"How to Grow",  Beginner Basics,  Flowers

Squash Sex: How to Hand Pollinate Squash to Prevent End Rot & Increase Yields

Have you ever tried to grow squash, but then much to your dismay, the promising little squash rots and falls off instead of getting larger? Well… that is most likely due to a lack of pollination! But don’t worry! There is a very easy solution. It has to do with “the birds and the bees” ~ or a lack thereof!


If you hope to have big healthy zucchini this summer, read along to learn all about hand pollination! Let’s explore the difference between male and female flowers, and exactly why, when and how to hand pollinate your squash plants. Check out the video at the end of this post to watch me pollinate ours!

A photo of large zucchini plant in a wood raised bed. There are large zucchini fruit hanging down over the edge of the planter box. In the background are a variety of large plants with flowers, out of focus. The raised bed is surrounded with blue-green gravel and stepping stones.
Many people wonder about the pattern on the leaves. No, that isn’t mildew or disease, though it does look similar! Many squash and melon varieties have a natural variegated leaf pattern. This Dunja zucchini is actually naturally resistant to powdery mildew! Mildew will usually look a little less uniform, more raised and fuzzy, and start on the underside of the leaves first.

Why Hand Pollinate Squash?


When a female squash blossom goes unpollinated, the small attached fruit will fail to thrive and develop. It will stay stunted, start to rot from the flower end, and eventually die and fall off. Therefore, if you want to ensure your plants produce edible fruit for you to enjoy, hand pollination can vastly increase their success – and your yields!

This idea applies to summer squash, like zucchini or crookneck squash, as well as winter squash like butternut, pumpkins, or acorn squash.

If you live in a place that has a robust, healthy bee population, you may not find the need to do this. Unfortunately, that is not the case in most places. Even here in our garden, which is bursting with pollinator-friendly plants and buzzing with bees, we find that some squash still fall off due to lack of pollination on occasion! So I still routinely hand-pollinate. I mean, why not guarantee success?

For a list of plants that will help attract pollinators to your garden check out our “Top 23 Plants for Pollinators” article!

Male vs Female Squash Blossoms


The first thing you need to know if you want to hand pollinate squash is how to tell the difference between the male and female flowers. And, each of their roles in pollination and fruit development! As with many things in this world, both a male and female are needed to create new life.

A female squash blossom is most easily identified by the little immature squash fruit that is attached at the base of the flower. Additionally, if you peek inside the flower, the inner bits are more round and curvaceous. That is called her stigma.

On the contrary, a male squash blossom lacks any sort of fruit. Instead, it has a straight plain stem at the end of the flower. Inside is his anther – an appendage with a pollen-covered tip. See the images below.

Three photos showing the difference between male and female squash blossoms. One shows a male, with a straight pollen covered anther inside the blossom. The female shows a more bulbous stigma part inside. At the base of the male is a straight stem. The female flower has a small immature zucchini.

How to Hand Pollinate Squash


In order to hand-pollinate squash, all you need to do is transfer some pollen from the male flower’s anther onto the female flower’s stigma. It is really as easy as that! Let’s go over a few pointers though.

You can use a few different methods to transfer the pollen from the male to female flower. Some folks rip off the male flower entirely, peel back its petals, and rub the anther directly on the female stigma. I personally don’t love this method… I prefer to leave the blossom in place for the bees, or for later use! Others use a Q-tip. In my experience, a lot of the pollen sticks to the Q-tip itself, leading to less pollen transferring from flower to flower.

This leads us to my favorite method: using a dainty paint brush! I simply collect some pollen from the male, spread some onto the female stigma (or many ladies), and it’s done! Using a paintbrush is really effective, but also feels fun and fancy! Note that I typically use a smaller paintbrush to hand pollinate than what is shown in the video and photos. I can’t currently find my go-to brush…

An image of a small paint brush, covered in yellow pollen. There is a large squash plant in the background that is out of focus. Also smaller images showing the paintbrush inside the male squash blossom, collecting pollen, and another showing the paint brush wiping on the inside of the female flower.
Collect pollen from the male, and deposit it on the female. Boom! Done.


Once the pollen has been transferred to the lady bloom, she will be happy. The immature squash will now grow big and strong! Remember, bigger isn’t always better – especially in the zucchini world! We prefer to harvest our squash at a nice medium size. When squash are allowed to grow too large, they become more tough, pithy, and seedy.

When to Hand Pollinate Squash


Give them some love as soon as they open! And by love, I mean pollen of course.

I have found that most of our squash blossoms open in the morning, and close up by the evening, so checking daily is important if you want to get to them all. However, sometimes they can open at various times of day, so morning isn’t necessarily a steadfast guarantee. If you miss the initial bloom – don’t fret! You can usually carefully peel open blooms that have already opened and closed to access their insides for a couple days after. This goes for both males and female flowers, which is just one more reason to not pick off the males!

Speaking of males and females… I often hear of people experiencing frustration because they have only male flowers, or only female flowers, and not both at the same time. Early in the season, some squash plants do produce one or the other more heavily. They will even out and catch up as the plant matures! Hang tight.

Two side by side images of the same young squash from the same angle. It is small with a large open flower on the left, and larger with the flower now closed on the right - four days after pollination and noticeably larger.
Four days after being hand pollinated. The squash is growing quickly!

To help ensure there will be a good mix of male and female flowers open around the same time, we always grow several squash plants! Did you know you can use the pollen from one squash plant to pollinate the female on another plant, even if they’re a different variety? Yep. You sure can!

