The Yellow Farmhouse Garden

February 8, 2010

Starting Canna Seeds

Filed under: Flowers,Seed Starting — bob @ 1:32 pm

More is involved in starting seeds than popping them into  potting mix and letting them go.  Some species of plants need to have  special requirements met before their seeds can germinate.

Take for example Canna seeds. Yes, I know that Cannas are normally planted as  bulbs (tubers) in the early summer. However some varieties of Canna are available in seed form. Thomson and Morgan offer their own hybrid variety as seeds.

Anyway, Canna seeds have an extremely hard seed coat that  makes it very difficult for the seed to absorb the moisture needed for sprouting in a timely manner.  Canna seeds are also known as “Indian Shot” because they resemble the BB’s used in shotgun shells.  As a matter of fact, because they are so hard and dense,  at one time they actually were used in shotguns when lead was in short supply.

In order to deal with these difficult seeds,  horticulturists have learned that if you “nick” or sand down a small part of the seed coat, water will penetrate the seed and stimulate germination. This “nicking” process is known as “scarification”.

I scarify seeds by rubbing them on sandpaper until a small spot on the seed coat is worn away and you can see the lighter color of the seed underneath.  Don’t get carried away though, if you sand too deep, you may damage the living embryo inside.

I haven’t found a  really good way to hold the seeds other than with my fingers.  Don’t be surprised if some of your fingernail is worn down in the process.

Using sandpaper to scarify seeds.

Once your seeds have all been nicked soak them  in warm water for about 24 hours.  Keep the water warm for the entire soaking period.

These seeds then need to be planted into a potting mix immediately.  Once they have been treated by this process, they will not keep.

I suggest you start your Cannas soon. They will need a pretty good head start if you want them to bloom this coming season.

By the way, after this summer is over you can dig the tubers from these plants and save them for planting next year just like any other Canna.



  1. If you winter sow, Mother Nature handles scarification and stratification for you!

    Comment by Monica the Garden Faerie — February 9, 2010 @ 12:32 am

  2. Hi Monica,
    Yes, you are right for plants that grow in the temperate zone and further north, oaks, walnuts and other trees are good examples. We can take this point even further by looking at Jack Pine seeds, they need to be exposed to fire before they can germinate. In the case of Cannas, we’re talking about tropical seeds which of course would die if exposed to winter temperatures like we have here.
    Thanks for pointing that out. It’s a great pleasure knowing there are such sharp readers of this blog!

    Comment by Bob — February 9, 2010 @ 10:00 am

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