Answer: The best way to improve soil is through the addition of organic matter over a period of years. You did the right thing by adding compost, but you'll need to continue to add it over the years in order to build up your soil so that it is a garden loam instead of hard dirt. Here's how:
Begin by spreading 4-5 inches of compost or other organic matter over the planting bed and diggng it in to a depth of 6-8 inches. Plant your perennials and annuals, then spread another 2-3 inches over the bare soil between the plant. At the end of the season dig this mulch into the soil and add some fresh organic matter over the bare soil. Repeating this on an annual basis will eventually improve the soil and make it a wonderful place to grow colorful plants.
Best wishes with your garden!
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