Like Tabby, I've sprouted delphinium seeds indoors under lights. Commercial seeds germinated pretty well for me without stratification - say around 50% germination.
But then I would kill them with damping off by overwatering commercial, peaty soil mix (Jiffy-Mix). The stems turned very soft right at soil level, and the seedlings fell over and died. Fungus causes this, and it can happen even with soil mixes that were sterile when purchased - spores can blow onto a tray.
I solved that by watering less and using a faster-draining soil mix despite the advice on the Botanical Interests seed packet. (I add medium-coarse screened pine bark shreds.) A fan will also help the soil surface to dry out faster.
Then I would put young plants with 1-2 pairs of leaves out on the porch for hardening-off, and slugs would mow them down right to the soil level. Eventually I learned how to reduce the slug population, at least neat my seedling trays.
I finally got ONE adult to survive in the gorund, with a lot of slug-holes its very first year.
Last year it was 5-6 feet tall, bloomed and seeded beautifully. Want some seeds from just one plant?
Delphinium elatum 'Pacific Giant' from Botanical Interests
blooms are pale blue with light purple edges
OP heirloom Perennial, short-lived Perennial in Zone 2, 4 years in Zone 7 & warmer
needs stakes
Here was BI's germination advice:
heat causes dormancy
stratify 2 weeks
sow 1/4" deep in peaty soil - needs dark,
optimum germination at 50-55º F or 71-75ºF (two different sources)
emerge 14-28 days
slow & irregular germination
