I will grow them in the garden pot in North Illinois. The soil is soft and moist outdoors now. When do I need to put the seeds into the soil, please?
The same question about the marigold seeds, please.

Too early they will sprout and then freeze unless you can cover the pot or bring it inside when it gets below freezing.
Marigolds planted in ground will come up when the temperature is right .
Nasturtiums can be started inside in a cup then planted out after frost freeze is past
If you have plenty seeds you can try some in the pot around April 15 and see what happens , replant if they get froze off.

Good luck and Great gardening

Cinda,
Thank you so much!

How about fragrant sweet peas seeds: same schedule, please?

Sweet-peas can handle cold soil temps and could be planted earlier
I will plant mine the 1st of April soak the seeds overnight , they will germinate sooner.

Oh you might want to protect your pea seeds till they come up , I have problems with ? (rodents) digging and ?eating the seeds before they can sprout.

Legume innoculant offends the squirrels here so I toss sweet pea seeds with it before planting them. The seeds do not need the innoculant ,but just to keep critters off. Maybe cedar oil would work also?