If you grew some particularly beautiful zinnia flowers this year, your enjoyment of those blooms doesn’t have to end with the season. Yes, zinnias are annual flowers, so your original plants will die after your first fall frost. But you can save seeds from the most beautiful flowers so that you can plant them and enjoy them again next year. Zinnia seeds are incredibly easy to harvest and save for the following spring.
That means you can buy just one package of zinnia seeds and turn them into an endless supply. You’ll never have to buy another zinnia seed or plant again (unless you find another variety you love because, honestly, who can stop at just one?)
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WHAT TYPES OF ZINNIAS CAN YOU SAVE SEEDS FOR THE FOLLOWING YEAR?
You can save seeds for many different varieties, but you do need to pay attention to the type of plant you’re growing—open pollinated or hybrid—if you want future generations to grow true to their parent plant. This information is usually on the back of the seed packet.
Open pollinated means the flowers are pollinated by bees, butterflies, moths, and more. Seeds from open-pollinated zinnias should grow to look just like the flowers from the plant they came from. That is, unless you’re growing lots of different zinnia varieties in close proximity and a pollinator (or strong wind) brings pollen from one variety to another. Heirloom varieties are open pollinated.
Seeds from hybrid zinnias might not grow true to form. Just because the parent plant has double flowers or magenta petals doesn’t mean the next generation will. Your seeds should still produce flowers, but you may find yourself disappointed with the blooms if you had certain expectations.
A good rule of thumb for the vegetable garden in general is to save seeds for open-pollinated plants and buy new seeds for your favorite hybrid varieties when you run out.
WHEN TO HARVEST ZINNIA SEEDS
Throughout most of your growing season, your goal should be to deadhead spent blooms as soon as they’re looking a little past their prime. This keeps your zinnia plants super productive rather.
Wait until the end of the season before you switch gears and focus on seed collection. Then, you should let flowers that are fading and shriveling linger on your favorite zinnia plants instead of removing them. At this point, the plants will be coming to the end of their life cycle, and you’ll notice dark gray spears hanging out in the middle of each old bloom by the dozens. Those are the precious seeds themselves!
Note: Taking flowers from blooms that are still in their prime will give you immature seeds that won’t amount to much next year.
The best time to save zinnia seeds in colder climates is late summer through early October. In warmer climates, we can enjoy blooms all the way till around November before we near our first anticipated frost date.
STEPS TO SAVE ZINNIA FLOWER SEEDS
Wait for a nice, dry day, and then follow these steps to save seeds from your favorite flowers.
Step One: Cut zinnia flowers
Leave the flowers on the plant until they’re dry to the touch and brown around the edges. They won’t be beautiful anymore, but that’s okay. Their mission is complete. They’ve been hard at work creating hundreds of seeds for next year.
Use a clean pair of pruners or scissors to cut the stems a couple inches beneath the flower heads. Keep flowers from different varieties separate. Bring your harvested zinnia flower heads inside.
Don’t save seeds from plants that have suffered from diseases like powdery mildew. Seeds can actually be contaminated with fungus and bacteria from the parent plant.
Step Two: Let flowers dry
If you left a good bit of stem on the flowers, you can tie them in a bunch and hang them up to dry. Otherwise, you can spread flower heads out on a screen or large mesh colander. Place your blooms somewhere dark and dry inside your home while they dry out. This can take anywhere from a couple of weeks to a full month, depending on how much moisture was still in the spent flower head. Any moisture remaining in the zinnia seed heads can cause mold or mildew in storage later.
Step Three: Store the dried flower heads over winter
The easiest way to save the seeds once the flower heads are completely dry is just to toss the flowers whole in a clean jar, a seed saving envelope, a paper bag, or a plastic baggie. I like to keep the seeds attached to the dried petals so that I can tell what color the future zinnia blooms will be when I’m planting next year. Again, you’ll want to use separate envelopes for each zinnia variety and label each one if you want to be able to plant specific varieties next year. (Or mix them and create your own zinnia surprise seed mix!)
You could also take the time now to remove the petals if you prefer. Spread a paper towel or plate over your counter and rub the flower head between your fingers to release the seeds. You might need to gently pull individual seeds from petals. Discard the petals.
Note: If you can press your nail into a zinnia seed and leave an impression behind, they’re not fully dried out yet. Spread the seeds out and leave them to dry for a few more days.
Make sure to label your jar, paper envelope, or baggie with the type of seed collected and the date. You’ll store the seeds in a cool, dry, and dark place all winter long. Zinnia seeds don’t need any stratification or anything, so you’ll want to wait until your last frost date has passed the following spring to plant them outdoors.
WHAT DO ZINNIA SEEDS LOOK LIKE?
Zinnia seeds are small and shaped like little arrowheads. They form at the end of the petals (those petals are what help zinnia seeds scatter in the wind so that they can find new places to grow, which is pretty cool). Viable seeds are typically more gray than tan.
HOW TO SOW YOUR ZINNIA SEEDS NEXT YEAR
Next spring, you can direct sow your zinnia seeds in the garden once your last frost date has passed. (If you prefer to start zinnia seeds indoors to get a head start on your growing season, make sure to check out our seed starting guide for tips and recommended seed starting supplies.)
Make sure to pick a spot that gets at least 8 to 10 hours of direct sunlight so that your zinnias will be able to produce a lot of blooms for you. Other than the light requirement, your zinnias won’t be very picky about where you plant them. You can grow them in the ground, in a container at least 12 inches deep (make sure there’s a drainage hole in the bottom), or in a raised bed.
If you kept the flower heads intact, rub them between your fingers to separate the seeds. Then follow these simple steps to sow your zinnia seeds and start their beautiful life cycle in your garden all over again!
Step One: Prepare the planting area
Add some finished compost to the planting area. This should give your zinnias all the nutrients they need to grow for their entire time in your garden.
Step Two: Spread the seeds
You can take a bunch of seeds in the palm of your hand and sprinkle them over the planting area, or you can space the seeds about 4″ to 6″ inches apart, depending on how large the mature flower heads are expected to be. If you kept some petals attached to remind you of color or if you were careful to keep different varieties separate and labeled, you can plant strategically to show off your favorite bright colors.
Step Three: Cover & water
Cover the seeds up with a light layer of soil or compost. Water the planting area well to tell the seeds it’s time to sprout. You’re only about 60 days away from your first set of beautiful blooms.
HOW LONG WILL YOUR ZINNIA SEEDS KEEP?
The drier the seeds were when you stored them, the longer they should keep. Most zinnia seeds should remain viable for up to 6 years, but it’s a good idea to use up these seeds within 3 years. (You can, after all, collect a fresh batch every year, so why not use them up?)
When we say viable, that just refers to their ability to sprout. The likelihood seeds will ever sprout goes down over time. If you find an old jar of zinnia seeds, you can always toss them out in the garden and see what happens!
It’s Zinnia Seed Harvest Time!
That’s all there is to collecting and saving your own seeds for your favorite zinnias (for free!). If you store seeds from your best flowers every year and then plants those seeds the next, you’ll eventually end up with seeds that are uniquely suited to your exact climate. It’s pretty incredible to think about!
Once you’ve built up your own vast collection of dried seeds, make little packets of zinnia seeds to share with your friends. Tell them these are the easiest flowers to grow and they will fall in love with their zinnias (and all the butterflies they attract) very soon.
Let us know if you have any questions about saving your own zinnia seeds in the comments below.