Canna garden seeds are produced by their flowers being pollinated either by the human hand or by a range of insects or honey eater birds.
Once pollination has been done the production of the seed commences.
Hand pollination is most successful early morning well before most bees and insects come out.
If you venture outside mid morning then its most likely too late as the insect would have beaten you too the cannas new flowers already.
From pollination to a ready to harvest seed can take a while, I’ve never actually taken much notice of how many weeks it takes from pollination until the seed is ready, it would be around four to six weeks, I will update here the time taken at a later date.
The old flowers have long fallen away from the now drying up sepals that encased and held the base of the flowers.
The ovary if fruiting and has swollen and is encasing some seed, note how the bottom fruit is larger than the ones above it. Canna flowers open first from the base and progress up to the top of the spike.
Not all garden canna plants produce seeds, most of the large floppy Italian style cannas such as Burbank Roma and Yellow King Humbert don’t produce seed but still they fruit up and swell, from a distance they appear as if they are setting seed but they are not they are false and sterile never to produce seed.
You can normally see the difference between a true seed setting fruit and a sterile cultivator, the sterile types still fruit up quite well but there are three indentation on the fruit, these indentations are around the three carpel’s which encase the ovaries, this I have noticed time and time again.
Fruit capsules not ready yet, they still has a fair way to go, the green will progress to a brownish tone and the little spikes on them will become brittle and easily fall off when handled.
Here I have opened up three fruit capsules and exposed one seed from each one, note how the middle capsule didn’t produce a seed in this carpel. The canna garden seeds are white and a little bit soft, exposed un-ripened seeds like this quickly harden up a fair bit and go darker in color quite fast when exposed to light and air.
A naturally ripe and ready fruit capsule, a sure indication that its ready to collect from is that it’s starting to split open, you can just see the black seed, another guide is to give a shake, ripe and ready to harvest seeds can be heard from within its casing.
Exposed and ready to harvest and collect for sowing.
I take the time to individually check each seed for good viability to help ensure a much better germination rate.
How to Check Canna Seeds
Pictures of Fertile Seeds