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Why Didn't My Summer Squash Plant Produce Squash?

My summer squash never really developed – the squash turned yellow and fell off. What went wrong?

Answer: Summer squash and zucchini come in a variety of shapes, colors and tantalizing flavor, perfect for salads, dips or cooked recipes. They're known for an easy and prolific harvest. So what could cause the squash to not fully develop?


Failing summer squash plants could be caused by a number of issues: improper watering, poor soil or intruding pests such as squash bugs, cucumber beetles and/or vine borers. Inspect stems and leaves for signs of insect damage to rule that out. Be sure your plants are in a spot to receive eight hours of sun each day, and that you haven't applied a high-nitrogen fertilizer that will promote leafy growth over the formation of flowers and fruit.

However, sometimes you could have perfectly healthy plants with no signs of trouble. When plants are thriving but fruit isn’t being produced, it could be due to female flowers not being pollinated. Summer squash need insects, like bees, to pass the pollen from the male flowers to the female flowers. If there are not enough pollinators, or they don't find your plant, it will not produce sufficient fruit. You may get some fruit set, but it will be small or deformed and it will not develop to harvestable size or quality.

If your yard is lacking a bunch of buzzing bees to help your plants into production, you can pollinate your summer squash or zucchini. Use a cotton swab or small paintbrush to take the pollen from the male flower and transfer it to the female flower. Distinguishing from the two flowers is relatively easy. Male flowers have longer straight stems, while females will have a bulge just below the flower petals.

Once you have identified the two flowers and have successfully transported the pollen, your female flowers should begin to produce healthy, delicious veggies for you to harvest. While these develop, spend some time planning companion plantings of showy ornamental flowers and other features that will draw pollinating insects' attention to your vegetable patch.

Image credit: USFWS Midwest Region/Public Domain