How soon can I plant seeds after harvesting?

[NicoleJean]

I just collected mature Marigold, Petunia, Snapdragon, and Zinnia seeds from my plants. I dried them for a week in an envelope and than planted them in mini pots to see if they will germinate. I am just testing them to see if they are worth keeping and attempting to plant next spring. They are outside, it has been 70+ F degrees everyday and its been a week now and nothing is even sprouting. I also planted some seeds I bought in a packet at the store and most have already sprouted. How can I know if these seeds I am collecting are viable. I don't want to plant hundreds of them next spring just to have nothing come up and than have to go out and buy new seeds and end up with a late start. Do I have to wait longer than a week after harvesting before I can plant them? is there any tricks or secrets that I should know about? What could I be doing wrong?

[Ozark Lady]

Some seeds, and I am not sure about the ones you named, require a cold period before they will break dormancy.
Try putting some in the frig for a couple days and try again.

[Kisal]

What I have done in the past, when in doubt about the viability of seeds, is to put 10 or 20 of them between a few layers of damp paper towels. Keep the towels moist, but not soaked, and wait for however long it usually takes for seeds of that species to sprout. It isn't perfect, but it will give you an idea of the kind of germination rate you can expect.

If you put 10 seeds out, and only 2 sprout, then you'll probably get a germination rate of 20%. IOW, 20 out of every 100 seeds are likely to sprout when you plant them. OTOH, if 9 out of the 10 seeds sprout, you can expect a germination rate of about 90%.

Marigolds usually sprout within a week to 10 days after being planted, I think.

What kind of marigolds did you collect the seeds from? I have read that the seeds from the African-type marigolds ... those are the taller varieties with the big flowers ... are usually sterile. The marigolds with smaller flowers are called French marigolds, and they should be fine. If you started with a hybrid variety, however, the plants that grow from the seeds you saved very likely won't look exactly like the parent plants.

[NicoleJean]

Thanks! I am going to try all of the things you both sugested. The Marigolds are French mix and not hybrid. I bought those as seed packets this year. The Zinnia is also a mix I bought from packet and not hybrid. The snapdragons I am not sure. I bought 3 plants at the nursery this year and I collected seeds from those. I also bought the petunias as a plant but they are most likely hybrid since almost all petunias are. I am going to try the paper towl sugestions and if that doesnt work Ill try refridgerating for a week and than try replanting. I still have a month and half of nice weather left so I hope I can figure it out by than.