10 Best Organic Lawn Fertilizers 2025 in the United States

Milorganite Recycled Lawn and Garden Nitrogen Fertilizer is an excellent choice for users looking for an organic lawn fertilizer option. One of the main strengths of Milorganite is its low-salt formula, which is gentle on plants, preventing dehydration and stress. This makes it suitable for a variety of climates and conditions, including peak heat periods. It's versatile enough for use on lawns, edible gardens, and houseplants, offering broad application possibilities.

The product is enriched with naturally occurring iron, contributing to a vibrant, green lawn without staining concrete or walkways, which is a significant advantage for maintaining aesthetics. With consistent nutrition lasting up to 10 weeks, Milorganite reduces the frequency of applications, which is convenient for users. Moreover, its even-release formula ensures uniform growth, helping achieve a lush and full lawn.

However, at a weight of 32 pounds, it might be cumbersome for some users to handle. The coverage area of 2500 square feet is decent, but users with larger lawns might need to buy multiple packages, which could be less cost-effective. The granule form is easy to apply, but it may require a spreader for even distribution, adding to the initial setup cost. Milorganite's use of recycled organic material aligns well with eco-friendly practices, though users should be aware of the potential variability in nutrient content typical of recycled products. Milorganite is a reliable, environmentally-friendly fertilizer that suits a range of gardening needs, though its weight and the potential need for additional equipment might be minor drawbacks for some users.

The Organic Plant Magic - Truly Organic™ Slow Release Granular Lawn Fertilizer is designed to cater to various lawn types, including Bermuda and St. Augustine grass. It offers a truly organic solution enriched with amino and humic acids, beneficial biology, and complete nutrition, which are essential for healthy lawn growth.

Its slow-release granules ensure a sustained nutrient supply, promoting long-term soil and grass health without the risk of over-fertilization or burning the grass. The application method is straightforward with a user-friendly chart, and its granules are compatible with all spreaders, making it easy to apply. This 20-pound bag can cover up to 5,000 square feet, making it an economical choice for larger lawns.

Additionally, it's safe for kids, pets, and the environment, featuring non-toxic ingredients that contribute to environmental sustainability. This fertilizer is a robust option for those seeking an easy-to-use, environmentally friendly solution for maintaining a lush, healthy lawn.

The Milorganite All-Purpose Eco-Friendly Slow-Release Nitrogen 6-4-0 Fertilizer offers a convenient solution for those looking to enhance their lawns, flowers, and gardens organically. With an N-P-K ratio of 6-4-0, it primarily focuses on providing nitrogen, essential for robust plant growth. One standout feature is its eco-friendly nature, ensuring that it does not burn your lawn or plants even in extreme weather conditions, thanks to its low salt content. This makes it particularly beneficial for maintaining healthy foliage without the risk of damaging your greenery.

The slow-release formula is another significant advantage, as it provides nutrients for up to 8-10 weeks, reducing the frequency of application and ensuring a steady supply of nutrients over time. Additionally, the inclusion of organically complex iron helps in achieving a deep, vibrant green lawn without staining concrete surfaces, which is a common issue with some synthetic fertilizers. However, the fertilizer has a relatively low phosphorus content (4) and no potassium (0), which may not be ideal for all soil conditions or plant needs. It’s more suited to established lawns and plants rather than new growth which might need a more balanced nutrient mix.

The product covers up to 2,500 square feet, making it suitable for medium-sized lawns and gardens. Considering its broad application method and soil pH compatibility, it's a versatile choice for gardeners seeking sustainable and effective lawn care. Those requiring a higher potassium or phosphorus content might need to supplement this fertilizer with additional products.