Understanding a Fertilizer Bag is Needed for Successful Gardening

Plant fertilizer is one of those topics that every gardener needs to review when planting a flower / vegetable garden or maintaining the lawn, trees and shrubs in the landscape.

There are many blogs and articles about the composition of fertilizers and hopefully this explanation will assist you when you are looking for products at your local nursery and garden centers.

This very basic description is applicable whether you choose to use chemicals or non-chemical soil additives to your  garden or home landscape.

There are major mineral elements needed for plant growth. The top three often forgotten are carbon (C), hydrogen (H), and oxygen (O) and are absolutely necessary for any plant growth to occur. Obviously they are only obtained by air and water and cannot be packaged in a chemical fertilizer.

Besides carbon, hydrogen, and oxygen, biologists have determined that there are essentially 6 additional macronutrients: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), which are required by plants in large amounts to thrive.

The other nutrients are referred to as trace elements (micronutrients) which are essential for some plants to grow and may be not quite so essential for  other plant varieties.  

All these mineral elements can be obtained naturally in varying quantities, however since the earliest days when man started to cultivate plants, he has been trying to achieve optimum plant growth by adding soil additives with higher percentages of both macro and micro elements. With today’s commercial horticulture, (farms,  tree nurseries, green houses, golf courses,  small garden plots, houseplants etc.) soil additives in the form of fertilizers are added to achieve optimum plant growth.

The top three nutrients in fertilizers are nitrogen (N), phosphorous (P) and potassium (K) and are collectively known as N-P-K. The N-P-K composition of a bag chemical fertilizer is listed on the outside of the fertilizer bag in are listed in the exact order of N-P-K.

Briefly:

Nitrogen (N) is a major factor in stem and leaf growth.  Too much nitrogen can delay a plant's flowering and fruiting. Deficiencies can  reduce  crop yields, or cause the  yellowing of  leaves and stunted plant  growth.

Phosphorus (P) is essential for flower and fruit formation. Phosphorus is applied close to the plant's roots in order for the plant to utilize it.

Potassium (K) is necessary for the formation of plant sugars, starches, carbohydrates, as well as plant root and leaf growth.   Potassium enhances the flavor and color on fruit and vegetable crops and is important for leafy crops.
　

With some fertilizers, you may find a description of the additional elements of calcium, magnesium, and sulfur which have been added. 　
　
　
The N-P-K combination is determined on the type of plants you wish to grow and that will be the discussion of the next blog.