Milorganite vs. Lesco 46-0-0 (Turf Response)
Milorganite and Lesco 46-0-0 supply nitrogen in very different amounts and release it at different speeds. Milorganite is a lower-nitrogen fertilizer that usually feeds more gradually and contains iron. Lesco 46-0-0 is concentrated urea that can green turf faster, but needs careful measuring, even spreading, and label-directed watering. Compare nitrogen rates, not pounds of product.
A common mistake is to spread the same weight of each product and expect the same result. One pound of 46-0-0 contains far more nitrogen than one pound of 6-4-0. That mismatch can cause uneven growth or turf injury, especially if urea overlaps or is applied to dry, stressed grass.
The main difference: nitrogen concentration and release
Nitrogen is the main nutrient in these products that supports leaf growth and green color. The numbers on a fertilizer label show the percentage of nitrogen, phosphorus, and potassium by weight. Compare products by the nitrogen each delivers per 1,000 square feet, not by bag weight or spreader setting.
Milorganite commonly lists a 6-4-0 analysis and 2.5% iron, while Lesco 46-0-0 is a high-nitrogen urea fertilizer. Check the current bag label before use: product formulas and directions can change. The 4 in Milorganite’s analysis indicates phosphorus; the zero at the end means no guaranteed potassium.
| Comparison | Milorganite | Lesco 46-0-0 |
|---|---|---|
| Common guaranteed analysis | 6-4-0 | 46-0-0 |
| Nitrogen per pound of product | 0.06 lb | 0.46 lb |
| Product to supply 1 lb nitrogen per 1,000 sq. ft. | About 16.7 lb | About 2.17 lb |
| General response pattern | More gradual | Faster when urea dissolves and is taken up |
| Other listed nutrient | Commonly includes iron | No guaranteed phosphorus or potassium |
A product’s nitrogen percentage does not, by itself, tell you exactly how many days the lawn will take to respond. Temperature, soil moisture, turf condition, and irrigation all affect results. Milorganite’s iron may deepen green color, but iron is not a substitute for nitrogen and will not fix every cause of pale turf.
Choose by the lawn’s needs, not by color alone
The right product depends on how much nitrogen your lawn needs, how quickly you want a response, and whether conditions are suitable for fertilizing. A soil test, turf species, season, previous applications, and local fertilizer rules should guide the decision. Do not use either product to force growth on dormant or drought-stressed grass.
Choose Milorganite when its label and your nutrient plan suit a more gradual feed and its iron is useful to your lawn. Choose urea when you need a measured nitrogen application and can follow its label directions, including any watering instructions. Neither is automatically the better fertilizer for every lawn.
Before buying or spreading, check:
- Your lawn’s measured area and turf type.
- Recent fertilizer applications, including nitrogen already applied.
- Soil-test recommendations and any local nutrient limits or restricted periods.
- Whether the lawn is actively growing and has enough moisture.
- The current bag’s analysis, rate directions, and safety instructions.
Phosphorus deserves attention, too. Milorganite commonly contains it, while 46-0-0 does not guarantee phosphorus or potassium. If local rules limit phosphorus, or a soil test does not call for it, confirm whether Milorganite is permitted and appropriate for your site.
Calculate a fair, label-compliant rate
A nitrogen rate is the amount of nitrogen applied to a given area, often stated as pounds of nitrogen per 1,000 square feet. To find the product amount, divide the desired nitrogen rate by the product’s nitrogen fraction. Use the label and local recommendations to choose the nitrogen rate; the examples below only show the math.
Product rate = desired nitrogen rate ÷ nitrogen fraction
For a target of 0.5 pound nitrogen per 1,000 square feet:
- Milorganite at 6% nitrogen: 0.5 ÷ 0.06 = about 8.3 pounds of product.
- Lesco 46-0-0 at 46% nitrogen: 0.5 ÷ 0.46 = about 1.09 pounds of product.
For one pound of nitrogen per 1,000 square feet, the matching amounts are about 16.7 pounds of Milorganite or 2.17 pounds of urea. These are calculations, not universal recommended application rates. Do not exceed the bag directions or local limits, and include nitrogen from earlier applications in your plan.
Measure the turf area before calculating. If a lawn covers 5,000 square feet, multiply the product amount for 1,000 square feet by five. Leave out beds, paths, and other areas that will not be treated. If you cannot confirm the area or rate, pause rather than guess.
Spread evenly and reduce the risk of burn
Calibration means checking how much product your spreader releases over a measured area. Settings do not transfer reliably between products, spreaders, or walking speeds. Urea is especially easy to overapply by weight because it has a high nitrogen concentration. Read the spreader directions, then test output before treating the whole lawn.
- Read the current label and inspect the spreader. Make sure the hopper is dry and the gate works.
- Measure a test area and calibrate for the specific product, setting, and walking pace. Recheck calibration when any of those change.
- Apply to dry foliage in two perpendicular passes, each at half the planned rate, if the label permits. This can help even out coverage.
