Harvesting perennial seed is something I do a lot of in my own garden. Or rather I should say that when I had my nursery, I did a lot of it. Now, because I’m not producing thousands of seedling plants I only collect my own seed when I really want to maintain a plant population and it is one that doesn’t live for very long (columbine) or that produces easier from seed than division.
Is Harvesting Perennial Seed Easy
There really isn’t much to this.
I wander the garden looking for fat, plump seed pods that are swelling up. When I spot them, I try to remember where they are in the garden clump (some gardeners tie bits of wool to them but I’m not that organized). I watch these seed pods as they mature – they swell up and then stop growing.
Rudbeckia seeds ready for harvesting
When To Harvest
The next step in our harvesting perennial seed journey is when the seed pods often start turning brownish – that’s the key sign I’m looking for in the majority of cases,
I harvest the seed now. Breaking open the case, the seeds are usually contained inside and I dump these into my magic container – an envelope. Write the name of the plant/seed on the envelope and put it into some place you won’t forget. I have all mine filed in a shoebox.
Collecting Open Flower Seed
Collecting daisy seed or other open flower seed is equally easy. Wait until the flower fades and continually watch this seed head. This is a race between you and the birds. They will wait until the seed is ripe to eat it. Their timing is almost perfect. As soon as the seed goes deep brown and separates easily from the flower, it is ripe. Or, as soon as the birds start eating it, it is ripe too. Good luck with that.
Store in the same way.
Some seeds are contained inside of berries. The easiest thing to do with these seeds is to place them in a jar of warm water, mash them up a bit, and let them sit for a few days. This will turn the berry into a soft mess of pulp. Place the pulp into a strainer and run under a tap.
Separate the pulp from the darker, harder seeds. Keep rinsing until the pulp is gone and you’re left with the seeds. Dry on a towel. Store as above when throughly dry.
Don’t Store In Freezer
Some gardeners believe they should put these seeds in the freezer. This is wrong. Store your seeds either at room temperature or in the crisper of the frig. Do not dry-freeze perennial seed. I note that wet-freezing (sowing in a pot of soil and putting outside) is not a problem for the seed as it is genetically adapted to wet-freezing.
Gardeners Regularly Ask Why Not Freeze When Seeds Do Outside Naturally
Note the difference between being put in the freezer and being allowed to freeze outdoors is the speed of freezing.
Indoors, the seed goes from 15C/50F nights to freezing in a matter of hours.
Outdoors, the seed gets colder and colder as the nights get colder. Slowly over a month or more. It acclimatizes to the freezing slowly.
And yes, some seeds may survive the sudden freezing in some years. And a few hardy plants may survive every year. But, it’s far safer to simply keep them cool than take the chance.
Treat your seeds as per instructions in the seed sowing sections – sow immediately outdoors or sow in the frig/baggie system to begin the germination process.
So harvesting your own perennial seed from your garden (to share with friends) or from a friend’s garden is a time-honored way to increase your garden bounty. And an easy one.
Rudbeckia seed heads ready for harvesting.