Zucchini is one of the great summer vegetables. They typically grow very vigorously and are sometimes quite prolific.
Sometimes, you find a zucchini variety that performs way better than the rest in your garden, or gives you super flavorful zucchinis, and you want to save those seeds for next year. Or maybe you just want to save money on buying seeds every year.
Zucchini seeds are some of the easiest seeds to save and store, but require waiting until the zucchini is fully ripe, or what we’d consider overripe. Collecting the seeds is as simple as scooping out, washing, and drying the seeds from your tough overripe zucchinis and storing them in an airtight container in a cool, dry, and dark place.
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When Does Zucchini Produce Seeds?
Zucchinis produce seeds after they are fully ripe, which is way beyond when gardeners usually pick their zucchinis. You want to wait until the zucchini is fully grown and the skin starts to turn brown and the skin is tough and dry. These mature zucchinis are still edible, but they are not tender like your typical, young, green zucchinis.
What I like to do is allow one of my zucchini plants to leave one or two zucchinis to fully ripen after I’ve already picked a few green ones. That way I can still enjoy some fresh zucchinis and then let the plant put more energy into developing the one or two zucchinis and the seeds inside.
One thing to note is that you will get the best results from saving seeds from open-pollinated or heirloom varieties, which are sometimes listed as “OP”. Seeds saved from hybrid varieties (listed as “hybrid” or “F1”) won’t always grow true to type; half your seeds might not grow the same type of zucchini.
Zucchini Flowers and Pollination
Zucchinis, like other members of the cucurbit family (which includes melons, cucumbers, and other squash), has separate female and male flowers on the plant. The zucchini (fruit) develops from the female flower after receiving pollen from the male flower. In fact, behind each female flower is a tiny, undeveloped zucchini. Male flowers are just attached to a thin stem.
If you have several zucchini plants, bees will pollinate your flowers for you. But if you only have one or two plants, or you don’t have many pollinators around, you can pollinate your zucchini flowers manually by transferring pollen from male flowers to female flowers.
How to Save Zucchini Seeds
If you’ve ever cleaned out a pumpkin, saving zucchini seeds is a very similar process. Make sure your zucchini is completely ripe.
Slice your zucchini in half lengthwise and use a spoon to scoop out the inner flesh with all the seeds.
Separate the flesh from the seeds. You can rinse them under cool or lukewarm water to wash them.
After they’ve been washed, make sure they are completely dry before storing them.
Drying Zucchini Seeds After Harvesting
After washing off your zucchini seeds, wipe them dry and then leave them on a paper towel, paper plate, or piece of cardboard to air dry over at least 1 to 2 weeks. Keep them out of direct sunlight. You can also use a fan to help your zucchini seeds dry out faster.
Whatever you do, never use an oven or food dehydrator to dry your zucchini seeds. Roasted zucchini seeds are a nice treat, but to save them for planting, the heat even in a low oven is enough to kill zucchini seeds.
You will know when your zucchini seeds are dry when they can break in half cleanly. Bendy seeds are still too moist, and will likely start molding in storage.
How to Store Zucchini Seeds
After your zucchini seeds are fully dried, you can store them in an airtight container or resealable plastic baggie.
If you have lots of zucchini seeds, you can use old, glass food jars, prescription bottles, or even mason jars for bulk storage.
Keep your zucchini seeds in a cool, dark, dry place. The most important thing is to keep them dry, which is why I recommend an airtight container.
How Long Do Zucchini Seeds Last?
Zucchinis are a type of summer squash, and like all squash, they have a shelf life of around 4 years.
Still, if dried and stored properly, zucchini seeds will last significantly longer than this. However, gradually, your seeds will lose viability. 10-year-old zucchini seeds, for example, will germinate more slowly and many may not germinate at all, so the older your seeds, the more of them you should plant to guarantee getting some sprouts.
Related Questions About Saving and Storing Zucchini Seeds
Can You Save Seeds from Parthenocarpic Zucchini?
Parthenocarpic zucchini plants can produce fruit without pollination. If they are not pollinated, the resulting zucchinis will be “seedless”, only having undeveloped, immature seeds that will not germinate.
However, if you pollinate a female parthenocarpic zucchini flower, it will develop mature seeds when fully ripe.
The problem is that parthenocarpic zucchini are almost always hybrids, meaning that if you save the seeds and replant them, there is no guarantee that next year’s zucchinis will also be parthenocarpic. While it can be fun to save your seeds and see what you get, if you want to keep growing parthenocarpic zucchini every year, you will need to buy hybrid seeds.
Can You Store Zucchini Seeds in the Fridge/Freezer?
Storing zucchini seeds in a cold environment can potentially help maintain their viability for a longer period of time. The renowned Svalbard Global Seed Vault preserves their seeds in a climate-controlled environment kept at -0.4°F (-18°C).
However, a household fridge or freezer is not fully temperature controlled. The temperatures fluctuate as you open and close them, and they are more humid than in a seed bank. If your zucchini seeds are not in a dry, airtight container, they may absorb moisture from the air in your fridge or freezer. The Svalbard seed vault keeps their seeds in 4-ply foil packages in sealed boxes so they always stay dry and protected.
If you plan to save some zucchini seeds for long-term storage, ensure they are in a dry, airtight container before keeping them in the fridge or freezer.
Can I Still Eat Overripe Zucchini?
Zucchini is still edible after fully ripened, although the texture will be tougher and it won’t taste as good. However, after scooping out the seeds, you can add it into soups, stuff it and bake it, or shred it and use it in zucchini bread or cake recipes.
If you don’t want to cook your overripe zucchini right away, you can freeze it for later use.