“Why does butternut squash start to rot before it gets bigger?”
Or, “Why do I have lots of flowers on the zucchini plant, but never fruit?”
These are the questions that bother gardeners every summer, and are often blamed for irrigation, pests, or disease, when in fact bees (or insecticides that prevent them from coming).
Why?
As you know, squash plants can be found in grape grapes and female blossoms (plant terminology, called monogenous plants), which appear at different times.
In squash heirloom breeds, men usually appear first and grow abundantly at the end of a long, thin stem. Women usually appear first on hybrid breed squash, but this can all be weather dependent.
Long and warm nights tend to prefer male flowers, while short and cool nights prefer female flowers. So there will be more male flowers at the beginning of the season, a balanced mix of midsummers, and gradually more female flowers as the season ends.
Female flowers usually appear one or two weeks after males, grow low on the ground and approach vines.
If the ovaries are not pollinated when the female flower opens in the morning, the flower will close that night, start to wither, and eventually fall from the vine in a few days. This means that even if it looks promising at first, squash won’t come.
And yes, that means that women’s flowers are open only for one day, so all the stars need to be aligned for those flowers to be properly pollinated!
If a bee (or other pollinator) happens to come that morning, you hope it does a good job of spreading the pollen and getting squash. For six visits from squashbee and only two visits from the highly efficient Bumblebee, up to 15 bee visits are required to achieve pollination.
The bees land with open male flowers to collect nectals, and in all their activities they happen to collect pollen in their bodies. When they fuss around the plants, keep busy, and do what the bees are doing, they land in open female flowers and unintentionally transfer pollen to it.
that’s right. The next meal will depend entirely on these little creatures to find your squash flowers among the thousands of other flowers in the neighborhood, and will unconsciously fertilize them.
If there is not enough pollen to pollinate a female flower, the ovaries of that flower will not be fertilized. This is more reason to attract as many bees as possible to pollinate your female flowers and turn them into squashes, so this is the best way to attract as many bees as possible to your garden with beneficial and nectar-rich plants.
If bees are low activity, some gardeners will take an extra step to help them hand over their hands to paint the flowers.
Even if you have healthy bee populations in your garden, you can still try pollinating some flowers just to increase your overall yield. You may be surprised how many flowers are not naturally pollinated!
How to pollinate squash by hand
First, get to know the anatomy of squash blossoms.
On male flowers, the stamens are centrally reproductive structures, consisting of annthers (pollen producers) supported by thin filaments. This phlice is covered with yellow pollen grains.
On female flowers, the pistil is an ovule-producing structure, consisting of ovaries (immature fruits) that support long styles topped with stigma (a sticky orange structure in the middle). This adhesiveness helps pollen to adhere to it.
Male flowers grow on tall, thin stems, female flowers grow near grapes, with immature fruits on the base.
During hand pollination you simply mimic the bees by the bees collecting from annther and depositing them into the stigma. Yes, it’s as easy as it looks!
The ideal time to pollinate squash is in the morning as soon as the squash blossoms open (and temperatures are mild). They tend to close by the evening, so if you want to get to all of them, you might spend a few days manually.
Hand pollination method #1: Choose male flowers.
Identify male flowers in the squash plant and make sure they are fully open. Otherwise, make sure the pollen is not ripe. (When you rub the other with your fingertips and the grains are not coming off, you will notice that the pollen is not ripe.) Choose a male flower. You will use it as your “tool” to fertilize the female flowers. Peel (or peel) the petals to reveal the anther. Gently rub the anther over the surface of the stigma (of female flowers) until it is fully pollinated. Work quickly as pollen can only survive for a few minutes after it is taken from the other. Repeat with as many male flowers as needed to pollinate all female flowers.
Hand Pollination Method #2: Use a paint brush.
Using a soft, small paintbrush lightly polish the male flower onp until the hair is covered in pollen. I polish the stigma of women’s flowers several times (as if I was drawing a picture). Collect more pollen from other male flowers with a paintbrush and continue the “painting” stigma until all female flowers are pollinated.
Some people use Q-Tip or other cotton swabs to handwrite, but personal experience has shown that much of the pollen sticks to the fiber (not that much pollen moves into stigma).
If pollination is successful, you can know in 2-3 days, and it becomes an almost certain bet with hand pollination – the eggs will swell and begin to mature into fruits with seeds. And within a few weeks, you can harvest that squash!
If pollination is not done, it will block rotten fruit. It will not develop into anything. What you leave on the vine is the plant’s energy drain (not to mention landing pads for pests).
What about male flowers? Well, if they are not harvested for food or chosen for hand pollination, they open and die immediately. So don’t waste them!
Related: The top and tails of these vegetables are edible – and you didn’t know that
Why pollination fails
Hand pollination is almost always successful, but some things can hinder your efforts. Proper pollination depends on good pollen, and good pollen depends on temperature, sunlight, hormones, and plant maturation.
Daily temperatures too high can affect pollen quality (even sterilizing). Squash is a warm weather crop, but extreme heat (evenings when extraordinary daytime rain does not fall below 90°F or 70°F) can reduce pollen survival.
Consistently hot weather may mean many male flowers, but women’s flowers are much less (and less likely to get fruit).
Heavy rain and excessive overhead watering can also reduce the amount of pollen available. This can reduce the good reason to water plants more efficiently by choosing dripping irrigation with plant beds or dipping hoses. If you need to water by hand, just water the soil (not flowers) and do not water the woman’s flowers when they open. I don’t want to discourage pollinators from visiting!
What to do next in your squash harvest:
This post was updated from an article originally appeared on July 16, 2014.
