no string beans #423073 - Ask Extension


no string beans #423073

Asked August 23, 2017, 6:35 PM EDT

I have very healthy string beans growing in my backyard very green and leafy and they have produced flowers. But no string beans! I'm wondering if it's a fertilization issue or what. Also I'm not getting a lot of production out of my zucchini plants

King County Washington

Expert Response

Thanks for your question about your string beans.  Here's an excerpt from an article by the WSU Extension service addressing this problem:

"Blossom Drop: Astute veggie gardeners have noted the lack of beans on their bean plants and attributed it to the heat. When temperatures climb well above 90 degrees, beans and peas will drop their flowers without setting fruit. The same often happens with tomatoes and peppers too. The reason for “blossom drop” and the lack of fruit involves pollination and the subsequent fertilization of the embryo in the ovary within the flower.

You might think the reason for this is that bees are not active in the garden when temperatures are above 100 degrees, but beans, peas, tomatoes, and peppers are self-pollinating and thus do not depend on bees or other insects to enable pollination and fertilization. However, these self-pollinating flowers do need wind or insects to shake the pollen from a male part of the flower (anther) onto a female part of the flower (stigma).

What about the veggies that do require an assist from bees and other pollinating insects? Fruit production of cucumbers, melons, and squash seems to slow in hot weather too. Aborted or misshapen fruit are because bees are not very active in the hot weather and because pollen does not remain viable for very long.

We can not do anything about the hot weather, but we can reduce plant stress and minimize cracking and blossom drop by keeping the garden soil evenly moist, mulching to cool the soil and conserve moisture, and not applying excessive amounts of nitrogen fertilizer. It’s also a good idea to provide bees with some moisture. Turn a bird bath or large pot saucer into a bee bath by filling it with coarse gravel or river rock and adding water. The stones are used as perches, so the bees will drown in the open water."

Hope this is helpful for you.  Good luck (next year)!

Kristena LaMar Replied September 06, 2017, 7:32 PM EDT

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