15 Flowers You Can Still Collect Seeds From in September—Save Them Now for Free Blooms Next Year

By the time August rolls around, I find myself looking at the garden a little differently. Sure, there are still flowers blooming their hearts out, but I’m just as drawn to the ones that are fading. Those dry pods, prickly cones, and crinkled petals? They’re not the end of the story — they’re little packages of next year’s garden, just waiting to be collected.

Saving seeds now means I don’t have to cross my fingers hoping the garden center will have the exact colors I want next spring. I already have them — straight from my own plants. Some I’ll replant myself, some I’ll trade with friends, and a few I’ll give away to anyone who’s just getting into gardening. It’s such a simple thing, but there’s real joy in watching a flower grow from a seed you held in your hand months before.

Some seeds hide in papery pods, others cling to spiky cones, and a few sit tucked away in whimsical balloon-like cases. Each one feels like a little gift from the season we’ve just enjoyed. Here are 15 flower seeds I always make time to save in early fall — so their beauty can return again next year.

Why August Is the Perfect Time to Save Flower Seeds

Early fall feels like the garden’s turning point. Some flowers are still going strong, but many are winding down, their petals fading and seed heads taking center stage. This is the sweet spot for collecting seeds — the pods are dry, the seeds are mature, and you’ve got just enough warm weather left to work comfortably.

I’ve learned not to wait too long. One windy afternoon or a sudden downpour can scatter seeds all over the yard before I ever get to them. Gathering in fall means I get to keep my favorites, grow the exact colors I love next year, and maybe even share extras with friends. Some seeds can even go straight back into the soil now for an early start come spring.

And while I do harvest plenty for myself, I always leave a few seed heads in place. Some flowers you shouldn’t deadhead—like coneflowers, sunflowers, and black-eyed Susans—because it’s better to let them go to seed. Not only will you get volunteer plants next year, but the birds will happily feast on them through the fall and winter. It’s a small way of giving back to the garden that gives me so much.

1: Rose Campion (Lychnis coronaria)

I’ve recently become obsessed with rose campion, so consider this my warning that I’ll mention it every chance I get. I’m smitten by the way its silver foliage and bright magenta blooms create a color pairing that feels both bold and soft at the same time. The more I deadhead it through summer, the more it keeps sending up flowers, but by the time late August rolls around, it definitely begins to slow down.

Even in September, though, you can still collect seed. The pods may look a little weathered by now, but inside they’re packed with tiny black seeds that remain perfectly viable. I like to snip off the whole seed head and drop it into a jar to finish drying.

Sometimes I leave the pods intact until planting time, other times I shake out the seeds right away. One bit of advice—always check the pods before sealing them up. I once discovered a tiny, squirming intruder after a couple of weeks in storage, just as I was about to share seeds with a friend. Definitely not the kind of garden surprise anyone’s hoping for, but a good reminder that even late-season seeds are worth saving with a little care.

2: Poppy (Papaver spp.)

What I love most about poppies is how their beauty lingers even after the petals drop. The pods stand like little ornaments in the garden, each crowned and perfectly round, a reminder that the show isn’t quite over. By late August, and sometimes well into September depending on your zone, they’ve dried to a soft tan and hold a hidden treasure: thousands of tiny black seeds.

That’s the moment I collect them. I snip the pods on a dry morning and let them finish curing indoors, where I can work without worrying about a sudden breeze scattering everything. When they’re ready, I tip the pods gently and the seeds stream out in a fine, peppery trickle. It always feels like gathering something impossibly delicate, and I take my time. A quick inspection before storage is essential too—poppy pods sometimes shelter tiny hitchhikers, and it’s better to find them now than discover them weeks later in an envelope of seeds.

3: Hollyhocks (Alcea rosea)

Hollyhocks will always have a place in my heart, mostly because they remind me of summer trips to the coast—towering above cottage fences, their blooms swaying in the salty breeze. In mid-July they’re at their peak, bold and beautiful, but by late August and into September, the petals have fallen and the tall stalks are lined with drying seed pods.

When those pods turn from green to crisp brown, the seeds are mature. In colder northern zones (Zones 4–6), that usually happens by late August, and it’s best to collect them quickly before cool rains and early frosts ruin viability. In warmer regions (Zones 7–9), the pods often hold on well into September, giving you a little extra time. I simply snap the pods off, crack them open in my palm, and let the smooth, flat seeds spill out. I like to leave a few pods behind so the plants can self-seed and surprise me next year with unexpected colors—nature’s own little raffle.

