We are finally getting some crisp cold weather. Those warm season flowers of summer are all but dead at this point and should be pulled up. After pulling the old plants, you will need to prepare the soil.
Pull the weeds first. Add at least two inches of organic additives like chicken manure, compost, etc. Till the soil between eight and twelve inches deep. Sprinkle on your choice of fertilizer. Form the bed into a nice plateau and rake it smooth. For new beds, most cool season flowers want sun. Choose areas that are well drained and have a lot of sun. The more sun, the better.
If growing flowers from seed, read your seed packet closely to get the correct planting depth and spacing from other plants. Generally, the smaller the seed, the closer to the surface they are planted. If you accidentally plant too many seeds, thin them out when they start to grow. Overcrowding will make your plants under perform.
Use mulch. It prevents weed growth, deters fungus from spreading, and holds moisture in the ground. Keep your colors simple. Stick to one or up to three colors per grouping. Too many colors become distracting instead of interesting and enjoyable.
It is time to pick out your flowers that will last into spring. It is important to get those flowers into the ground so they can get established before the real cold season hits. Here are some nice flower choices for areas that get at least six hours of direct sunlight: calendula, delphinium, dusty miller, galliardia, geranium, holly hock, larkspur, nasturtium, ornamental cabbage, kale, petunia, poppies, snapdragon, statice, stock, sweet pea, and toad flax.
Sometimes you have a shady area that could benefit from some color. If you have an area that gets at least four hours of direct sunlight, try out the following flowers: viola, pansy, alyssum, diascia, and columbine. If you have an even shadier area that requires color, try out the following flowers: cyclamen, foxglove, primrose, forget-me-not, and lobelia.
Some cool season plants will bloom in fall, lose their blooms, and bloom again in spring. Think of these as getting double for what you paid for and enjoy the show. The extra root development will lend itself to much larger blooms in spring.