To begin with, species daffodils can be pollinated and produce seed. You'll recognize the seed pods as lumpy -well pods -that turn harder and brown after the flowers have faded.
Where is the seed pod?
The pod will be formed behind the flower so this means that once the flower has faded, do NOT cut off or deadhead the stem.
Do All Daffodils Produce Seed Pods?
In my experience - no.
Some of the doubles and "weird" flower shapes do not seem to set seed readily.
But most do.
When Do I Harvest the Seed
The easiest time is to wait until the pod just starts to shrink or shrivel up a little after it has turned brown. Some of them will even start to open up from the end - this definitely means they are ripe.
This usually means the seed is mature. Remove the seed from the pod to plant.
What Do I Do Then?
I usually keep the seed cool and dry for a month or so and then sow the seed in a baggie half-filled with damp vermiculite. I put this in the frig crisper so it stays cool and damp for 90 days.
I then simply put the seed into a pot filled with good, weed-free soilless mix soil (like Promix), barely cover the seed, water with luke warm water, and let it germinate at room temperature.
Sometimes you don't even have to use the pre-cooling but can simply sow them in pots in the spring. You wont get as high a germination this way but it does work for some of the seeds.
The seed will look like bits of grass.
How Do I Grow Them Up?
The easiest thing is to devote a section of garden to them. Treat them as if they were tiny, tender onions (pretty much they way they are). Handle carefully and transplanting the daffodil seed at the same depth they were in the pot.
No weeds allowed in this garden area!
Use gentle compost tea and compost for fertilizers.
Do not let them suffer from too much drought the first year. In fact, the first few weeks after transplanting, I wouldn't let the soil dry out too much at all -remember they are very shallow rooted.
Good strong sun although noon shade is great for the very early seedlings to protect them from drying out.
When Do They Bloom?
If you have fertile soil and take good care of them, you can expect to see small blooms in the third year. But the fourth year is likely.
Shopping Resources for this Page
A wide variety of daffodil bulbs can be found here (including "King Alfred Daffodils" :-)
Flower Gardening with Spring Bulbs Ebook
Doug's Ebooks Can Be Found Here