How often should I put iron on my lawn

[The instructor]

In the professional turf. Industry iron is applied every 4- 6 weeks how often do you think a household lawn needs it?

[Moe DeLoughan]

It depends upon your soil. Iron tends to be fairly plentiful in most soils, but its availability to plants is dependent mainly upon soil pH, and to a lesser degree on the soil temperature and degree of root development. Before adding a soil amendment, it is always recommended to have a soil sample tested to determine what, if anything, you need to add.

Soils with a higher pH tend to tie up more iron in the soil, so supplementing with iron can be useful. If your soil isn't in the alkaline range, adding iron may make little to no difference to the lawn. In the long run, you'd see better results by lowering the soil pH.

Adding an iron supplement to an higher-pH soil through a top-dressing treatment, such as an iron-supplemented fertilizer, works only for a few weeks because the added iron will quickly be tied up in the soil. Thus, if soil conditions require it, it may need to be regularly applied through the growing season. However, as the soil warms and bacterial activity and root growth increases, the amount of iron uptake in plants increases. For that reason, a home owner with an alkaline soil may be satisfied with limiting iron supplementation to the spring season.

Tl;dr: don't assume you need to add iron until you have had your soil tested and have determined its pH.

[mike]

I had the same question, but for a different reason. I have a lot of moss. Iron gets rid of it. But I expect too much harms the grass??? How much is too much?

[Moe DeLoughan]

A better (longer-term) solution to your moss problem is to improve soil drainage by reducing compaction. Core aeration helps. You'll hear talk about applying gypsum to loosen soils; realistically, that only works when applied (and mixed into) the soil at a heavy rate. Top-dressing a lawn with gypsum won't cut it.

As for iron applications and potential harm to the lawn, most types of iron supplements won't have a harmful effect, with the possible exception of ammonium sulphate. That's a nitrate fertilizer that will also lower soil pH; over-apply any nitrogen fertilizer and you risk burning the lawn.

Remember, iron is the fourth most common element on earth; so it's almost never an issue of there being insufficient iron in the soil. It's that other circumstances - usually soil pH - limit the amount of that iron that plants can take up.

[The instructor]

Yeah too much will weaken and thin out the grass. Every 4-6 weeks was for high intens sports turf on a sandy rootzone which is prone to losing nutrients. While I agree with the answer given, it is always a good starting point to know ur soil PH, I don't know of many people who would do it to determine iron use, most people like yourself only apply it to. control Moss. If you are applying Iron Sulphate then 15g per meter squared is adequare to control a minor Miss problem. If you have lots of Mossi then you can apply iron to weaken it but it will not get rid of it. Physical removal through scarifying will have to be done..