Fall & Winter Planted Flowers
Best: Sow wildflower seeds directly outside in the fall. This lets the weather and all the moisture, temperature fluctuations, and other climactic conditions do its work on them. They will sprout in the spring when and if they are ready.
Good: Put your seed packets outside in the fall or early winter, or place the seeds in a bucket of damp sand outside in the fall or early winter, and then sow them in the spring as soon as the ground starts to thaw.
OK: Store your seeds in damp sand in the refrigerator for a 4-8 weeks before planting. This will mimic winter but will not allow the temperature fluctuations and varying moisture that can help the seeds know when the time is right to sprout in spring.
*If you are unsure of what they look like when they sprout, consider sowing the seeds in rows so it is easier to see where you are expecting the sprouts to be.
*The NRCS Plant Database is a great resource for finding additional information and tips for germinating and growing many different types of native wildflower seeds.
*Sow seeds that are hardy in your zone. If you are unsure what plant hardiness zone you live in, you can check out the USDA's Plant Hardiness Zones map. Looking at what plants grow wild around you will also help you understand what grows well in your area.
*Sow a larger diversity of species than you otherwise might, to allow what suits your place best to take hold. Sometimes after a species that can really rock it in your area is there for a year or two, it can provide protection or other subtle encouragements to additional species to join it in your yard.
For a deeper explanation of wildflowers, please read Thinking Like a Wildflower, by Casey O'Leary.