Knowledgebase
Zucchini female flowers turn yellow and stop development before they open #655863
Asked June 25, 2020, 11:00 AM EDT
Hi! My zucchini plant has had fruit and healthy male and female flowers. But recently, the female flowers have turned yellow, they stay small and don't open. The female blossom development is stunted, while the male flowers continue to normally grow and open. How can I prevent this to happen?
I have attached a picture that shows a yellowed stunted flower on the left and a healthy growing flower on the right. The other picture shows one of the unopened flowers that ended up wilted, so I removed it.
County Michigan
Expert Response
The first flowers to appear on a zucchini plant are the male flowers and the female flowers may not come for a week or more afterwards. Female flowers have a tiny fruit attached to their base, so they are easy to distinguish from the male flowers. You need both to be blooming at the same time to get fruit. Now the other needed ingredient are insects to pollinate them. Flowers that are not pollinated or not well pollinated will fall off. Misshapen fruit also indicates low pollination. Since the flowers are only open and fertile for a short period of time you may want to consider hand pollinating them. You can pick the open male flowers and shake the pollen off over an open female flower. You could also transfer pollen from one flower to another with a q tip. Also be sure that you do not let your zucchini plants ‘stall’. Be sure to fertilize them when planting starts and to keep them evenly moist. Give them a boost with a liquid fertilizer if they are not developing as expected. They are warm weather vegetables so do not put them out too soon. Consider putting drip irrigation down and covering the ground under the plants with black plastic. This will keep the soil warm and hopefully your zucchini happy.
An article from the University of Maryland explains some more information on squash. The link is here: https://extension.umd.edu/hgic/topics/summer-squash
Of course, you could plant two plants to ensure ample blooms of both types are available for the pollinators. The excess fruit can be shared with a food bank or the neighbors.
Happy gardening.
I understand the information you presented and my issue is not pollination since I have been manually pollinating the flowers that did open in the past. My issue specifically refers to female flowers not opening and turning yellow and wilting when they are still small.
do you know how I can avoid that from happening?
I hope this helps,
