I was wondering if zucchini needs to be hand pollinated. Do zucchini grow better when hand pollinated. How long does female flowers open? What time of the day do they start to open? Would you share any tips in terms of pollination?
Hello and thanks for writing TMG with your questions. Zucchini does not necessarily need to be hand pollinated but if you are not getting very many mature fruits or your zucchini plants drop their blossoms before setting fruit or the new fruit dries up before maturing, then hand pollination will improve fruit set.
Blossoms drop differently, depending on whether they’re a male or female flower. Male flowers drop when they shed their pollen; female flowers drop if they’re not pollinated. Early in the season, zucchini (and other plants like cucumbers) may produce a dozen or more blooms, but these are usually the male flowers, the ones with the pollen, Without female flowers, there isn’t a need for the pollen. Sometimes female flowers bloom before the male flowers, so there’s no pollen available. Without pollination, the female flowers will dry up and fall off. Weather plays a role in pollination, too. If the weather isn’t dry and warm enough, bees might not be around to help move pollen from the male flowers to the female flowers. Other reasons for plants dropping their blossoms include too little or too much water and poor soil conditions.
You should do the hand pollination early in the morning when the most pollen is available and the flowers are wide open; they start to close up later in the day. Female flowers are only open for one day, so you need to check your plants daily. Male flowers are the ones with short stems while female flowers have longer stems and a tiny zucchini fruit at their base.
This link gives an excellent and detailed explanation, along with good pictures, of how to hand pollinate zucchini and cucumbers and other squashes.