Preparing the ground is by far the most important part of preparing a flower bed. Although bulbs, annuals and perennials vary in their needs, nearly all of them require fertile, well-drained soil. No matter how much care you put into your plants, if the soil conditions are poor you will almost certainly be disappointed with the results.
Pick a good spot for your flower beds. The beds need to be in an area with good drainage and no standing water even after heavy rains. They should not be located at a low point where runoff water flows. Your spot should also have the right amount of sunlight for your flowers. If you're planning on a mixture of sun- and shade-loving plants, pick a spot with mixed sun and shade.
Pull up any large weeds or decayed plants from your planting site. Turn the top 6 inches or so of soil over with a shovel to kill any plants at your current site and loosen the dirt. Remove any rocks or twigs you come across.
Add 3 to 6 inches of fully decomposed manure or organic compost and mix it into the top layers of the soil by turning it over with a fork.
Test your pH level with a pH test kit. According to Frostproof,com, the optimum pH level for most flowers varies between 5.0 and 7.5, depending on the species. If your soil pH is below this range, add limestone to raise it. If it is too high, add a sulfur-based soil acidifier to lower it. Follow the instructions on the soil additive.
Watch your planting site for a few weeks after you prepare the soil. Pull out any stubborn plants that spring up after your first weeding.