Fertilizer and Plant Nutrition

Violet Food is a fertilizer specifically labeled for African Violets. A good Violet Food should have approximately equal amounts of the primary nutrients, nitrogen (N), phosphorus (P) and potassium (K).These elements are normally found on the front label and will appear, for instance, as which is the recommended formula for standard African Violets, such as those grown in 3-inch pots or larger. Miniature and super-miniature African Violets, such as those grown in 2-inch pots or less, will typically need a slightly different formula. For those growing Optimara miniatures, a Violet Food or Miniature Plant Food with a NPK is recommended.

Aside from making sure your Violet Food has the correct NPK, it is important to consider the source of the elements. Many fertilizers which have been labeled for African Violets, in fact, contain impurities which can be harmful to Violets.

Urea, for instance, is a commonly used source of nitrogen. While it is often cheaper to use than other sources of nitrogen, urea is known to cause Root Burn on African Violets. The damage caused by Root Burn reduces an African Violet's ability to properly absorb water and nutrients. The most obvious signs of this are pale leaves and diminished flowering. Therefore, when selecting a fertilizer suitable for African Violets, make sure that it does not contain urea nitrogen. This can easily be determined by looking at the Guaranteed Analysis on the fertilizer label. If urea nitrogen is used, it will be listed.

When choosing a Violet Food, make sure that it is 100 percent water soluble. This is important for two reasons. First, if your Violet Food is not 100 percent water soluble, your African Violet may not be able to absorb all its elements. Second, unless your Violet Food is 100 percent water soluble, you cannot use it in a self-watering device. When using one of these devices, elements will only be drawn into the soil if they are fully dissolved.

The primary nutrients, nitrogen (N), phosphorus (P) and potassium (K), represent three of the 16 essential elements needed by African Violets and other plants for normal growth and reproduction. The other 13 essential elements are boron (B), calcium (Ca), carbon (C), chlorine (Cl), copper (Cu), hydrogen (H), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), oxygen (O), sulfur (S) and zinc (Zn). Of these, calcium, magnesium and sulfur are sometimes referred to as secondary nutrients or elements, while carbon, hydrogen and oxygen are often called the free elements, since these are normally obtained from the air and water