Starting Annuals from Seed Indoors
If you've got the space under grow lights or a very bright window, starting annuals early from seed can save a lot of money and give you earlier blooms. I also like having more control over the final placement in my garden than the scatter method allows.
I use shallow trays (repurposed take-out containers) and sterile seed starting mix. I poke a few holes in the trays for drainage. These trays can be washed and used many times before recycling and usually have lids that make nice germination domes.
I usually sow expensive seeds in individual seed blocks, but cheaper seeds, collected seeds, and really tiny dust seeds do well in mass planted trays. This time I sowed Marigold 'Jaguar', Zinnia 'dahlia flowered', Zinnia 'Green Envy', Cleome, Blue Lobelia 'Crystal Palace', Carpathian Harebell, Snapdragons, and English Daisy.
The larger seeds get covered with a thin layer of seed starting mix, I left the tiny seeds on the top of the soil and sprayed them with water. Then I put on the plastic cover and lowered the grow light.
Less than a week later the big seeds (Zinnia, Cleome, Marigold, and Calendula) were up and I removed the plastic lids.
The tiny seeds took about 2 weeks to sprout but are now looking good. I may go in and snip out some of the cleome with scissors - they ended up really close together. The others will be easy to tease apart when transplanting or plant in chunks.
You can also try wintersowing tender annuals, but wait until after your freezing temps have past. For the tender annuals it is more like "springsowing", the seeds don't require cold stratification and the mini greenhouses raise the soil temps to encourage germination and protect from frost. Read my cautionary tale of frozen zinnia seedlings.