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Fall Seed Collecting, Cleaning and Storage

Updated: Apr 2

by Cherry Dodd, WF News, Oct 2022


Seeds can be collected from late spring onwards depending on the species, but fall is the main seed-collecting time. Seed collecting is easy, once you follow the main rules. These are:

  1. Wait for the seed head to become brown and dry before collecting the seeds.

  2. Fluffy seeds are ready for collection when they detach easily.

  3. Always use paper bags or envelopes when collecting.

  4. Leave the seeds loose in the paper bag for 6 weeks before storing them. This allows time for the seeds to cure and finish drying.

Even when it looks like all the seeds have gone, there are always a few seeds left and just a few seeds will give you plenty of plants in the spring. So let’s start with the easiest seeds - the fluffy seeds.



Fluffy seeds

Purple stemmed aster, Symphyotrichum puniceum
Purple-stemmed Aster, Symphyotrichum puniceum

Fluffy seeds are typically round white balls of fluff and they are very easy to collect. Take a pinch of fluff and pull gently. If the fluff pulls away from the seed head it is ready. Pop it into a paper envelope or a paper bag if you are collecting a lot. Label the bag well with the name and year or you will end up with a bunch of mystery seeds. Although most fluffy seed heads are white a lot of species have different coloured seed heads. For instance, Arctic aster’s seed head is a lovely tan colour with a touch of pink. Meadow blazing star’s seed head is again quite different. It is larger and not so fluffy looking. This is because bits of the old dried flower stay on the seed head and interfere with the fluffy look. Fluffy seeds will need to be stored in a paper bag for six weeks before final storage so they can dry properly. You do not need to take the fluff off. Storing the seed in paper is important as the seeds still have to dry some more, and they might go mouldy in a plastic bag. You can fold the top of the bag. It doesn’t have to be open. I usually leave the bag outside with the top open, in a secure bucket for an hour after collection. Tiny spiders are often accidentally collected along with the seeds. The open bag policy allows these hitchhikers to leave.


Pockets and Capsules

Giant hyssop, Agastache foeniculum
Giant hyssop, Agastache foeniculum

Some seed heads, such as giant hyssop, have tiny pockets where the seeds are hidden. The pockets open at the top quite early and you can see the black seeds inside. But how do you tell if the seeds are really ready?


Usually, with most pocket species, it is when the seed head is brown and dry. However, Giant hyssop likes to surprise us. The seed heads often keep a lovely blue or pink colour, or Purple-stemmed aster, Symphyotrichum puniceum even stay green when the seeds are ready. So here is how you can tell if pocket seeds are ready when it is hard to tell from the seed head itself. Hold out your hand, palm up, and with your other hand bend the seed head over your waiting hand. If tiny specks fall onto your hand the seeds are ready. Collect the seeds by cutting the whole seed head and placing it in a paper bag.


Wild bergamot is another flower where the seed heads have tiny pockets and it is difficult to figure out when the seed head is ready to release its seeds. So with this flower, and any with similar seed heads, do the same hand test. Bend the stem and see if seeds fall out. Cut the whole seed head and put it into a paper bag to finish drying. All seed heads should be stored in paper bags or envelopes for six weeks before cleaning and final storage.


To clean this type of seed, put the seed head in a clean jar or tin with a secure lid and shake up and down for a minute or two. The seeds will be shaken loose and will fall to the bottom of the container. Lift the seed heads out and compost them, and then pour the seeds into an envelope.


Gaillardia or Blanketflower – What a showy flower! Gaillardia seed heads are in a category of their own. They look like they are going to be fluffy - the seed head is a small white ball when it is ready for harvest, but these seeds are spiky and feel a bit prickly to the touch. Gaillardia seeds are tricky. Sometimes they will detach and sit on top of the seed head while the remains of the flower are still present and before the seed head reaches the round spiky white ball stage. However they are ready and can be collected at this time. You can tell they are ready because they are already separating from the seed head. You can see this process in the photo on the left. Cut off the whole seed head and store it in a paper bag.


The seeds of Nodding onion are held in little pockets which open wide at the top. When you can see the large black seeds, they are ready to collect, even though they don’t fall out. Just cut the whole seed head and pop it in a paper bag. The best way to clean Nodding onion seeds is to roll them with a rolling pin. It won’t hurt the seeds if you are gentle.


Rhombic-leaved sunflowers and common tall sunflowers. The seed heads are completely different from garden sunflowers. They are a closed pocket with the remains of the flower covering the top. So it’s hard to tell when the seeds are ready. Look for a brown seed head. Often the top of the stem is beginning to brown and dry too. Then pick off the debris covering the top of the seed head, and do the hand test. Bend the stem over your hand and see if the seeds fall out. In this case you might have to give the seed head a little shake. Another way to collect the seeds is to wait until the seed head is bare and open. Most of the seeds will be gone, but there will be enough to collect. Cut the whole seed head, and pop it into a paper bag for six weeks.


