Emerald Lawn Fertilizer

10-0-20 · 45% Slow-Release · Iron & Micronutrients

Emerald delivers rich green color while helping established lawns build stronger turf and better withstand heat, drought, and everyday stress. Its high-potassium formula provides steady feeding without pushing excessive top growth.

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Proven ResultsProfessional-grade products

Made in the USAQuality ingredients

Expert SupportReal lawn experts to help

Keep Your Lawn Greener, Stronger & Ready for Tough Conditions

BUILT TO HANDLE TOUGH CONDITIONSHelp your lawn stay greener and stronger through heat, drought, and everyday wear.

Better Heat & Drought Tolerance

High potassium helps your lawn handle summer heat, dry spells, and stressful growing conditions while maintaining healthier turf.

A Richer, Deeper Green

Added iron and micronutrients help bring out a deeper green color, keeping your lawn looking healthy and vibrant.

Long-Lasting Feeding

With 45% controlled-release nitrogen, your lawn gets a steady supply of nutrients for weeks instead of one quick burst of growth.

Healthy Growth Without Excessive Mowing

The lower-nitrogen, high-potassium formula helps maintain healthy turf without pushing excessive top growth and constant mowing.

Keep Your Lawn Greener and Stronger Through Tough Weather

Hot summer days, dry weather, and everyday wear can be hard on your lawn. Emerald 10-0-20 Lawn Fertilizer helps your grass stay healthy, green, and strong when conditions get tough.

Emerald contains extra potassium to help your lawn handle heat and drought. It also includes iron for a richer green color and slow-release nitrogen that feeds your grass gradually without causing excessive growth.

A Greener Lawn Without All the Extra Mowing

Not every lawn needs a big boost of nitrogen. Sometimes it just needs the right nutrients to stay healthy.

Emerald provides steady feeding while helping your lawn stay strong through stressful growing conditions. It's a great choice for established lawns that need more strength and color without a big growth spurt.

Emerald or Almighty: Which Should You Choose?

Choose Emerald 10-0-20 when you want to help your lawn handle heat, dry weather, and other stressful conditions.

Choose Almighty 20-0-10 when your lawn needs more nitrogen to encourage greener, more vigorous growth.

Select Your Grass Type.

Slow-Release Nitrogen

45% XCU

Recommended Turf

Established Cool- & Warm-Season Lawns

Phosphorus

0% — Phosphorus-Free

Iron + Micronutrients

Contains Iron and Micronutrients for darker green color.

Application Rate

4–5 lb per 1,000 sq ft

Equipment

Broadcast Spreader

Apply at the Right Time

Every 6-weeks during the growing season.

After Application

Water in after application

Guaranteed Analysis

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Total Nitrogen (N)10.0%

8.0% Urea Nitrogen†

2.0% Ammoniacal Nitrogen

Soluble Potash (K₂O)20.0%

Sulfur (S)3.1%

Iron (Fe)2.0%

Manganese (Mn)0.18%

Zinc (Zn)0.04%

Boron (B)0.07%

Derived From:

Ammonium sulfate, Ferrous sulfate, Ferrous oxide, Ferrous sulfate, Iron oxide, Ulexite, Manganese sulfate, Manganese oxide, Zinc sulfate, Zinc oxide, Muriate of potash, Polymer-coated sulfur-coated urea, Urea

+4.5% Slowly Available Nitrogen from polymer-coated Sulfur-coated urea.

Spreader Settings

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Find the right starting setting for your spreader.

Spreader Manufacturer Spreader Model

Select your spreader to see the setting.

Use this as a starting point. Calibrate for your spreader, walking speed, and lawn area.

Spreader settings & calibration guide →

Documents & Labels

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Product Label

Is this lawn fertilizer safe for my lawn?

Emerald’s slow-release nitrogen reduces the risk of fertilizer burn when applied at the recommended rate. Overapplication can still damage the lawn.

How long will it take for the fertilizer to work?

Once your application is applied and watered in, expect 7-14 days to notice a difference. As the nutrients begin to work, you will notice the lawn growing and darkening up in color.

Can I use this on St. Augustine or Centipede lawns?

Yes. Emerald is phosphorus-free and safe for both. For Centipede lawns, alternate with a lower-nitrogen product like NutriGreen 0‑0‑4 to avoid over-fertilization.

Will it stain my concrete or patio?

Fertilizer with iron can stain hard surfaces, so always sweep/blow stray granules off immediately. Do not wash it off with water.

