What Are The Fillers in a Bag of Fertilizer?

Understanding Fertilizer Fillers

Fertilizers play a crucial role in a lawn care program.  Fertilizers deliver essential nutrients to lawns.  

We often get asked a slew of questions from customers such as:  “Why didn’t my fertilizer absorb into my lawn?” “What are those pebbles left behind” “Is the fertilizer working if I still see it on the ground?”

While we completely understand the concern, you need not worry!  Often what you are seeing left behind is fertilizer fillers or carriers. 

What Are Fertilizer Fillers?

Fertilizer fillers are inactive ingredients that allow us to control and dilute the concentration of nutrients and products, they ensure that there is no clumping, they aid in even distribution, and they facilitate easier application.  

Purpose and Benefits of Fertilizer Fillers:

  1. Physical properties: Fillers can enhance the physical properties of fertilizers, making them more free-flowing, granulated, or pelletized. By improving the handling, fillers prevent caking or clumping, making it easier to apply.

  2. Nutrient Control: Certain fillers act as slow-release agents, helping to control the release of nutrients over time. This gradual release ensures that plants receive a steady supply of nutrients, reducing the risk of nutrient loss through leaching and minimizing the potential for fertilizer burn.

Types of Fertilizer Fillers:

  1. Inert Materials: Materials such as sand, clay, diatomaceous earth, and perlite are commonly used as fillers due to their low cost and availability. These inert substances do not contribute any significant nutrients but help to improve the physical properties of the fertilizer.

  2. Organic Fillers: Organic materials like peat moss, sawdust, and compost can serve as fillers. These materials may add some organic matter to the soil, promoting improved soil structure, water retention, and microbial activity. However, the nutrient content in organic fillers can vary, and they should be carefully selected to avoid introducing weed seeds or pathogens.

  3. Sulfur and Lime: Sulfur and lime are occasionally used as fillers in specific fertilizers. Sulfur can help acidify alkaline soils, while lime can raise the pH of acidic soils. These fillers provide additional benefits alongside the nutrient content of the fertilizer.

Since 2007, Green Meadow Lawn Care has provided homeowners throughout the greater Tolland, Connecticut area with premium fertilization programs, tick control, mosquito management, seeding & aeration and tree & shrub care. 

Visit our Learning Center to find out more about how our services can help you or visit our Youtube Channel to view more in our Learning Center Series.

To speak to our Customer Service Manager, please call Dave (view Dave's video bio here) with any questions. Dave has been in the industry for 30 years and is always happy to help with his expert advice.  

860-870-5700