Plants absorb a wide variety of elements throughout their lifecycle. In total, there are 16 essential nutrients that plants need to maintain healthy patterns of growth. If you’re new to cultivation, choosing a nutrient product for your garden can be a challenging task. However, understanding the contents of fertilizer can help influence purchasing decisions. For example, inspecting the guaranteed analysis can be a great way to determine whether or not a nutrient product would be beneficial in your garden. Read the passages below to learn how to read the guaranteed analysis on fertilizer. But first, read the section below titled, “General Nutrient Considerations”, to learn about the elements that are required to keep plants happy and healthy. 

General Nutrient Considerations

Plants in any environment need a vast array of elements to maintain periods of vigorous growth. In total, there are 16 essential elements necessary for healthy and deficient-free plant growth. These elements are separated into three categories called, macro, secondary, and micronutrients, and are typically combined at an adequate rate within liquid, powdered, or granular nutrient supplements. However, growers must be aware of the combination of elements within fertilizers – inspecting the guaranteed analysis can assist in fine-tuning a cultivator’s approach to fertilization. 

What is a Guaranteed Analysis?

Law requires that fertilizer manufacturers display the contents of liquid, powder, and granular fertilizers on the back of containers in the guaranteed analysis section. This basic label describes the percentage of macro (primary), secondary, and micronutrients in each formula. So, if you’re interested in learning more about the importance of reading the guaranteed analysis, follow the sections below for more information.

Important Terms:

• Micronutrients: Trace elements required in very small amounts. Includes iron (Fe), manganese (Mn), boron (B), zinc (Zn), copper (Cu), molybdenum (Mo), sodium (Na), cobalt (Co), silicon (Si), and nickel (Ni). 
• Secondary Nutrients: Calcium (Ca), magnesium (Mg), and sulfur (S). 
• Macronutrients: Nitrogen (N), phosphorus (P), and potassium (K). Important elements needed in the highest concentrations. Listed as the three numbers on the front of fertilizer containers- also referred to as N-P-K.

Why Read the Guaranteed Analysis?

Growers can reference the guaranteed analysis on the back of fertilizer containers to fine-tune nutrient enrichment and safeguard against nutrient toxicity and deficiencies. More than that, cultivators can inspect the different types of elements used in nutrient formulas to ensure they meet specific standards of quality. 

Reading the Guaranteed Analysis Examples:

Example #1: Cover Your Bases 

GP3 Micro, for instance, contains an aggressive amount of the primary macronutrient nitrogen (N), as well as a long list of trace elements like iron (Fe), manganese (Mn), boron (B), zinc (Zn), copper (Cu), and cobalt (Co). The nitrogen and micronutrient component of GP3 compliments the other two parts of the program beautifully. For example, GP3 Grow contains essential secondary nutrients such as magnesium (Mg) and sulfur (S), while GP3 Bloom is packed with highly concentrated sources of phosphorus (P) and potassium (K). The combination of these products gives plants a wide variety of micro, secondary and macro elements to uptake during periods of growth and bloom. 

Example #2: Select Specific Elements

Growers might reference the back of fertilizer to select elements needed in specific stages of growth. Read the passages below to learn how reading the guaranteed analysis will help you pick and choose what nutrients your plants absorb.  

Growers might reference the back of fertilizer to select elements needed in specific stages of growth. Read the passages below to learn how reading the guaranteed analysis will help you pick and choose what nutrients your plants absorb.  

Example #3: Quality Controlled Ingredients

Not all ingredients are created equal. So, if you’re on the hunt for the best raw ingredients, reference the guaranteed analysis and read the “derived from” section. Read the passages below to learn more about the benefits of inspecting the source of elements in nutrient formulations. 

GreenPlanet formulates its nutrients with the cleanest raw ingredients. Let’s take Hydro Fuel Grow A&B as an example. At the bottom of the guaranteed analysis, you’ll notice a list titled “derived from”. While the guaranteed analysis describes the percentage of elements contained within the formulation, the “derived from” section describes the source of the element. This is important for a few reasons. First, some elements, like calcium, have different grades that range in quality and solubility. Calcium carbonate, for example, is generally regarded as a low-quality source of calcium because of its insoluble nature. Hydro Fuel contains no carbonates, bi-carbonates, unnaturally derivatives, or fillers. However, it’s always a good idea to quality assure the ingredients you’re feeding your plants by inspecting the guaranteed analysis. 

Second, some nutrient manufacturers, like GreenPlanet, include multiple sources of high-quality ingredients. For example, Hydro Fuel Grow (A) contains three unique sources of chelated iron (Iron EDTA, Iron EDDHA, Iron DTPA). Not all brands include multiple sources of chelated metals. So, before committing to a fertilizer, refer to the guaranteed analysis to quality assure the ingredients going into your garden.  

Whatever your style of garden, chances are, GreenPlanet Nutrients has the perfect base nutrient program. To access the programs available at GreenPlanet Nutrients, contact a member of the GreenPlanet sales team, or your local garden supply store for product information and purchasing inquiries. 

Check out our Resource Centre for more product information

Read More

---

• 
  GROWING PAINS: How to Prevent Blossom End Rot in Tomatoes with Horti Late CalJuly 9, 2026
  Tomatoes are one of the most rewarding crops to grow, but they are also prone to several physiological disorders that can reduce fruit quality and
• 
  Feed Your Greens: A Fresh Take on Plant FertilizerJune 26, 2026
  If you are serious about growing strong, vibrant plants, you need more than water and sunlight. The right plant fertilizer can make the difference between
• 
  Organic vs Synthetic Nutrients: What’s Best for Yield, Flavour, and Sustainability in 2026?June 26, 2026
  Choosing the right nutrients for your grow can feel like navigating a minefield of opinions, especially when it comes to the ongoing debate between organic