SSNO part 3: Hand-Pollinating Zucchini for Pure Seed and Better Yields

Posted by Anne Fletcher on

(This is part 3 of our 4-part in-depth seed saving series)

If you remember from Seed Saving Nerd Out (SSNO) Part 2, two categories of plants require isolation for your saved seed to breed true:  Insect- and wind-pollinated open-pollinated crops.  (It's a mouthful, I know.  This chart helps organize the concepts.)

If you want to save pure seed from a wind- or insect-pollinated variety, you have two choices:  Separate plants that could cross-breed by their specified isolation distances (almost impossible in urban and suburban areas) or pollinate it yourself, and then keep other pollen out.

This post will show you how to pollinate zucchini for seed saving.

netted pollinated zucchini flower

(Hand pollinating also increases yields for all types of squash.  If you have lots of flowers, but few squashes, this technique will help!)

Step 1: In the evening, identify one male and one female flower poised to open, and tape them shut.

If you don't yet know how to identify flowers about to open, spend a few days checking on your zucchini in the evening and then again in the morning to see how the flowers look in their various stages.

Identify female flowers by the mini-zucchinis at the base.  Male flowers are on a plain stem.

male zucchini flower

This is a male flower, taped shut, at night.  You can see the plain stem below the blossom.

female zucchini flower

This female flower has a mini-zucchini at the base.  You don't have to go out and tape them shut in the dark (evening is fine), but it was pretty exciting rummaging around in the plants with all the night insects buzzing around my headlamp!

Step 2: The next morning, find your flowers and remove the tape.

male zucchini flower

When you see the flowers in the morning, it's easy to tell why you taped them shut. They're bursting to open!  They open early in the morning and pollinators will get in there before you.  (I hand-pollinated and took these pictures at about 7am, and the pollinators were already busy on the open flowers.)

female zucchini flower

Step 3: Pick the male flower and remove its petals

male zucchini flower without petals

This makes a little pollen paintbrush for you!

Step 4: Rub the pollen all over the inside of the female flower.

female zucchini flower

female zucchini flower lady parts

Get that pollen all over the structures at the base of the female flower.

Step 5: Net the female, and mark it. (Skip this step if you're just interested in bigger crops, but not seed saving.)

netted pollinated female zucchini flower

Now that you've pollinated your zucchini flower with pure zucchini pollen, you don't want any bees coming along with other squash pollen to contaminate your seeds.  So either tape the flower shut again, or net the flower.  I'm using one of those reusable net produce bags because the drawstring at the top makes it easy to close.  But really anything that keeps the bugs out will work.

I've also got a pink bow that will stay on the zucchini all the way until harvest so I know which one is for seed saving.  (I'll probably have to loosen and move the bow as it grows!)

Now we just wait and watch it grow until the skin is hard.  

Click here to see the mature zucchini 5 weeks later, and the process for cleaning and saving the seeds.

- Or -  

Click here to see the final part in the seed-saving series: how to adapt varieties to your own microclimate. 

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  • Hi Anne, I have always wanted to harvest zucchini seeds, as I do for my melons, peppers, tomatoes, and winter squash. But zucchini I grow never seem to have mature seeds. Is this because I do not leave the fruit on the vine long enough? I would think the squash would be enormous if left on the vine. I find it’s the same with cucumbers as well. I would be interested in seeing your final picture be for you harvest the seeds. I also used my new Orta pots to sprout lettuce, kale, broccoli rabb, and cabbage. The plants are ready to go in the ground. Looking forward to trying my spring crops in the pots as well.

    cecilia michaels on
  • Thank you so much for this article and link to the isolation distance chart. It is the clearest explanation I have ever seen, especially with the photos. I am growing round green zucchini and regular yellow zucchini, and the green zucchini often grow in an oval shape due to cross pollination from insects. Strangely, the yellow zucchini never seems to be affected. Also of note, it may be that beans are self-pollinating, but I grew bush beans in raised beds for years from saved seeds, and grew 2 types of pole beans at the end of the beds, but in the last few years I began to notice the effect of cross pollination so that some of the bush beans grew like pole beans. This year so many of my bush beans are growing like pole beans that they are covering the cyclone fence behind the beds. Next year I am going to start with brand new seed and keep the different types of beans as far away from each other as I am able to do in my small yard.

    Priscilla Lehman on
  • Thanks for all the helpful tips on pollination Anne. I can’t wait to see what my harvest yields. This has been such an exciting process. I watched as my butternut squash plants sprouted from seed in one of your Orta starters over two months ago. Observing my squash plants grow has become a daily therapy during this crazy Covid-19 year. Next step is pollinating all of the female flowers I’m finding. So far it looks like 4-5 females per plant.
    Who know’s, I may turn out to be a gardener after all!

    Lori Morris on

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