- Avoid overlap, pavement, drains, and waterways. Sweep or blow granules from hard surfaces back onto the lawn.
- Water in as directed on the label, especially after urea. Do not apply when heavy rain or runoff is likely.
Wear gloves, eye protection, and a dust mask when handling dry fertilizer. Keep children and pets off treated areas until the label’s re-entry directions are met. Store each product sealed in its original labeled container, dry and away from food, feed, children, and pets. Clean the spreader after use; damp fertilizer can cake and interfere with accurate delivery.
What response to expect, and when to wait
Urea usually provides a faster green-up and growth flush once it dissolves and the turf takes it up. Milorganite generally responds more gradually. Actual timing varies with weather, soil moisture, irrigation, and turf health, so avoid promising a fixed number of days or applying more because color has not changed immediately.
Fast growth is not always a benefit. After a nitrogen flush, grass may need more frequent mowing. Avoid removing too much leaf tissue at once, and watch for patchy color or unusual growth before deciding whether to fertilize again. Base the next application on the lawn’s response, season, soil-test advice, previous nitrogen, and local limits, not a fixed calendar alone.
Localized burn can follow miscalibration or overlapping passes. Concentrated, soluble urea poses added risk on hot, dry, or water-stressed turf. Heavy rain or excess irrigation can also move nitrogen off-site. If you are unsure that the spreader is calibrated, stop and check it before continuing. Never exceed the label rate to chase fast color.
Fair comparison examples from lawn-management decisions
These are practical comparison scenarios, not controlled research trials. They show how to choose and measure products; they do not predict a guaranteed color change. For a true side-by-side test, use similar turf areas, apply equal nitrogen rates, and keep other conditions as alike as possible.
Scenario 1: Comparing response on similar lawn sections. Mark two comparable patches and leave an untreated buffer between them. Apply the same nitrogen rate to each patch, using the correct product calculation and separate spreader calibration. Keep mowing and irrigation consistent, then record color and growth over time. Different light, soil, or watering can skew the result.
Scenario 2: A lawn that needs a more measured, gradual approach. If the lawn is actively growing and the label and nutrient plan support Milorganite, its lower nitrogen concentration means more product must be spread to reach a given nitrogen rate. Measure carefully and consider its phosphorus content when checking soil needs and local rules.
Scenario 3: A lawn where a faster response is the goal. If turf is actively growing, water is available, and the label and local guidance permit an application, urea may fit. Its concentrated nitrogen means the product amount is small, so calibration and even coverage matter. Avoid use on stressed turf or before runoff conditions.
Keep a simple record for each application: product and lot, area treated, nitrogen rate, spreader setting, weather, irrigation, and turf response. That record makes it easier to avoid stacking applications and to compare results honestly.
Conclusion: match the nitrogen rate to the product
Milorganite commonly supplies 6% nitrogen and iron, while Lesco 46-0-0 supplies 46% nitrogen as urea. That difference drives the product-rate gap and the greater need for precise measuring with urea. Check the current label, calculate from nitrogen percentage, calibrate the spreader, and observe the lawn before applying more.
Frequently asked questions
Is Milorganite or 46-0-0 better for a faster green-up?
Urea in 46-0-0 typically acts faster after it dissolves and is taken up. Timing depends on turf condition, temperature, moisture, and irrigation. Follow the label and avoid using a high rate to force color.
How much Milorganite equals one pound of nitrogen per 1,000 square feet?
At 6% nitrogen, about 16.7 pounds of product supplies one pound of nitrogen per 1,000 square feet. Verify the current bag analysis and make sure that nitrogen rate is appropriate for your lawn.
How much 46-0-0 equals one pound of nitrogen per 1,000 square feet?
At 46% nitrogen, about 2.17 pounds of product supplies one pound of nitrogen per 1,000 square feet. Check the exact label and do not treat this calculation as a recommended rate for every lawn.
Can I apply both products at the same time?
Do not combine or stack applications without calculating the total nitrogen and checking both labels and local rules. Account for earlier applications, too. Applying two products can raise the total rate beyond what the lawn needs.
Does Milorganite’s iron replace nitrogen?
No. Iron can affect turf color, but it does not replace nitrogen’s role in plant growth. Poor color can have many causes, so check turf conditions and soil-test guidance rather than assuming more iron or nitrogen is the answer.
Should I water after applying urea?
Follow the current product label. Watering may help dissolve urea and move it into the turf, but excess water or rain can increase runoff risk. Do not apply when runoff is likely.
Can fertilizer cause lawn burn?
Yes. Excessive or uneven fertilizer, including overlapping urea, can injure turf. Risk rises when grass is hot, dry, or water-stressed. Stop if spreader output is uncertain, and never exceed label or local limits.
Can I use the same spreader setting for both products?
No. Calibrate for each product and your spreader. Product size, flow, gate setting, and walking speed affect output, so a setting that works for one fertilizer may deliver too much or too little of the other.
(This article was written by one of our staff writers, Victor Dempsey. Visit our Meet the Team page.)