One last precaution: always check pods before sealing them up for storage. Hollyhock seeds sometimes shelter tiny weevils or other insects, and it’s far better to find them now than weeks later in an envelope. Even this late in the season, a careful harvest ensures you’ll have plenty of strong seed to carry forward.

4: Foxgloves (Digitalis)

I’ve been growing poppies long enough to know that the real magic happens after the petals fall. Those little pods—perfectly round, each topped with a tiny crown—are nature’s version of a pepper shaker. By late August, and even into September, they’ve usually dried to a warm tan and rattle softly when shaken, a sure sign the seeds inside are still mature enough to save.

In cooler climates (Zones 4–6), pods are often ready by late August, and it’s best not to wait too long, since autumn rains can cause mold or scatter the seed. In warmer zones (7–9), the pods can hold their seeds well into September, giving you a slightly wider window. I like to cut them on a still, dry morning and drop them into a wide-mouthed jar to finish drying indoors. At the table, I tip each one carefully so the fine black seeds pour out through the tiny openings at the top. They’re so light they’ll scatter with the smallest breath, so I work slowly.

And just as with other late-season seeds, I always check before sealing them up. Once I opened a pod and found an unexpected little hitchhiker—not the kind of garden surprise you want in your seed stash. A quick inspection saves a lot of trouble later, and ensures those tiny seeds are ready for another season of blooms.

5: Snapdragons (Antirrhinum)

Snapdragons will always remind me of childhood—the dragon-faced blooms that practically beg to be pinched open. They keep gardens colorful right through summer, but by late August and into September, the showy flowers fade and are replaced by tidy rows of seed pods along the stems.

Those pods start out green, then dry to a pale beige or light brown. When they rattle softly or split slightly at the top, the seeds inside are mature. In cooler zones (4–6), this usually happens by late August, while in warmer zones (7–9), you may still find plenty of pods hanging on into September. That’s the time to cut the stems and bring them in. Over a wide bowl, a gentle shake sends out a sprinkling of tiny black seeds that look almost like grains of pepper.

Because the pods are snug little chambers, they can also shelter insects. I’ve learned to crack a few open and check before storage—much better to find an uninvited guest now than weeks later in a seed envelope. With just a little care, even late-season pods can give you plenty of viable seed for another round of those cheerful, nostalgic blooms next year.

6: Sweet William (Dianthus barbatus)

Sweet William has been my little garden experiment—somehow I’ve coaxed it into acting like a perennial, though I know our mild winters deserve most of the credit. By late August, the bright clusters of blooms have faded, leaving behind dry, brittle seed heads that still hold plenty of promise. Even into September, if the weather stays dry, you can gather viable seed before the pods split open on their own.

To collect them, I cup my hand beneath each head and rub gently until the seeds tumble free. They’re small, dark, and easy to store, but I’ve learned not to rush. A quick inspection is essential, because Sweet William seed heads can harbor tiny caterpillar larvae that will chew through a stored stash in no time. Catching them now saves the disappointment later. With a little care, even late-season seeds will be ready to sow in spring or let self-seed for a more natural scatter of color.

7: Zinnia (Zinnia elegans)

Zinnias are pure summer energy—bright, bold, and always alive with butterflies. I pack my beds with as many colors as I can squeeze in, and by late August, the petals begin to curl and dry, a sure sign the season is winding down. Even into September, if the weather stays warm, the flower heads still hold a hidden stash of seeds shaped like tiny arrowheads at the base of each bloom.

I wait until the heads are fully dry and brittle before cutting them from the stems. Sitting with a tray in my lap, I crumble each bloom gently, letting the seeds fall free from the papery petals. They get a little extra air-dry time indoors to be safe, since damp seeds won’t store well. Then I tuck them into envelopes clearly labeled with variety and color—because when spring rolls around, you’ll want to know exactly which bold beauties you’re bringing back.

8: Pansies (Viola)

Pansies have a way of softening even the hottest days of late summer with their gentle, smiling faces. As the season wears on, the blooms fade and leave behind slender, pointed pods that slowly change from green to a pale brown. I harvest them just before they split, cupping them in my palm so none of the tiny seeds escape.

At home, I give each pod a gentle squeeze until it springs open, scattering seeds no bigger than grains of sand. They dry for a few days in a shallow dish, then get tucked away in storage. I always make sure to label the envelopes—pansies have so many lovely faces, it’s worth knowing exactly which ones will greet me first thing next spring.

