Originally published in the 2020 September Issue of the WildFlower News
(Photos by author unless otherwise noted.)
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 favourite native plants. I collect the seeds in paper bags as the paper allows seeds to dry so they don’t go mouldy. Always tape the seams on the bottom of the bags as some seeds are so small they can slipthrough the tiniest holes.
Not all seeds ripen at the same time on each plant, so look at the stems and seed-heads to determine if it’s time to harvest. The seed-head should look dry and beige or brown, and sometimes the top of the stem will look dryer or brown too. Of course there are exceptions to this rule. Giant Hyssop seed-heads often look purple - very confusing. But if you bend the seed-head over your hand and some of the tiny seeds fall out, they are ready to collect. You can use this method to test most plants with capsule seed-heads. Often you can see tiny holes in the capsules if you look closely. These species include Slender Blue Beardtongue and other penstemons, Wild Bergamot or Monarda, Harebells, and Alum Root. In some species with a capsule type of seed-head, such as Blue-eyed Grass, Nodding Onion, and Wild Blue Flax, the capsule will point up and open up when it is mature and you will be able to see the seeds inside. They do not fall out easily, but are ready to collect.
Slender Blue Beardtongue seed-heads. The brown one is ready to harvest,the green seed-head is not ripe yet.
Photo by T. Stieben
Nodding Onion seed-head showing the seed capsules open and the seeds inside. Note how brown and dry the seed-head is.
Photo by T. Stieben
Some species break the rule and the seed-heads are still green when ready. Violets are a good example. Violet seeds are quickly expelled once the pod opens, so I pick the green pods just before they open. There is an easy way to tell if a pod is ready. Take a look at the plant and you will see that most of the pods are hanging down. These are the immature pods that are not quite ripe. But one or two pods will be pointing straight up. The pods pointing to the sky are the ones you want. Even though these pods are still green, the seeds are ripe and the pod is about to split open. Put the pods in the bag and close the top. Later you will hear miniature explosions as the pods pop open in the bag. [See Hubert Taube’s article above.]
Buttercups, such as Prairie Buttercup, often flower again in the fall and set seed. They are another species with seeds that are usually bright green or yellow when ripe. Run your fingers over the little green ball that is the seed head. If the seeds fall off they are ready. Sometimes you can see that a patch of seeds are missing - a sure sign that the rest are about to follow.
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, Groundsel, Golden- aster, Pussytoes, Three-flowered Avens and Joe Pye Weed also have fluffy seeds. The seeds are ripe if the fluff detaches easily from the plant, so just gently pull the fluff off. A lot of species have unique seed-heads. Low Milkweed, for example, has big fat, alien pods which split open to reveal tightly packed white silken parachutes, each attached to a large brown seed. As the pods open wider the parachutes open and the seeds float away on the breeze. The fluff is iridescent in the sunlight and it is a wonderful sight.
Photos by T. Stieben Purple-stemmed Aster. When the fluff is a round ball, the seeds are ripe.
Photo by G. Fennell
Iridescent milkweed seeds floating away.
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. Gaillardia seed-heads look like small silver balls when ready. However the seeds often start to detach before this stage and can be seen lying on top of the ball when it is still greenish and not particularly dry - very confusing. Seeds can be collected at both stages, but be careful - Gaillardia seeds tend to be a bit prickly. Gumweed lives up to its name. The seeds are hidden inside an aromatic brown cup that is gummy and very sticky. The seeds are mature when the stem is starting to brown and dry and the sepals are also brown. The sepals are the green collar of tiny leaves that circle the flower just below the petals. Cut off the whole seed-head as the seeds will remain buried in the interior.
Common Tall Sunflower seed-heads don’t look anything like cultivated sunflowers. They look a little bit like Gumweed but without the stickiness. There are 3 layers of sepals and when these sepals turn brown it’s time to clip off the whole seed-head. Rhombic-leaved Sunflowers are a little different. There are no sepals, so harvest them when the whole head is brown and dry. Bend the seed-head over your hand to check for falling seeds. The seeds are miniature versions of regular sunflower seeds and also edible. Some of the pea family members, such as Golden Bean (Buffalo Bean) and Purple Pea Vine have long narrow pods that are ready when dark brown or black.
Left: Goldfinch on Rhombic-leaved sunflowers. They are ready for eating but not collecting - the seed-head is still green. Photo by T. Stieben
Right: Alpine Hedysarum - the only species where the seeds hang in chains.
Grasses and sedges can usually be tested by closing your hand around the seed-head and pulling gently. The seeds detach easily when they are mature and you will find that you have a handful of seeds. Just cut the stalks and place them in a paper bag, or use my method. I use a large paper bag and hold several stems over it at once. I stuff the stems right into the bag and then use my other hand to work through the seed heads and loosen the seeds which then drop straight into the bag.
Once you have collected your seeds, let them dry for a few weeks in the paper bags before cleaning them and storing them. Use a different bag for each species, and be sure to label them or you will end up with “mystery seeds”.Happy collecting!
WN note: It is illegal to collect seed in the wild which includes the river valley, natural areas, public and crown lands.
.ENPS has frequent seed sales at reasonable prices for people who want to expand their collection of native plants.