You can also direct-sow wildflower mixes or poppy seeds at Thanksgiving. These flower seeds need to be chilled by the cold, and don’t transplant well if you try to start them indoors, so sowing directly in the spot where you want them to grow is both the best and the easiest option. Make sure to prepare the soil by raking away any leaves or loose debris, loosening the top layer of soil by tilling, hoeing, or just raking if the soil is loose enough, then smooth out the surface with a hard rake. Mix the seeds with sand in a 1:4 ratio to make it easier to spread the seeds evenly, then sprinkle a very thin layer of soil or compost on top (no more than 1/8 of an inch!). Water lightly, and then leave it until spring! It’s ok if leaves cover up the bed over winter. When temps get above 55 degrees in the spring, you can remove any leaves to expose the dormant seeds to light. Try to remove weeds that come up, but make sure you know which plants are weeds and which are young flowers.
For great resources to learn more about wildflowers and to buy seed mixes, try American Meadows or Prairie Nursery.