How Best to Fertilize an Established Flower Bed

Fertilize the Soil

• Every flowerbeds require deep, quick-draining soil, which gives the flowers a loose foundation with good moisture retention and nutrition. Mix 2 to 3 inches of organic compost into the soil every spring.

Spring Fertilizer

• Fertilize established flowerbeds every spring to increase the nutrition in the soil and encourage spring and summer blooming, suggests the University of Purdue. Apply 2 to 3 lbs of 5-10-10 fertilizer per 100 square feet of planted ground.

Application

• Broadcast granules of slow-release granular fertilizer, or side dress their flowers by mixing the fertilizer into the top 1 inch of soil around each plant.

Individual Plants

• Plants such as roses require fertilization throughout the summer. Gardeners should research their flowers and feed them per their independent needs. All-America Rose Selections advises to stop feedings two months before the first frost. Late feedings result in late perennial growth that will die with the first frost.

Mulch

• Maintain a consistent mulch layer around flowers to keep the soil warm and moist. As this mulch layer breaks down, it acts as a consistent source of compost and adds nutrition to the soil. Mulch is an easy way to make sure that flowers have a constant source of moisture, warmth and nutrition during the growing season.