16-0-0 Double Dark 6% Iron - Bio-Nite - Granular Lawn Fertilizer - NC Grass Plugs
16-0-0 Double Dark  6% Iron - Bio-Nite - Granular Lawn Fertilizer
16-0-0 Double Dark  6% Iron - Bio-Nite - Granular Lawn Fertilizer
16-0-0 Double Dark  6% Iron - Bio-Nite - Granular Lawn Fertilizer

16-0-0 Double Dark 6% Iron - Bio-Nite - Granular Lawn Fertilizer

Regular price $44.99 $0.00 Unit price per
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16-0-0 Double Dark blend will do just what the name implies: make your lawn double dark green. It's really that simple - green and more green.

  • One 45 lb bag covers 15,000 sq ft
  • Analysis is 16-0-0:: N-P-K, plus 6% iron
  • Contains Urea for a darker green color
  • Great for greening up the lawn but won’t flush it with too much growth


Product Description:
First off, let's just point out that Double Dark contains 6% iron. There are very few granular fertilizers available that have this much iron in them. We all know that iron is the key to that dark blue-green color, but...Double Dark also contains 16% nitrogen because one thing that so many people forget is that iron won't work if the lawn isn't actively growing.

Think about it: the lawn has to be growing in order to take in nutrients and what element stimulates growth? Answer: Nitrogen The secret to Double Dark is that the nitrogen and the iron are working together. Search around and you will hear people who say, "I was using Ironite but after a while, it just stopped working." That is because there is no nitrogen in that product to keep things growing.

The nitrogen we put in Double Dark Blend isn't over the top - it's just respectable at 16% and, one-quarter of that N is slow release. You will get some green from the N too, but it's not going to smack your lawn in the face and make it flush out a bunch of top growth. The nitrogen is really just there to stimulate intake. 

You can also apply Double Dark in between your regular fertilizer applications if you just feel like you want to sling some fert!

For Warm-season turf will benefit from sustained “spoon-feeding” monthly in summer with this product.

Cool-season turf will benefit from added color without a strong surge from too much N.


All-Natural Bio-Nite™ in Every Bag!
Bio-Nite is a bio-solid filler we add to every bag of Double Dark Fertilizer. Bio-Nite is the same thing as Milorganite, but instead of being sourced in Milwaukee, it comes from South Florida. We can tell you that it “smells like a whole lot of success!” The good news for you is that the smell tells you that the included Bio-Nite is feeding microbes in the soil every time you apply and they love it!


Application Information:
Double Dark Fertilizer Blend can be used on the following grasses:

Cool Season Lawns - Kentucky Bluegrass, Turf Type Tall Fescue (all fescues), Ryegrass.
Warm Season Lawns - Bermuda, St Augustine, Zoysia, Centipede, Bahia.


A 45 lb bag covers 15,000 square feet

Application  Details

Apply at 3 lbs per 1,000 square feet of lawn area

Apply every 30-45 days

Can be applied at any time during the growing season for both cool and warm-season lawns

Water-In  Instructions

Apply to a dry lawn, and water into turf within the first 48 hours with 1/4" of rainfall or irrigation

Sweep excess off sidewalks and driveways to avoid staining


Product Resources:

Shipping costs

Included for most states within the U.S.

NO P.O. Boxes

State Restrictions

AK, HI, CA, WA, ID, and OR


Yes, free stickers with this item

Typical Delivery Time

4 - 7 business days

Product Type


Cancel | Return | Exchange

All sales are final, no cancellations, returns or exchanges


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