Saving Summer: How to Harvest and Store Flower Seeds for Next Year’s Garden

The Magic of Seed Saving

As summer starts to fade it's time to start wrapping up the growing season. For me, sometimes it feels like just the right time to finish being out in the garden. I usually start out there around early April and then end around late October, so there's a part of me that's happy to hang up my shovel and prepare for the holidays. I miss the beautiful blooms terribly come January but I'm always planning my spring garden. I think that's really a wonderful part of being a gardener. Right when you need a respite you can start dreaming about next season and take the winter months to reflect back on what worked, what didn't, and what you want to do differently this spring.

Seed saving I feel is a wonderful ritual of fall. You spend all this time growing and nurturing your flowers and they provide their tiny seed babies for you to grow and nurture in the spring. For most people though flowers are cut or enjoyed and then never thought of again. You buy more seed packets and grow fresh flowers again in the spring at an annual cost. But what if you could save some of those seeds you worked so hard to nurture and never have to buy new seed packets again?

As home gardeners we aren't readily taught how to save and store seeds for next season. It's more convenient, and better for seed producers, if we buy brand new seeds every year. But you have all the tools you need right now to save more seeds than you'll know what to do with.

Timing Is Everything: When to Harvest Seed Heads

My first year of trying to save seeds went horribly wrong. The birds and whatever animals were around ate over half of my zinnia heads while we were gone on vacation and I panicked and picked the rest while they were still flowering. Needless to say, that spring I only had three seeds germinate. But now I have a method and a deeper understand of how this all works.

Let's start with Zinnias. They're one of my very favorite flowers and they're very easy to grow and create a variety of beautiful blooms. I love that they flower late into the summer when everyone else has had their time to shine and now the zins get to shepherd in the late summer to fall transition. Zinnias are relatively simple to seed harvest. Let the flowers do their thing and the bees do theres and once the flower wilts away to an unseemly brown color throughout (all the petals should turn from a pretty color to completely brown) then you're ready to harvest. It's even better if you can wait until the stem has also turned brown but who has the time for that?

My first year doing this, as I mentioned, the birds and animals got to the seed heads before I could. And if this starts happening to you I recommend using a mesh netting with some stakes over your flowers. As long as the flowers have been pollinated then they'll start creating seeds. And if it's late enough into the season that birds and animals are trying to eat the immature seeds, then it's safe to say all your flowers are most likely pollinated and worth protecting.

For dahlias it's impossible not to notice when they've gone to seed. If you resist the urge to cut every dahlia you have and place it in a vase to enjoy inside, believe me it's hard, then once they're pollinated they create this little green tent shape from where the flower used to be. And in a few weeks this old flower head will turn brown and it's time to grab the seed head and take it indoors to dry.

Cosmos create this glorious sun burst array of seeds that are very easily spotted. I've even hand harvest each seed without taking the entire pant indoors and I've had great luck with reseeding from previous flowers. Sunflowers create an iconic dark black seed that jam packs its seen head. I like to leave a few sunflower heads out for the birds because they love them so much.

Drying the Harvest: Prepping for Success

Once you've harvest the ripe seed heads you're reading for the next step, drying. A note for zinnias though, you'll know if you've harvested zinnias too early if the seeds connected to the bottom of the petals are still a little green. You might get a few that will seed in the spring but unfortunately it's unlikely. It's really important to be patient, even when it's really hard, and wait for the seeds to fully mature.

On that note, before we get to the drying process, if you have a hard frost coming harvest all of your seed heads and remaining flowers. They will not survive the frost unless you're very skilled and very lucky. For me, I go out and cut everything and enjoy my last few blooms and hope the immature seeds can figure themselves out in the spring. It's better than nothing, but frost is a cruel and will leave no flower unharmed.

But in a perfect word where you've collected some fully mature seed heads before the frost comes, you'll want to lay them out in a well ventilated and dry room. I have a sideboard off my kitchen that works well. I lay out a few sheets of paper towel and drop each category of flower on a paper towel and write down the name below. As much as you'll think you'll remember which is which, and they are distinct, it's better to have them written out just in case. After 1-2 weeks of drying you're ready to move onto the next step.

Separating the Seeds: Removing Chaff and Sorting

Once your seeds are fully dried you're ready to remove the chaff. The chaff is the dried flower debris around the seeds.

• Step-by-step:

  • Gently crumble seed heads over a bowl or tray.

  • Blow or gently shake to separate lighter chaff from heavier seeds.

  • Use tweezers or fingers for precision with small seeds.

It'll feel weird and I do recommend trying to blow the chaff off of the seeds outside if you can without freezing to death by this point. But you'll really want to just blow the chaff out of the bowl only to leave the heavier seeds inside the bowl, that's the goal of this. So it's messy. If you can't go outside lay down an old tablecloth or sheet in a warm well ventilated room and shake the sheet off outside when you're done.

The general motion of this is swirling the bowl around while you blow into the bowl gently, like your blowing out birthday candles. The chaff should just fly out, because at this point it's completely dried out and very light.

Safe Keeping: Storing Seeds for Spring

So now you've gone through the process of growing the flowers, waiting for the seed heads to form, harvesting the seeds heads, drying them, and removing the chaff. This is the final and most important step, how to store the seeds.

The best method I have found to store seeds is in a paper envelope. The seeds need air flow and will mold and rot if you put them in a plastic baggy. (Believe me, I know this from experience). So either grab a few inexpensive envelopes or get fancy with some purchased seed packets that are made of a paper base.

And while you think you'll remember what is in each packet from sight, and it's easy to think this because most seeds look pretty unique like the difference between dahlia and zinnia seeds, please remember to label your seeds. It'll be months before you see these little guys again, so give yourself the best chance of growing the garden you want by labeling what you've worked so hard to save.

When storing your seeds, you'll want a cool dry place. A hall closet or a fridge works very well. I have a wine fridge that I use and it's worked very well. You just don't want the seeds getting very hot, very cold, or very damp. These are all death sentences to your baby seeds.

Once you've got the right location for your harvested seeds they can last about 1-3 years. So if you're planning on saving any of your seeds beyond the next growing season, also add the year they were harvested on the packet as well so you know how long they'll be good for.

A Garden That Keeps Giving

Seed saving is such an underrated part of gardening. It's the unsung hero of the garden truthfully. I hope to get to the point where I can start a seed sharing community in my neighborhood where we all save our favorite flower seeds and share them with each other. What a beautiful way to create community and connection in a time when we need it most. And if you're ever lost for figuring out a thoughtful gift, what's better than a packet of hand saved seeds, a clay pot and some composted soil to give someone to grow their own beautiful blooms?

Not only will you be able to keep on growing the flowers you love by saving seeds, your neighbors, family, and friends will too. I think it's a testament to self-sufficiency to be able to harvest and store your own seeds. And once you get really good at it you can start selecting seed heads based on the flowers you only want to propagate. Or start breeding your or varieties! The possibilities are endless and I hope this gives you the knowledge and support you need to start saving your own seeds.