University of Florida

Understanding Fertilizer Labels

Fertilizers can provide plants with nutrients that help them grow. But before you use it, it's important to understand the fertilizer's label. The label includes a series of numbers that indicate the percentage of nitrogen, phosphorous, and potassium, by weight. For example, a 16-4-8 fertilizer contains 16 percent nitrogen, 4 percent phosphorous, and 8 percent potassium.

The label also lists all of the other nutrients as part of the guaranteed analysis, and information about how to properly apply the product. The fertilizer label specifies if the fertilizer is water soluble or controlled release, indicating if the nutrients will be available immediately to plants or slowly over time.

Remember that you should apply only as much fertilizer as plants can use, and always fertilize responsibly.

UF/IFAS Publications

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