10 Best Organic Lawn Fertilizers 2025 in the United States

O.M. Scott & Sons Natural Grass Food is a natural fertilizer designed to nourish lawns for up to 10 weeks after a single application. Its nutrient sources come from nature, avoiding synthetic chemicals, which makes it a safer choice for households with kids and pets. It’s formulated to work well with all grass types and is easy to apply in granular form. You just spread it over your lawn and water immediately to activate the feeding process.

This fertilizer is compatible with most soil pH levels, fitting a variety of lawn conditions without causing harm. The nutrient release is gradual, lasting up to 10 weeks, so frequent reapplication is not necessary. One of the environmentally friendly features includes recyclable packaging and the absence of harmful additives, reducing impact on the ecosystem. The coverage of 2,000 sq. ft. per bag is suitable for medium-sized lawns, and the two-pack offers good value for consistent lawn care.

Although the product does not specify an exact N-P-K ratio, it provides essential nutrients to support healthy grass growth. Users seeking specific nutrient balances might find it less straightforward to compare with other fertilizers. Additionally, some may notice that results develop more gradually compared to synthetic options. This fertilizer is ideal for homeowners wanting a natural, easy-to-use solution for maintaining a healthy lawn without harsh chemicals.

The Sunday Green Machine Fertilizer is a liquid lawn fertilizer designed for easy at-home use, covering up to 10,000 square feet per two-pack. Its N-P-K ratio is 22-0-3, meaning it offers a high amount of nitrogen for promoting lush, green grass and some potassium, but no phosphorus. The nitrogen source is enhanced with natural ingredients like seaweed and iron, which support deeper root growth and overall lawn health, aligning well with organic lawn care principles. Application is simple and convenient—just attach the pouch and sprayer to your hose and spray your lawn, making it a good choice for those who want fast, straightforward feeding without messy granules or complicated spreaders.

The liquid form generally means nutrients are readily available for quicker absorption by the grass, but may require more frequent applications every 4 to 6 weeks, especially during active growing seasons. It is best suited for lawns with neutral to slightly acidic soil pH, which is typical for most grasses. The formula avoids harsh chemicals, which reduces environmental impact and supports a healthier lawn ecosystem. However, since it lacks phosphorus, it might not be the best choice if your soil needs phosphorus to improve root development or repair damaged areas.

Because it’s liquid and applied with water, runoff during heavy rain could be a concern if not applied carefully. Sunday Green Machine serves well homeowners seeking an easy-to-use, nitrogen-focused organic fertilizer that encourages greening and root health without synthetic additives. For those needing a more balanced nutrient profile or slower nutrient release, other alternatives might be more suitable.

O.M. Scott & Sons Natural Grass Food is designed as an organic fertilizer that feeds your lawn naturally and safely. It uses nutrient sources from nature without artificial chemicals, making it safe for people and pets when applied correctly. The product covers up to 2,000 square feet with one 12.72-pound bag and starts feeding grass immediately after watering, continuing for up to 10 weeks. This slow nutrient release helps maintain steady growth without overwhelming your lawn.

It’s suitable for all grass types and works in various soil pH levels, providing flexibility for different lawn conditions. The granulated form is easy to apply by spreading across the lawn. One nice environmental touch is the recyclable paper packaging, which reduces plastic waste.

If you want a straightforward, natural option that supports gradual lawn improvement and is pet-friendly, this product fits well. It may not deliver the rapid greening effect that synthetic fertilizers can offer.