How to Green Up Your Lawn with Iron Supplement

Bag of ironite fertilizer
If you’ve ever wondered how your neighbor gets such a dark green lawn, the answer just might be iron. A favorite secret weapon of lawn care professionals and golf courses, iron supplements help to impart a lush, deep, blue-green color to lawn grasses.

Iron is particularly effective with fescue and bluegrass, helping these grasses stay deep green during the hot summer months without the increased growth (and subsequent water needs) caused by nitrogen fertilizers. Iron also helps control moss and is the active ingredient in products such as Moss Out.

Types of Iron Lawn Supplements

There are two main types of iron supplements:

    Container of liquid iron supplement

  • Synthetic Iron Fertilizer: Manufactured iron rich fertilizers, such as Ironite, are an inexpensive and fast-acting supplement. They are usually spread as granules, with foliar sprays also available that can produce results within days. The disadvantage of synthetic iron fertilizers is that they can turn your lawn gray if over applied, and if you’re not careful when spreading, they will stain your concrete driveway a rusty-orange.
  • Organic Iron Fertilizer: Organic sources of iron, such as Milorganite and greensand, are slower to break down, but the iron is naturally chelated, which makes it more readily absorbed by the plants. Organic iron sources won’t stain your concrete, and they contain other nutrients that naturally build up your soil and lawn.

How to Apply Iron Lawn Supplements

The best time to apply iron to your lawn is in the spring, when temperatures are in the 60s to 70s F. Avoid spraying or applying iron during hot weather. Follow package instructions exactly, to prevent overdosing.

Grasses don’t require a lot of iron, and it’s generally not needed unless your soil test indicates an iron deficiency. If your lawn is yellow, first make sure it’s getting enough water and regular nutrients before trying iron supplements.

Further Information


  1. Hello,
    I just caught your show this morning. I have been taking care of my lawn for several years after giving more money to lawn care people and getting no results. The lawn is usually in good shape, but I have problem areas. Last year I did put down seed in the fall and it did come grow in some of the areas. I do have some sandy mix. I would like to try the iron and the fescue. I have never seen the suggestions on any other show or page.
    Thanks Rita

  2. Iron is a good way to promote more chlorophyll, and greener grass without promoting a lot of growth. It can be applied in the summer if the grass is not dormant. I use a sugar-chelated Liquid Iron. It has a bit of nitrogen and manganese in it to help it work faster.

  3. What is the shelf life of liquid iron supplements? I have two gallon jugs that are both probably over 5 years old and wonder if they would be dangerous or ineffective to use on my lawn next Spring. HP

  4. I LIVE IN NAMPA ID IN APPLING IRON WHAT IS A GOOD SETTING ON MY SPREADER..i assume ALOW SETTING…CAN I OVER DO IT AND IF I DO WILL THE GRass be ruined ? Im getting ready to do ,my fertilizing for the spring.. thks fred

  5. The lawn care company we use just liquid fertilized my yard this past Friday. When they did it stained my fence because of the liquid iron in it. they used Primera One and now my wood fence that was only 5 weeks old is stained. I feel bad for them but need it fixed. They are offering to replace, but I am wondering if you have a suggestion to clean it. Turned gray.

  6. I’ve used IRONITE in the summer on my kentucy blue grass in the summer to green it up never had any problems…EXCEPT I also got some on the sidewalk and concrete driveway, and yes iron leaves a rust stain which literally had to wear off…

  7. For the ones that say iron stained their brick.

    When you get iron on concrete take a few steps.
    This has to be done as soon as it hits the concrete.otherwise it’s harder to get up.
    1. Sweep or blow off all the noticed grains before water hits it.

    2. If you don’t get it all,wash down the concrete with lots of water,this usually helps.
    3. Use a solution of strong simple green and water with a scrubber sponge. On any rusty spots.
    With this you won’t have any issues.

  8. I am using an older Ortho broadcast spreader to apply Ironite to my lawn. The package does not mention Ortho spreaders so that I know what setting to use. I’ve been online searching for the answer for over two hours now. I hate to buy a new spreader just so I know the setting. Can you help me PLEASE?!? Thank you?

  9. I bought a 40# bag today of House Professional Iron Works to spread on my St. Augustine grass, but my turf builder 3000 spreader is not listed. The bag says it is good for 2500 sq. ft. and made for the Waco, Texas area. Do you have any idea what the seating might be? I cannot find a number on the bag to call.
    Thank You and God Bless

  10. I have a new yard of St Augustine that was put down in November. Early spring I used Weed & Feed, late May it was fertilized, the yard never did green up, about three week ago I used the Ironite and it has yet to green up. I have used Ironite before started to see results in a matter of days What else can I do to get a deep green yard??

  11. I’ve used ironite several times and it works wonderful accept for the issue of rust on the sidewalk or driveway and I will look at the other alternatives mentioned to use. My gardener mentioned after using that the grass was growing fuller and stronger. I’ve currently started using Epsom salts as the magnesium helps with the production of chlorophyll and has helped to green up my lawn. I will be trying to use both these to see how well they work together.

  12. I live in Central Florida and plan to fertilize my St. Augustine with Milorganite. Can I also use lime to green the grass, and if so, how long after fertilizing can I use the lime?

    Thank you,


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