Thursday, October 3, 2013

Seed Saving

This is the major seed collecting time in the gardening calendar. Some seeds have had to be collected earlier, but most are only ripening now, in the fall. Ideally, they should be left on the plant as long as possible to give them time to completely ripen. There is a fine line, however, between making sure seeds are ripe and waiting so long that the seeds are blown off in the wind. Some of the ones I collect are for use the next year (for instance, seeds of heritage tomatoes or of annual flowers, like yellow cosmos). Others I gather to send in for the seed exchanges I take part in.

Bottle gentian seeds

On the whole, the bigger the seed, the easier it is to collect. Some like peonies or canna lilies have huge seeds that are very easy to gather. Apparently, one common name of canna lily, Indian shot, refers to the fact that they were used as ammunition in musket rifles. That tells you how hard they are.

For many, if not for most, of the seeds I gather, I simply take the pod of husk, turn it upside down and shake it. This works very well for the various dianthus. The pods are all facing up and are open at the top when the seeds are ripe. You just break or bend down the stem, shake the pod, and the ripe seeds fall off. Some husks, for instance Nigella damascena (love-in-a-mist), are not open even if the seeds are ripe. However, you simply break the husk, and the seeds fall out.

Collecting Dianthus seeds

Some seed heads, like those of lilies and iris, you simply opened and you find the seeds all carefully lined up in the pod, ready to be gathered. You have to wait till the pod is dry to make sure the seeds are ripe. In the photo below, the lily seed pod is not yet ripe.

Lily seed pod

If you are afraid the wind will blow your seeds away before you have time to gather them, you can simply bag the seed heads and later on retrieve the seeds from the bag. An advantage of this technique is that once they have fallen in the bag, they are most likely ripe.

For most of the daisy-like plants, such as the purple coneflower (Echinacea purpurea) or the various rudbeckias, the seeds are all clustered in the centre of the bloom, and you simply pull them out. You have to make sure you do not end up with only fluff, but also with ripe seeds. That is where winnowing is useful. You put your material in a pan and shake it in a light wind. The chaff is blown away in the wind, and you are left with the seeds which are heavier.


You can also use strainers/sieves of different sizes to sort the seeds from the plant debris. However, I have not much luck with that technique, and besides, I found it difficult to find sieves with different sizes of meshing.

Some plants, for instance lettuce, I let go to seed and collect as much as I need, but most of the seeds are left to scatter. In the spring, the seeds that the wind scattered are always the first to produce strong lettuce plants. I just move these small volunteers where I want them.

The fuzzy white seeds of lettuce

Some seeds come in a fruit or berry. This is the case for instance of pokeweed (Phytolacca americana). You can clean them like tomato seed, that is to say you let them ferment for a while, and the pulps comes off the seeds. For pokeweed, since the seeds are bigger and harder than tomato seeds, you can simply squash the berry between sheets of newsprint, let the pulp dry and then collect the seeds.

Pokeweed seeds

With some plants you simply cannot get the seeds. I have lots of thyme varieties, some that even self-seed, which means they do produce viable seeds, but I have never been able to gather them (thyme would probably be one plant where the paper bag over the seed head technique might come in handy).

It is interesting to note that, even if you collect seeds every year, from year to year your seed crop will vary. Some years you will miss some, other years some plants won't produce seed. So you end up with a different set of seeds most years. For me 2013 was a good year. I was able to gather a greater variety of seeds than usual.


  1. A good tutorial. I've never started many seeds, except tomatoes, so haven't bothered seed saving. Maybe next year.

  2. I've just gone to check the dianthus, but there's no seed at all, even in the pod that still have old petals plugging them up. Hmm. On the brighter side, though, some of the snapdragons are ready! :-D

  3. Fun that snapdragons are mentioned. My granddaughter is in love with snapdragons, and we have quite the stand of them. Then she wanted to collect the seeds for next year (I'm a firm believer in the little pots from the nursery!), so I showed her the few pods already on the flowers. They went right to wherever she keeps precious things.
    The cat also knows where she keeps precious things. He has his own secret place to move them to. I know he's been at work when I find a stray pod on thee floor.

  4. Hello! Have you ever tried gathering seeds from fireweed? And sowing them?
    I brought some back from Alaska to France and would like to give it a try but don't know how. Anyone with advice is welcome!! You can post on my blog

    1. Hi Martine,
      According to Dino (the Bible in seed germination) the temperature should be at least 20C and the growing medium moist. The seeds do not stay viable for much more than a year.

  5. Such an interesting and useful piece. Thanks. I have always been intimidated about collecting seed, but maybe I'll try it now. I was amused to see you collect pokeweed seeds. Here pokeweed is a roadside weed - pretty, yes, but definitely a weed.

    1. It is funny what is a weed in one place and not in an other. Here I have never seen it grow in nature, just in gardens. I like it very much.

  6. I collected seeds from zinnias and annual rudbeckias today. A few of the zinnia seeds weren't ripe but I think I have plenty to fill next years pots. Pokeweed is a weed here, too. Collecting seeds is satisfying and guarantees you get what you want. Some of my zinnias that were supposed to be soft pink were bright cherry red! But I enjoyed the surprise and they ended up being my favorite flowers. :o)

    1. Some plants, especially annuals, seem to hybridize on their own and you might end up with a color or a size different from that of the parents.

  7. I grew some mini cyclamens from seeds from some indoor plants last year and they are just starting to flower so I am interested to see what colour I end up with.

    I also collect seed from my primroses but find they do best of sown immediately after gathering.

    1. Good for you! I find cyclamens difficult to germinate. They are supposed to need total darkness. I have often tried to germinate some of the hardy ones but with not much success. I have a small patch of them but they all came in as corm.

    2. Mine didn't have darkness. As for the hardy varieties - they have self sown all over the garden so much so that many have been dug up and given away.

    3. You are very lucky. Here hardy cyclamens are rather difficult to keep alive. They must be the plants I pamper most. I have seen them growing like weeds in Victoria, British Columbia which has a climate like the southern UK.
      They cannot have complete darkness when they germinate outside. Yet, specialists always insist that you have to keep the seeds covered. You cannot even peep at them as it would let in light! Go figure!


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