Seeds in Capsules

Blanketflower, Gaillardia aristata
Blanketflower, Gaillardia aristata

Penstemons, such as Slender blue beardtongue, and Lilac-flowered beardtongue, have masses of tiny capsules attached to the flower stem. When the seed heads are brown and dry and the capsules have a tiny opening at the top of each one, they are ready for harvest. The seeds are so fine that they look like dust. Make sure your paper bag is taped along any cracks so the seeds don’t escape. I like to use the liquor store wine bottle bags for fine seeds.


Harebells are the same. The tiny capsules are brown and dry and have small holes around the top for the seeds to be released. These seeds are also as fine as dust. When Wild blue flax seed heads are ready for harvest, the capsules are a light beige and dry and open, exposing the seeds. The seed heads do not all mature at the same time. On one flower stem there will be buds, flowers, young green pods, older green pods, closed beige pods and open beige pods. So collecting means being picky and choosing just the right ones. To free the seeds when it comes time to clean them, use a rolling pin to flatten the capsules and release the seeds.


Plants with Pods

Low milkweed, Asclepias ovalifolia
Low milkweed, Asclepias ovalifolia

I love pods. They are so easy to see. All violets such as Early blue violet and Canada violet have pods. However, there is a trick to collecting any violet seeds. They have to be cut and bagged while they are still green, because once they open the seeds are shot out of the seed head very quickly, and in a couple of hours only the empty pod is left. So how do you tell which green pods are about to open? It’s easy. Pods that are pointing straight up are ready to open, even if they are still green. Just collect the upright pods each day, put them in a paper bag, and close the bag. In a couple of hours you will here a strange noise. A snap, crackle, pop as the seeds are shot out. This process leaves you with clean seeds and empty pods, and it is easy to separate the two.


Low milkweed.

The pods are the most spectacular part of this flower. The pods are small at first, but soon grow quite large. When the seeds are ready, the pods open and a mass of iridescent white fluff emerges and sails away. Each tuft of fluff carries a large seed. The seeds are very easy to collect, you can cut the whole pod as soon as it splits open, but before the seeds emerge. However put them into a large paper bag. The seeds are so buoyant that they will float right out of the bag again with the slightest breeze. Clean these seeds outside so you don’t end up with fluff all over your house. These are the only fluffy seeds where Giant hyssop, Agastache foeniculum Blanketflower, Gaillardia aristata Low milkweed, Asclepias ovalifolia I take off the fluff. It makes them a lot easier to handle.


Fireweed

Fireweed is another species that has pods that contain fluffy seeds. When the long, narrow pods are closed the seeds are not ready. Once the pod opens it is easy to pick off the seeds as they sit exposed to the air for a while before drifting away. Put them in a deep bag as they tend to float out of a small bag every time it is opened. Fireweed seeds are hard to grow, and the plant does not usually self-seed, so don’t worry about all the fluff filling the air and heading over to your neighbours. Golden bean is also called Buffalo bean because it flowers in the spring at the same time that the bison used to return from their winter grounds. The pods are large and easy to spot. They look a little bit like regular dried bean pods. They can be collected once they are a beige colour and dry.To clean them, just split the pods open and take out the small, shiny, kidney shaped seeds.


Naked seeds

Heart-leaved alexanders, Zizia aptera
Heart-leaved alexanders, Zizia aptera

These are seeds that don’t have a protective pocket, capsule, or pod. Tall meadowrue and veiny meadowrue are good examples. The seeds sit in little clusters at the end of the stems that once held the flowers, and they break off very easily once they are ready for collection. Heart-leaved alexanders are another good example of un-winged seeds.











So, to recap:

Seeds are ready when they detach easily from the seed head, or fall out of the pocket or capsule holding them, or in the case of Nodding onion, they can be easily seen. Always collect them in paper bags, not plastic. Store in the paper bags in a cool place for six weeks to allow the seeds to cure and finish drying.


Cleaning

Most fluffy seeds do not need cleaning. You don’t have to take off the fluff. Pocket seeds and capsule seeds can be shaken in a tin or jar to shake them loose. Un-winged seeds do not need to be cleaned. However nodding onion and wild blue flax need to be crushed with a rolling pin to release the seeds, or the seeds need to be peeled out of their seed heads.


Long term storage

Once the seeds are dried and cured they can be stored in envelopes, bags, or pill bottles. Your choice. They should be stored away from sunlight in a cool place such as a basement shelf or cold storage room. You can also put them in the freezer in freezer bags. Native seeds keep for a long time, five or even ten years.

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