With special preparation, cannas can be grown from seed

Cannas, sometimes called canna lily, are tender tropical plants that are generally planted as bulbs (tubers) in the early summer after the soil warms up. Many gardeners dig up and save their canna bulbs from one year to the next. I’ve blogged in the past about how to save canna tubers.

Many gardeners are not aware that canna can also be grown from seed. Not all varieties are available as seeds, but some seed sellers offer their own canna hybrids.

Many years ago, I grew a colorful dwarf variety of canna from seed. They were bred to produce a wide range of colors yet still be small enough to thrive in pots as small as 6 inches. Those particular canna seeds were only available to commercial plant growers.

Growing cannas from seed has its problems. The 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. 

They are so hard and dense, at one time in previous centuries, they actually were used in shotguns when lead was in short supply. People referred to the seeds as "Indian Shot" because they resemble the BB's used in shotgun shells. 

In order to help sprout these difficult seeds, they need to be “scarified”, not to be confused with “stratified” which is an entirely different seed treatment.

Scarification involves making a small nick on the seeds surface, or more commonly filing down a small part of the seed coat. This enables water to penetrate the seedcoat thereby stimulating germination.

You can scarify seeds by rubbing them with a small file or a piece of sandpaper. Hold the seed firmly with your fingers and rub until a small spot on the seed coat is worn away. Don't get carried away; if you sand too deep, you may damage the living embryo inside. If you can see the lighter color of the seed underneath, you’ve gone far enough. 

I haven't found a really good way to hold the seeds other than with my fingers. If you try this, don't be surprised if some of your fingernail gets worn down in the process.

Once your canna seeds have all been scarified, soak them in warm water for about 24 hours. It’s important to keep the water warm for the entire soaking period, do not let it get cold.

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

Canna from seeds need a pretty good head start if you want them to bloom this coming season. February is the ideal time to start canna seeds in our area.

You can also save canna seeds from your own plants. That involves letting the flowers fade and mature enough for seeds pods to form and the seeds inside the pods to fully ripen.

If you want, you can dig the tubers from your seeds-grown canna plants after summer growing season is over and save them for planting next year just like any other canna.

Other seeds benefit from scarification too. Some of the more common ones include morning glory, mallow and sweet pea.

Working with specialized seeds like these can help provide a hopeful outlook during this last part of winter as we look forward to the first day of spring, only five weeks away.