperatures of 70 to 80 degrees F. Pollination and pod set is adversely affected are less than 50 degrees at night or if the temperature exceeds 90 degrees during the blossoming period. Here in W KY we had a long stretch in June and July with temperatures in the upper 80’s and 90’s during the day and 70’s or near-70’s at night. Average highs and lows for these months were 87 and 67-68, respectively.

Now that the growing season is on the downhill slope and progressive, though punctuated, moderating weather is expected, it might be worthwhile to try a second crop of beans in the hopes of a better harvest.

Hope this helps.