12-12-12 Starter Fertilizer 3% Iron - Bio-Nite - Granular Lawn Fertilizer by Yard Mastery

$39.99 $44.99
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"Starter Fertilizer Fixes Everything!" This 12-12-12 is your go-to for seed/sod or general feeding, formulated specifically for DIYers.

  • Covers 6,000 sq ft (18 lb) - OR - 15,000 sq ft (45 lb)
  • Analysis 12-12-12:: N-P-K
  • Contains 3% Iron + Bio-Nite™
  • Great for seeding/sod installation

Product Description:
The Yard Mastery Starter Fertilizer contains 12% nitrogen, utilizing premium nitrogen source ammonium sulfate which brings a really nice steely-blue-green color to turf and interacts well with the other elements in the overall blend.

This blend also contains 12% phosphorus, which is plenty to push roots in an existing lawn or stimulate rooting in your seed, sod, plug, or spring project.

Rounding out the macros is 12% potassium. Here we have opted for the premium formulation, sulfate of potash, known to have a lower salt index.

As with all Yard Mastery blends, we have also included a nice amount of iron at 3% and a smattering of other micronutrients including boron, copper, manganese, molybdenum, and zinc.

All-Natural Bio-Nite™ in Every Bag!
Bio-Nite is a bio-solid filler we add to every bag of Starter 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:
So, for sure, you can apply Starter Fertilizer when you seed or sod, but it’s also great for anyone just looking for “all the things”. If you have a soil test that shows that you are low on the 3 big macros, (Nitrogen, Phosphorus, and Potassium), this is an excellent choice.

Starter Fertilizer 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.


An 18 lb bag covers 6,000 sq ft

A 45 lb bag covers 15,000 sq ft

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 Information:

Shipping Costs

Included for most states within the U.S.

NO P.O. Boxes

$9.95 for CA, WA, ID, and OR

State Restrictions

Alaska (AK), and Hawaii (HI)


Yes, free stickers with every order

Typical Delivery Time

4 - 7 business days

Product Type



All sales are final, with no cancellations, returns, or exchanges.