Fastest bedding plants to grow from seed?

[paininthepoinsettia]

After looking online at bulk buys and spending lots of money I thought I might have a go at growing some plants from seed. As it's late (or is it?) I want something fairly fast germinating. I need plants such as trailing petunia, coleus, impatiens. How well do these do and what are the likely time frames from seed to being able to plant out? I have a few very sunny, warm windowsills, providing the weather keeps up.

Nasturtiums, Cosmos and marigolds germinate quickly. You can’t really put any annuals outside until the last chance of frost has gone. That will be sometime in May depending where you are in the country.

I grow nasturtiums, fast germination, easy to manage and the leaves are peppery and give a spicy zing to salads.

Marigolds