Provide your flower bed with the soil nutrients it needs to support lush foliage growth and an extravagant display of blossoms. Although specific nutrient requirements may vary slightly by flower species, all annual and perennial flowers benefit from general fertilization guidelines. A well-fertilized plant doesn't just grow faster, but it is also healthier and able to better resist various plant diseases and pests.
Spread fertilizer onto the surface of the flower bed while preparing it for planting. The University of Connecticut recommends using any fertilizer in which the nitrogen level is the same or lower than the amount of phosphorus in the fertilizer. Example products include a 10-10-10, 5-5-5 and 5-10-5 product. Apply according to its labeled guidelines, as application rates vary by the nutritional potency of the product.
Use a spade to thoroughly mix the fertilizer into the top 6 inches of the bed, then plant the bed with flowers.
Fertilize the flower bed again two months after planting for both annuals and perennials, according to the University of Connecticut. Spread the fertilizer around the established plants, scratching it into the soil surface but not mixing it deeper, as this may damage the flower plants' roots.
Water the flower bed thoroughly to moisten the soil to a depth of 6 inches. This helps carry the fertilizer nutrients into the dirt to immediately feed the plants, and also reduces the chance of burning the plants.