Larry A. Sagers Regional Horticultural Specialist Utah State University Extension Service Thanksgiving Point Office © All Rights Reserved
Could you please explain the differences between the many different kinds of fertilizer I see for sell and which ones are best?
There are many types of fertilizers and many ways to apply fertilizer. To get the best plant growth, fertilize as needed. For most plants follow a recommended and regular fertilization schedule, rather than waiting until your plants begin to suffer.
When you look at a fertilizers label , you will see three numbers listed. These three numbers refer to nitrogen, phosphorus, and potassium. If the label says it is a 10-10-10 fertilizer, that means that the fertilizer contains 10% nitrogen, 10% phosphorus, and 10% potassium. The other 70% is usually a mixing agent that allows the even spreading of the fertilizer.
Complete fertilizers contain the three primary nutrients mentioned above in varying percentages. A caution about complete fertilizers – they can cause a phosphorous buildup. Always read the instructions carefully and apply as recommended.
The following identifies the general types of fertilizers.
Comes in granules, powder or pellets Can be scattered or worked into the soil Partially soluble, dissolves over time
Used as a spray to the plant’s leaves Allows the leaves to absorb the nutrients directly and immediately May damage leaves when used in hot weather
Liquid Fertilizer Made up of soluble granules that are mixed with water Can be applied to the leaves or soil during watering Can be used with drip irrigation systems Provide immediate nutrients to the leaves and roots
Made up of dry or encased granules that last from 3 – 14 months Release nutrients over time with specific conditions Eliminates the need for more frequent feeding
Contains specific nutrient blends for particular plants Created specifically for the nutrient and application needs of a particular plant
Natural Organic Fertilizers
Created from materials derived from plants or animals such as manure, bone meal or fish emulsion Usually contain significant amounts of only one major nutrient Relatively slow-release Generally low in nutrient content