Soil Nutrients

• Impatiens require nutrients from both supplemental fertilization and from the soil. Amending the soil prior to planting improves upon those nutrients already in the garden bed. Compost, either homemade or purchased, provides organic matter and trace nutrients to the bed. Work a 1- to 3-inch layer of compost into the bed prior to planting the impatiens, so the flowers draw the nutrients from it. Compost also adds aeration to the bed, and prevents fertilizer nutrients and water from leaching out of the soil too quickly.
  
  

Fertilizer Nutrients

• Commercial fertilizers contain nitrogen, phosphorus and potassium, indicated by the N-P-K ratio listed on the package. Most fertilizers also contain small amounts of other trace nutrients, such as magnesium and zinc. As flowering plants, impatiens needs more phosphorus than nitrogen or potassium. The phosphorus, indicated by the center number in the ratio listing, aids flower bud production and leads to lush blooming. A fertilizer formulated for flowering plants typically has a ratio of 5-10-5 or similar.
  
  

Bedding Application

• Use a slow-release fertilizer for impatiens planted in flower beds. Slow release fertilizers come as a granule that breaks down and releases nutrients slowly over a two- to three-month period. Apply 1 tsp. of a 5-10-5 or similar ratio fertilizer to every square foot of flower bed before you plant. Reapply the fertilizer every two months through late summer. The slow release of the nutrients ensures the impatiens have access to them as needed throughout the growing and flowering season.
  
  

Potted Plant Application

• Container-grown impatiens require more frequent fertilizer application. Potted plants need watering every one to two days, since the limited soil volume causes the plants to dry out quicker. This frequent watering causes the nutrients from a slow-release fertilizer to wash out of the pot before they are fully released into the soil and used by the plant. A soluble fertilizer makes the nutrients available to the plant immediately, but it also requires more frequent application. Applying a 5-10-5 soluble liquid fertilizer every two weeks to the potted impatiens throughout the growing season ensures the plants have access to the necessary nutrients at all times.