Amend the soil where you intend to plant your cool-weather bedding plants with rich compost. Spread 1 to 2 inches of compost on top of the soil and work it into the ground with a shovel or hoe to a depth of 3 to 4 inches. This will enrich the soil and help with drainage.
Add a slow-release, equally balanced fertilizer to the area you added the compost to. Follow the instructions on the package for the proper amount. Use a shovel or hoe to work the fertilizer into the soil, also to a depth of 3 to 4 inches.
Plant your bedding plants so the roots are no deeper than when the plant was in the container. The width of the planting hole should be slightly wider. Pat down the soil around the plant to elevate air pockets and ensure good contact between roots and soil.
Add mulch over the soil, around the plants, but keep the mulch away from the base of the bedding plants. Mulch will help keep the soil evenly moist, but when it is against the base of cool-weather bedding plants, mulch can create fungus and rot.