How long does it feed the lawn?

Emerald feeds slowly and steadily for up to 8 weeks thanks to the 45% slow-release nitrogen. We recommend re-applying fertilizer at 6 weeks to allow some overlap.

Customer Reviews

Overall rating: 4.561265 / 5 from 253 reviews.

AI Generated Review Summary

Emerald 10-0-20 Lawn Fertilizer offers a dark green color and healthy lawn with its slow-release nitrogen and potassium. Customers appreciate its coverage and results, though opinions on color and effectiveness vary. It's suitable for various grass types and requires careful application to avoid staining.

Summary topics

Product Results (25%): Based on a significant number of customers, they are very happy with the results of the product.
Lawn Appearance (10%): Customers loved how the lawn looked after using the lawn fertilizer, as well as its ability to cover the lawn.
Lawn Health (22%): A significant number of customers appreciated that the lawn looks great and has never looked better after using this product.
Lawn Coverage (4%): Customers keep praising The Emerald 10-0-20 for its ability to cover the lawn.
Lawn Color (5%): Opinions vary on the color, with some finding it nice and dark, while others did not get the color as promised.

Review topics: [].

Review highlights

"The lawn is a really nice dark green color." — Derek L.
"Grass looks really good will buy again." — Anonymous
"My lawn quickly came back to life lush and green." — Anonymous

Reviews

Works great! Every lawn can

"Works great! Every lawn can look amazing with the Lawn Synergy plan. You get exactly what you need when you need it. No more guessing and having to go to the store, at an amazing price."

— Glenda P. (5/5)

Zoysia loves Emerald

"The product is fantastic for early fall feeding. The picture was taken 6 days after spreading. Thanks"

— Guillermo G. (5/5)

GREAT!

"GREAT!"

— Marilyn B. (5/5)

Lawn looks great! Greened up

"Lawn looks great! Greened up nice. Looks so much more healthier then before."

— karen L. (5/5)

Zoysia lawn repair

"Attached are two photos, one of my front yard last fall after a sub contractor did a jack & bore. The second picture is end of July this year after adding plugs, pulling weeds and adding Lawn Synergy fertilizer per their schedule. I am totally pleased with the results."

— Gerald C. (5/5)

So far, so good! Will

"So far, so good! Will continue to watch over the next year for results"

— Craig A. (5/5)

"Grass looks great"

— John (5/5)

St Augustine fertilizer

"The jury is still out. I see no results yet!"

— David H. (3/5)

Really greened up nicely for

"Really greened up nicely for August…. I think the brown areas are rebounding…. . it’s gonna take some time…. . looking forward to see how everything greens up this fall…. Thanks"

— John G. (5/5)

I used this on my

"I used this on my centipede lawn in south Mississippi several weeks ago. All I can say is it works. If you are reading this review and have never used lawn Synergy before, I can tell you it is truly a professional fertilizer. Has been extremely Hot 99+ for the last two weeks and extremely dry. I have the greenest lawn in the neighborhood. It’s amazing. Yes I have sprinklers and yes I been using them but I feel like the reason my lawn looks so amass because of Lawn Synergy. I’ve used other fertilizer and in the past and clearly see da difference. It is a professional product that works great. Thanks Lawn Synergy!"

— Michael P. (5/5)

Q&A

My lawn is summer stressed and starting to go dormant. It’s also consistently 85 degrees. Can this be applied ?: Fertilizer should not be applied to a stressed lawn. It can still be applied when hot, but apply early in the AM or late in the afternoon avoiding the heat of the day. Water the product in well after applying.
Does the Emerald contain any weed killer qualities? I have some clover, not much but would like to know if I will have to apply weed killer separately?: The 20-0-10 Almighty Fertilizer does not contain weed control. Post emergent weed control products would need to be used separately.
my lawn in the summer gets sun all day long will this work on my lawn?: This is a great fertilizer choice to use of cool season grass types over the summer season.
Does it work on zenith zoysia grass: 10-0-20 is a great product to use on Zoysia sod as a winterizer fertilizer. During the summer growing season, I would recommend using the 20-0-10 Almighty for zoysia grass.
How long before / after mowing should Emerald be applied?: Emerald can be applied right after mowing. If you are planning to apply before mowing, make sure the product is watered in very well first and then mow once the lawn is dry.

Three bags of lawn care products from Lawn Envy, including North Star 20-0-10 fertilizer, displayed on a green grass surface against a dark green background.

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