How to Save Pumpkin Seeds for Next Year: 7 Pro-Tips
If you loved growing pumpkins this year, why not try to save the seeds and grow them again next year? Instead of buying more, you can attempt to re-create this year’s bounty. The straight-forward process will be even more successful with some pro tips. Plant biologist Emily Estep shares all you need to know about saving pumpkin seeds for next year.
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There’s nothing more autumnal than growing your own pumpkins, whether you display them near your front door, carve them as jack-o-lanterns, or process them into pie. Among these fall traditions, you can also save their seeds for the next growing season.
There are a handful of reasons why you may want to save your pumpkin seeds for next year, as tempting as it may be to roast and eat them instead.
Perhaps you grew an A+ pumpkin that you’d really like to grow again next summer. Maybe you want to start cultivating your own personal “variety” that you share with friends and family. Potentially, you’d just like to save money.
Or possibly, you just want to figure out if you can. Fortunately, the process is not too complicated, especially with the help of these tips. We’ve assembled all the tricks you need in addition to the main steps, so you can save pumpkin seeds for next year like a pro.
Avoid Cross-Pollination
Many gardeners who are new to growing pumpkins don’t realize that the seeds they harvest from the fruits of their labor may not germinate and eventually produce more fruit that look the same next year. This is because of cross-pollination.
Pumpkins are one of the many varieties of Cucurbita pepo, among winter squash, summer squash, and other gourds. If you’re growing both pumpkins and butternut squash in the same yard, it’s likely that pollinators used pollen from one to pollinate the other.
The resulting fruit from the pollinated flower will look like the fruit you intended, but the seeds inside will produce hybrid fruit that are a combination of the two parent plants. This is crucial information for gardeners hoping to re-grow the same plants next year.
If you’re cultivating multiple cucurbits, there are a few ways you can attempt to prevent cross-pollination:
- You can hand-pollinate flowers early in the morning, choosing a male and female flower from the same plant or same variety.
- You can secure bags over flowers before they open, controlling which pollen is available to pollinators.
- You can try growing different varieties about half a mile apart or more, if you have the space.
If saving pumpkin seeds for next year wasn’t initially in your plans, you may have planted all sorts of pumpkins and other cucurbits. In which case, it’s probably too late to avoid cross-pollination. Keep this phenomenon in mind for next year.
However, if you’re just growing pumpkins—without any other cucurbits in sight—then you should be able to replicate your plants next year. They should be true to seed.
Gather a Lot of Seeds
If you want the best possible seeds for germination, then you want the healthiest, most robust pumpkins. Likely, your pumpkins are already in great shape, which is why you’re hoping to replicate them next growing season.
Avoid any stunted, sickly, or unusual-looking pumpkins, if possible. Wait until the pumpkins are fully mature. You’ll know they’re mature when they’ve stopped growing size, reached their final color, and when their stems start to harden and brown.
If the vines themselves are starting to wither away, this is a good sign of mature fruit. Immature gourds will have undeveloped seeds that will not germinate, so don’t waste your time. If a pumpkin is still small and pale green, go ahead and toss it into your compost.
With large, healthy, and mature pumpkins on hand, now you’re ready. Gathering as many as you possibly can will make a real difference since you’re saving them for next year.
Some may not store well, some may decay, and some may have never been viable to begin with. By starting with a large amount, you increase the likelihood of germination next year. So, while it may be tempting to give a pumpkin a few scoops and then move on, lean into the process and collect a ton.
There are many tools you can use for scooping, including those that come with a standard jack-o-lantern carving kit. However, if you’re not attempting to maintain the aesthetic shape of your pumpkins for Halloween decorations, you can be quite aggressive when harvesting.
Don’t worry too much about pulp, etc., at this point. Just get as many developed seeds as you can.
Remove the Pulp
The next step is to remove all the pulp. Cleaning up now will make it easier for you to decide which seeds are the best instead of selecting from a pulpy mess.
An easy way to do this is to put the pulpy mess into a colander and rinse it under the sink. A sink with a spray attachment can make the process go faster. You could also try this technique outside with a hose if you don’t have a spray attachment in the kitchen.
If you keep the process clean and hygienic, you can save and use the pulp to make your own pumpkin puree. Remove any stringy bits and bake what remains. Put it in a food processor, and you’ve got homemade puree.
