One of the best annuals of fall are marigolds. They last until frost and put on a sensational display. Since they are hard to find in garden centers in the fall, I grow them from seeds. I generally plant the petite ones, but the larger ones are great too. While mine are ready to set out, it is still not too late to sow some for your garden. I have never direct seeded at this time of the year. I see no reason it would not work, if you can keep the seeds damp and get them to germinate. Instead, I seed mine in cell packs and allow them to grow until they have a good root system and are hardened off to withstand the heat and sun (I do this by putting the cell packs in high shade until the seeds germinate, and then move them to a sunny location for at least a half a day). Once they are ready to be planted, I clean the bed out where I want to place them and work the soil well. Then, I space them out and plant them about 18 inches apart and water well. The reason for this spacing is because I seed cilantro between each seedling so we can enjoy this herb for cooking this fall. If you are not going to mix something with your marigold planting, then I would space the seedlings 8 to 10 inches apart. Once they are established in the bed and growing, I liquid feed them every two weeks until they start blooming. Fall marigolds are they best.