Fertilizer Magic

Understanding the fertilizer analysis is essential to purchasing and applying the right kind of fertilizer. Fertilizers, such as 10-20-10, are identified on their package, by their analysis. The three numbers on the bag or container refer to the percentage of nitrogen, phosphorus, and potassium in the fertilizer.
Chemical fertilizers for the home garden are available in two forms. The granular form is sprinkled on the soil and worked in with a tiller or hand tool. Water soluble types are mixed with water and the feeding is accomplished by sprinkling onto the leaves of the plant (foliar feeding) or used as part of the watering process, in which the plant takes in the nutrients systemically (through the roots).
1. The first number in a fertilizer formula is the nitrogen content.....
Nitrogen is used by plants for producing leaf growth and greener, lusher leaves.
2. The second number in a fertilizer formula is the phosphorus content.....
Phosphorus is used by plant to increase fruit development and to produce a strong root system.
3. The third number in a fertilizer formula is the potassium (potash) content.....
Potassium is used by plants for flower color and size. It is also important to the strength of the plant.
For example, a 100 lb. bag of 10-20-10 converted to weight equates to 10 lbs. nitrogen, 20 lbs. phosphate, and 10 lbs. potash.

Before applying fertilizer to the garden, it is best to have your soil tested. This can be done with the use of reasonably inexpensive, home test kits, or by sending a sample to your local county or state agricultural agency. The soil test will tell you the level of nutrients already in the soil as well as the pH of the soil. (Nutrients may become unavailable to your plants if the soil pH is above or below a certain range.)
If your test is done by your county extension service, the test results will also provide recommendations for needed additions of lime and fertilizer.
The timing of the application of fertilizers is very important. Too much, or application at the wrong time, can lead to an overabundance of foliage, delayed flowering or plant death due to excess fertilizer salts around the roots, causing leaf and root burn. It is essential that you read and follow the product recommendations for fertilizers, or any other garden chemicals.