With a little bit of pumpkin spice seasoning, you’ll have multiple ingredients to make pumpkin bread, pie, and other seasonal treats. Perhaps these autumnal flavors aren’t your favorite. Toss the pulp into your compost bin, and nothing is wasted.
Pick Out the Best Seeds
Now that you’ve gathered a bunch of healthy seeds and have removed the pulp, you can take a good look at your bounty and toss any that are subpar. This is why it’s a good idea to have started with so many; now you’re going to narrow down the selection.
Remove any that have an odd shape or off-color. Small ones may not be viable or fully developed, so get rid of those too. (Or roast them for a little snack.) This can save you time down the line. You don’t want to waste any time or space attempting to germinate any that are weak or sickly.
You want to save the biggest, most uniform findings for next year’s growing season. These are the ones that have the best chance at germinating and presenting you with next year’s best pumpkin.
Ferment
Next, try your hand at fermenting. This isn’t 100 percent necessary but can make a significant difference for multiple reasons.
One, though you probably removed nearly all the pulp, the fermentation process removes the rest. This will decrease the likelihood of rotting and fungal growth while in storage or winter long. If you skip to drying now, you may discover mold in spring.
Two, fermentation naturally helps remove trace amounts of bacteria and fungi that can lead to disease down the line. It even assists in eliminating seed-borne pathogens. Bacterial leaf spot is an example of a seed-borne disease that affects pumpkins and other squash.
Finally, fermentation breaks down the gelatinous outer lining. This will both speed up the germination process and also increase its success rate.
If you think about it, this is what happens in nature. Fruit falls on the ground, and then it ferments. This is why fermentation is a common way to process the seeds of fresh tomatoes and other garden crops.
To ferment, drop the seeds in a jar of water, and cover it loosely with a lid. Do not squeeze the lid tightly shut. It should be just barely closed, allowing gasses created during fermentation to escape the jar. Leave the jar alone, at room temperature, for three or four days.
Then, stir the mixture, and remove any seeds that have floated to the top. They are not viable, but those that have sunk are good to go. Drain and rinse the viable seeds.
Dry and Store Properly
It’s really important that you dry thoroughly since you will be storing them for a long time. If they aren’t dry enough, they could rot.
The simplest way to do this is to spread them out on a single layer, on a baking sheet, paper bag, or other clean surface. Make sure none of them are on top of each other. Let them sit in a cool, dry place until fully dry. This could take a few days.
Another method is to place them in the oven at 150°F (66°C) for three to four hours. Be sure to stir them around occasionally so none of the sides burn. You can also use a dehydrator. Set it to 115°F (46°C), leave the seeds for about an hour, and check on them. Leave them for another hour if they’re not yet dry.
Once they’re dry, store them properly. Place them in an airtight container and keep them somewhere cool and dark. Avoid damp basements, hot garages, and outdoor garden sheds that may heat up.
As long as they don’t spoil, they may remain viable for years. This is one of the reasons why you should label them with the plant name and date. It may seem obvious to you now, but in the future, you could forget.
Take Notes
Lastly, take notes all along the way. What made you want to try out this process? If you grew particularly stellar pumpkins, write a bit about them in a garden journal. Add details about their dimensions, the year’s weather, and just what made them so special.
Did you have any issues with pests and diseases that you’d like to prevent? Since you’ve invested so much energy in gathering, processing, and storing, you’ll want to prepare yourself to protect them next year. Note any issues from this year, research prevention techniques, and arm yourself with knowledge.
Also, record details about the seed-saving process. Perhaps you discovered that many of your seeds weren’t viable, and you’ll want to look back through the steps to try and figure out why. Perhaps they all germinate spectacularly, and you’ll want to repeat these exact steps next year.
It’s also fun to experiment. Maybe you fermented half of the seeds, but you skipped fermentation for the other half. Which ones had a higher germination success rate? This is the information that “future you” will want to know.
This may be the beginning of a hobby that spans for years, and you’ll be glad you have the data from previous summers. Taking notes when gardening can really help you improve your techniques over time.
Next year, when you’re harvesting pumpkins yet again, you’ll be glad you have notes to reference.
