Seed will germinate after 90 days moist, cold stratification at 4 degrees C (38 degrees F). The seed of golden Alexanders germinate at high percentages. The resulting seedlings can be transplanted into containers by midsummer; and plants will be at flowering size by the following spring.

From: How to Germinate Zizia, USDA/NRCS Plant Fact Sheet. No mention of any light requirements but since it is a member of the carrot family and since it readily re-seeds itself I would surface sow the seeds or only barely cover as with other members of the same family.

Dave

Zizia seeds need full sun to partial shade, and the soil should be moist and muddy. It contains some rocky materials. Disease of any kind is rarely a problem for this plant.

I think the OP was referring to light requirements for germination rather than the sun exposure needed for growing on. Some seeds require light exposure to germinate, most do not.

Dave

Ontario Rock Garden database (where the more obscure types can be found sometimes) suggests the small seeds for these should be surface sown as Dave mentioned. Fall sowing is usually most carefree, and once established, the plants should continue to self sow reliably.

Dave is right. I had looked in an online database and it did not list requirements for Zizia but did say fennel needed darkness; since that is another member of the carrot family, I wondered if Zizia also needed darkness. I will play it safe and cover the seed shallowly.

I cannot find Zizia aptera plant anywhere except Prairie Moon Nursery, which is closed for the season.

The germination process for this plant is long and laborious -- involving stratification in sterile sand.

Furthermore, the seeds are miniscule.

If anyone has extra plants I would be interested in discussing with you buying several of them.

Thanks.

I have started Zizia aurea from seed (received in a trade and then winter sown), got one sprout, and after a couple years it has produced 1 seedling so far.

I received a division of Z aptera in a swap 5 years ago and it has self-sown 5 or 6 small seedlings in the garden, however, that garden bed is now grown up with perennials, so it is difficult to locate and confirm the seedlings. Jock feel free to email me in the fall and I can see if there are extra seedlings.