Cross-Pollinating Squash


Are your squash plant is coming up short, with either male or female flowers lacking? The good news is: any summer squash male can be used to pollinate a female bloom of a different variety within the summer squash family! For example, you can use a crookneck or yellow squash male to pollinate a green zucchini female. Furthermore, this rings true for the winter or hard squash family too! Pumpkins, butternut, acorn, spaghetti squash, or similar can be used to hand pollinate one another.

Truth be told, in a pinch – any squash can technically cross-pollinate any other squash, regardless if it is a summer or winter variety. They’re all the same species! However, I have heard you get the best fruit development by using summer types for summer types, and winter for winter.

After cross-pollination, the resulting squash fruit will still develop into the designated variety of the mother plant. However, you will likely have issues if you attempt to seed-save from that fruit to grow more in the future. The next generation will not breed true due to the cross pollination that occurred. The fruit that grows from those saved seeds will result in something is different from either of the parent plants.

However, keep in mind that bees will naturally cross-pollinate the squash plants in your garden too! The only way to prevent that is to grow only one variety of squash in a controlled environment. Most home gardeners I know like to plant more than one variety of squash!

We are perfectly okay with this scenario. Instead of attempting to seed-save squash, we simply buy more new seeds every few years. Yes, you can successfully grow plants from seeds that are past their “best by” date! Just sow a few extra as they age. Plus, getting fresh seed enables us to try new varieties. Therein lies the beauty of gardening – trying new things!

So, are you ready to try your hand at pollinating squash?


Here is a video of the very quick-and-easy process. Don’t mind my sense of humor.



It is really THAT simple.

And now you’re off! Go hunt down some squash flowers and help them have sex. May you be blessed with plenty of healthy zucchini this summer. If you find yourself with some large overgrown squash, you should try our Fiesta-Style Stuffed Squash recipe! Loaded with wild rice, black beans, veggies, flavor, and protein… you can’t go wrong.

I hope you found this helpful! Please feel free to ask questions, and spread the squash sex lovin’ by sharing this post!

DeannaCat's signature - Keep on Growing

15 Comments

  • Kristen Loudenburg

    Hello there! I was so disappointed last summer when my zucchini plants didn’t produce any zucchini. I had dreams of harvesting many zucchini and I got several blooms but then nothing happened. I now know I should have helped the plants along with a little squash sex! I have some zucchini plants growing currently but the flowers aren’t opening. Any suggestions?

    • DeannaCat

      They will, just give them time! Usually several days after the flowers form, they’ll open. But they’ll usually only open for one day, or even just part of one day, so make sure to check regularly! I think you’ll have some great zucchini harvests in your near future 🙂

  • Sara

    I tried hand pollinating for the first time and it seems to be working wonders. I didn’t have a paint brush around unfortunately so I did use Qtip. The pollen definitely stuck to it just like you said so I will be getting a paint brush to use for next time! My squash seem to be growing happily and FAST and it was a really fun thing to do! Squash sex for the win!

    • Allyson

      Hi Deanna,
      I was wondering if you need to hand pollinate other fruits/veggies or if it is just for the squash family? I’m growing cucumbers and watermelon and not sure if I need to hand pollinate them?

      Thank you!

      • DeannaCat

        Good questions! Yes, the same can be helpful for them as well! I should have mentioned that in this post… Sorry, too much squash sex on the brain:) The same applies for male and females too – with the ones with tiny fruits attached being the girls. Happy growing!

  • Ashlie

    This article was super helpful and we have seen immediate results after hand pollinating our zucchini and yellow squash plants. I haven’t had any luck with our pumpkins so far this year even with the hand pollination, does this apply to pumpkins too?

    • DeannaCat

      I’m so glad you’re seeing the results! And yes, it should work for pumpkins just the same. We haven’t grown as many pumpkins but I do recall them holding fewer fruit on the vines than summer squash… Maybe that is it? Keep at it!

  • Christine

    My squash plants always rot at the stem between the stem and the bottom leaves. What is causing it and how do I stop/prevent it?

    • DeannaCat

      Hmmm… Where do you live? Have you heard of squash vine borers? Is there sawdust looking stuff, and/or holes in the stems too – or just rot? Or are they simply wilting there? Old leaves do die off right there sometimes – but it shouldn’t be happening with newer growth. Could be a pest/disease, or maybe a watering issue. They have shallow roots and like to be moist, but not soggy. Sorry, there are just so many factors! I hope this maybe helps narrow it down

    • Carolyn Holz

      My mom and I have the same problem . . . . ours has a sawdust looking stuff in the general area. It appears to be vine borers . . . just above the ground level. I am not sure how to prevent these. We have strawed, placed leaves at bottom on broken clay pots and tried a few other things, but not sure how to minimize even more. HELP Deanna?
      Thanks,
      Carol

  • Sherri

    What summer squash varieties do you grow? I saw the dunja zucchini and was curious what your other favorites are. I have raised beds also and I am always trying to maximize space.
    Thanks!
    Sherri

    • DeannaCat

      We love the Dunja as a “regular” green zucchini since it is powdery mildew resistant. This year we are also growing a cocozelle type (which we always do) that is also PM resistant, and it’s doing great! The specific variety is called “Dario” – from High Mowing Seeds. Our favorite yellow summer squash is called “Butta” 🙂

  • Lacey Daniels

    I think I’ve had a summer squash plant of some variety every summer since I can remember, and have never tried hand-pollinating. I’ve always gotten pretty decent results in fruit yield, but now I’m super curious to see how much more it’ll produce with hand-pollinating. Then again, I ended up with 6 zucchini plants I just couldn’t part with this year, so I’ll probably have more than I’ll know what to do with as-is, lol!

    Appreciate all of the posts you do! Super informative, helpful, well-illustrated, but to the point as well.

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