9: Nigella (Nigella damascena)

I think Love-in-a-Mist might be one of the prettiest seed producers in the garden. By late August, the airy blue flowers have given way to balloon-like pods streaked with pink and green—so lovely that I almost hate to harvest them. But I know what’s inside: tiny, black, teardrop-shaped seeds carrying the promise of next summer’s haze of blooms.

When the pods turn papery and light brown, they’re ready. Even into September, they often stay intact, especially in drier climates, giving you a window to collect. I like to snip them on a calm, dry morning, then crack each one open over a wide bowl and let the seeds spill out like pepper grains. They get a few more days to dry on a dish by a sunny window before I tuck them away for storage. And if I leave a few pods behind, I know Nigella will happily scatter itself into odd corners of the garden—a surprise I never mind.

10: Echinacea (Echinacea purpurea)

Echinacea is the strong, steady type in my garden—standing tall long after the bright petals have faded. By late summer, the blooms are reduced to spiky, dark cones that still manage to look striking, especially when they catch the late-day light. Each of those bristles hides a seed, but they’re only ready when the cone is completely dry and a deep, even brown.

I put on gloves to avoid the prickles, then snip the seed heads and drop them into a paper bag. At home, I give the cones a gentle rub to loosen the seeds, letting them fall into the bottom of the bag. They spend a few days spread out on a tray, just to be sure every bit of moisture is gone, before heading into storage. Come spring, those seeds will bring back another patch of blooms that both I and the pollinators will be happy to see again.

11: Cosmos (Cosmos bipinnatus)

Cosmos are the carefree dancers of the garden—tall, airy, and constantly swaying in the breeze. They keep blooming for weeks, but by late August, the flowers give way to spiky seed heads that look almost like tiny fireworks. I wait until the petals have dropped and the seeds have turned dark brown before harvesting.

On a dry afternoon, I pinch the seed heads right into a paper bag, letting the long, slender seeds fall free. At home, I spread them on a tray for a few days to finish drying. I always label my cosmos seeds because I plant multiple colors, and next year I like to know which variety will be twirling in which part of the garden.

12: Marigold (Tagetes spp.)

Marigolds are the workhorses of my garden—cheerful, easy-going, and generous with their blooms. By August they’re still going strong, but some of the older flowers begin to dry and turn brittle, hiding clusters of pointed seeds inside. Even in September, those papery heads often cling to the plants, giving you another chance to gather seed.

I wait until the flower heads feel crisp and dry before pulling them apart. Inside are neat little bundles of seeds—long and slender, dark at one end and pale at the other. Once freed, I spread them out for a few more days of air-drying, then tuck them into small paper envelopes. Stored somewhere cool and dry, they’ll last until planting time. A single handful can supply next year’s garden with color after color—and keep the cycle of marigolds thriving, brightening beds and helping deter pests season after season.

13: Lupine (Lupinus spp.)

Lupines bring such drama to the early summer garden that it’s easy to forget they leave behind something just as interesting—their fuzzy seed pods. By August, those pods start to turn brown and twist slightly, a sign they’re ready to burst open. If you wait too long, they’ll pop on their own and fling seeds in every direction.

I snip the pods just before they split and drop them into a paper bag. At home, I crack them open carefully, letting the smooth, round seeds fall into my palm. They finish drying on a dish before heading into storage. Lupine seeds can be hard-coated, so next spring I’ll give them a quick nick or soak before planting to help them germinate faster.

14: Scabiosa (Scabiosa atropurpurea)

Scabiosa, or pincushion flower, has this charming, old-fashioned look that makes me feel like it belongs in every cutting garden. By August, the blooms start to fade, and the round seed heads take on a textured, honeycomb-like pattern. They’re almost as decorative as the flowers themselves, which makes it hard to cut them—but the seeds inside are worth it.

I wait until the seed heads are completely dry and a soft brown before snipping them into a paper bag. At home, I crumble them gently over a tray, freeing the seeds from the papery bracts. A few days of air-drying ensures they’re ready for storage, where they’ll wait to bring their fluttery charm back next year.

15: Bachelor’s Buttons (Centaurea cyanus)

Bachelor’s buttons are as easygoing as they come—tough, colorful, and willing to bloom almost anywhere. By late summer, the bright flowers have been replaced with spiky, thistle-like seed heads that feel dry to the touch. That’s my sign to start collecting.

I pinch the seed heads into a paper bag, then rub them gently between my fingers to release the seeds. They’re light and a bit fluffy, so I work indoors to keep them from drifting away. Once they’re dry, I pack them into labeled envelopes. The best part? Bachelor’s buttons reseed so easily that even if I forget to plant them next spring, they’ll probably pop up on their own.