Milorganite
Original Slow Release Nitrogen Fertilizer
Best organic fertilizer for gardeners seeking consistent, low-maintenance plant nourishment.
Nourish your landscape with Milorganite Original Slow Release Nitrogen Fertilizer. This biosolids-based granular fertilizer provides consistent, long-term feeding for lawns, flowers, vegetables, trees, and shrubs. Its 6-4-0 NPK ratio delivers essential nutrients, including iron, promoting healthy growth. The slow-release formula minimizes nutrient loss and runoff, while its uniform granule size ensures even coverage when applied with a standard spreader. Manufactured in the USA, this organic fertilizer is suitable for all soil types and can be applied throughout the spring, summer, and fall growing seasons, contributing to overall soil health.
$14.99
Owner Satisfaction
4.6
/ 5
Category Rank
1939
/ 4425
#1939 in Fertilizers
Price vs Category Average
-76%
Below average
NPK Ratio
640
/ --
Who it's for
- Homeowners worried about damaging their lawn with over-application
- Gardeners seeking deep color without constant mowing
- Eco-conscious gardeners looking to improve long-term soil health
Who should skip it
- Sensitive neighbors bothered by temporary earthy smells
- Users wanting to minimize heavy lifting and storage space
- Residents living in regions with strict phosphorus runoff laws
Performance breakdown
Nutrient Longevity
Slow-release formula provides steady feeding without the risk of burning plants.
Application Versatility
Safe and effective for everything from delicate flowers to expansive lawns.
Spreader Compatibility
Uniform granule size ensures consistent coverage with standard broadcast equipment.
Soil Enrichment
Biosolids-based composition actively improves soil health beyond simple plant feeding.
Greening Efficacy
High iron content delivers a deep, vibrant green to turfgrass quickly.
Storage Stability
Shelf-stable formula remains effective even after long periods of storage.
Key Specs
NPK Ratio
6-4-0
Fertilizer Type
Biosolids Fertilizer
Release Type
Slow Release
pH Range
6.5 - 7.0
Organic Status
Organic
Micronutrients
Iron (typically 2.5% - 4.0%)
Form
Granular
Country of Origin
USA
Features
- Provides consistent, long-term nutrient feeding
- Slow release formula minimizes nutrient loss
- Enriched with essential iron nutrient
- Suitable for a broad range of plants
- Easy application with standard spreaders
- Organic formulation for soil health
- Uniform granule size for even coverage
- Shelf stable for indefinite storage
What customers say
Customers highly value Milorganite for its reliable, sustained lawn greening. The slow release formula consistently feeds turf, delivering deep color without the risk of burning common with fast fertilizers. This predictable performance makes it a trusted staple for achieving healthy, low maintenance results over several weeks. While some note a temporary earthy odor after watering and higher application rates compared to synthetics, the consensus favors its exceptional quality and safety. Users prioritize this sustained health and rich coloration over rapid, explosive growth, confirming its status as a preferred choice in lawn care.
Know before you buy
Yes, Milorganite is safe for use on vegetable gardens. Because it is a slow-release, organic-based fertilizer, it provides steady nutrition without the risk of burning your plants.
No, Milorganite has an NPK ratio of 6-4-0, meaning it contains nitrogen and phosphorus but no potassium. You may need to supplement with a potassium-rich fertilizer if your soil test indicates a deficiency.
You can apply Milorganite throughout the spring, summer, and fall growing seasons. Because it is a slow-release formula, it feeds your lawn consistently over time rather than providing a quick, short-lived burst of growth.
One of the primary benefits of Milorganite's slow-release formula is that it will not burn your lawn, even if you apply more than the recommended amount. It is a very forgiving product for those new to lawn care.
Milorganite has a neutral pH range of 6.5 to 7.0, so it will not significantly alter your soil's acidity or alkalinity. The added iron is included primarily to help promote a deep, green color in your lawn and plants.
Yes, Milorganite is shelf-stable and can be stored indefinitely as long as it is kept in a cool, dry place. Ensure the bag is sealed tightly to prevent moisture from clumping the granules.
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