Edmonton Native Plant Society
native plant stewards
Harvesting Seeds
by Cherry Dodd on September 3rd, 2010

September is the main seed harvesting month and you will find that with a bit of practice it is easy to save the seeds from your favorite plants.
Not all seeds ripen at the same time, so look at the stems and seed heads to determine if it's harvest time. The seed head should look dry and beige or brown, and sometimes the stem will look dryer or brown too. Of course there are exceptions to this rule. Giant Hyssop seed heads often look purple, and tinged with patches of brown or green - very confusing. But if you just shake the seed head over your hand and you can see the tiny seeds, they are ready to collect.

You can use this method to test most plants with capsule seed heads.  These species include Slender Blue Beardtongue and other penstemons,  Wild Bergamot, or Monarda,  and Harebells. In some species with a capsule type of seed head, such as Blue-eyed Grass, Nodding Onion, and Wild Blue Flax, the capsule will open when it is mature and you will be able to see the seeds inside, but they do not fall out easily. In the case of the violets, the capsules disperse the seeds shortly after they open, so it is best to pick the closed capsules and let them open in a bag. Immature violet capsules are nodding and point towards the ground. Mature capsules point straight up in preparation for opening, so these are the ones you should pick.
Fluffy seeds are the easiest to collect. Daisy-like flowers such as the Asters, Arnicas and Fleabanes all have fluffy seeds. The Goldenrods, Meadow Blazingstar, Groundsell, Golden-aster, Pussytoes and Flodman's Thistle also have fluffy seeds. The seeds are ripe if they detach easily from the plant, so just gently pull them off and put them into a paper bag.
Grasses and sedges can usually be tested by pulling gentlyalong the seed head. The seeds will detach easily when they are mature. Then just cut the stalks and place them in a paper bag.
A lot of species have unique seed heads. Low Milkweed, for example, has big fat pods which split open to reveal tightly packed white silken parachutes, each attached to a flat brown seed. Heart-leaved Alexanders are members of the carrot family and the seed heads look a bit like dill. The flower stem ends in a cluster of smaller stems pointing straight up. These smaller stems each support a cluster of seeds, also pointing straight up. The seeds are ripe when they are brown and detach easily.

Gaillardias' seed heads form balls which are not particularly brown or dry. When the seeds are ripe they will begin to detach and can be seen lying on top of the ball. The whole seed head can then be cut off, but be careful - Gaillardia seeds can be a bit prickly. Later in the season, when the seed head has lost the remains of the flowers and only the seeds are left, the seed head will finally be dry, and will look like a smaller silvery ball. Gumweed lives up to it's name. The seeds are hidden inside an aromatic brown cup that is gummy and very sticky. The Buttercups have relatively large seeds that are often bright green or yellow when they are ripe, but are also sometimes brown. Run your fingers over the seed head. If the seeds fall off they are ready.

Collect seeds by putting them into paper bags so that they can finish drying naturally.  Sometimes it's easiest to cut off the whole seed head. Sometimes you can just shake the seed head over the paper bag. Use a different bag for each species, and be sure to label them or you will end up with "mystery seeds." It's important to use paper so the seeds can dry properly before storage.

Once you have collected your seeds, let them dry for a few weeks before cleaning them and storing them.

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