Every time you turn over soil in a vegetable or flower bed, add an inch or so of compost. Over time, the soil will improve until it looks like chocolate cake. In addition, mulch the flowers or vegetables with an inch of compost, perhaps covered with another mulch to prevent drying out.
One of the best times to use compost, especially if your supply is limited, is when you’re transplanting flowers, vegetables, and other small nonwoody plants. Adding compost to the planting hole gets smaller perennial plants off to a good start. Compost is particularly valuable for perennial food plants, such as asparagus, rhubarb, strawberries, raspberries, and blueberries. Annuals also benefit from a dose of compost at planting time.
When you dig the hole, throw in a handful of compost before positioning the plant. The compost provides nutritional support throughout the season, and it improves the soil structure around the plant. If you make it a practice to add compost whenever you plant, you’ll greatly improve the soil over time. Areas where annuals are set out every season will have especially good soil after a few years.