We're having cool cloudy weather this evening so I went ahead and sprayed. Decided to use the Bayer hose end bottle and go with a lower rate until someone tells me it's safe to do otherwise. Had a heck of a hard time fitting 4 ounces of ferrous sulfate in there, but I was able to dissolve that in about 28 ounces of water. Only had room for about 1 ounce of ammonium sulfate dissolved in ~4 ounces of water. In retrospect, I should have used RO/DI water to dissolve.

Sprayed about 10 times faster with the hose end than with the backpack sprayer, we'll see what happens. Seems like coverage was good.It could be all in my mind but I thought I could see it get darker right behind me as I sprayed :-)

Would still like to know about the higher rate in the summer and the correct mixing procedure for the backpack sprayer.

Oh--iron also works better if you add a little soap to the mix, about 1 oz per gallon (or 1/4 tsp per gallon if you happen to have sodium laureth sulfate or sodium lauryl sulfate on hand*).

The soap will help the iron stick and disperse evenly across the leaf, increasing absorption.

* Doesn't everybody?

Thank you very much for your help. Results were fantastic. My lawn was starting to blend in with the neighbors on color and I just can't have that :-). Last night my lawn was close in color to theirs, this is what it looks like today. Who needs nitrogen in the summer?

Does this mix benefit the plant in any significant way? Is is worth spraying it in the garden with the Epsom salts?

Other than the obvious--increasing chlorophyll, which increases photosynthesis, which increases the amount of energy the plant has? Not really. It's critical in the sense that no iron, no chlorophyll, no photosynthesis, but other than that, if the plant isn't chlorotic, it doesn't have a problem.

You can use iron in your gardens if you like. It'll darken the green hues there as well (and enhance some flower colors directly, not just by contrast). But mind spraying too much in terms of the Epsom salt in the garden. Too much Mg isn't a good thing.

About how long does one of these applications last? Would it actually be possible to cut out applying any fertilizer containing nitrogen accept for the occasional milorganite feeding?

Think of it as coloring hair. It lasts until the treated part gets mowed off as the grass grows. I don't think it would be worth doing it in the spring or fall because the grass grows so quickly it would last only a few days, but works great for summer and late fall when growth slows/stops. During the fast growing periods iron in the soil is the way to go.

The grass still needs nitrogen, just not in the summer when it can cause fungal issues.

Thanks j4c11. That comparison does make perfect sense.

It seems that at least for Bermuda, using a high nitrogen fertilizer in July-August is the norm (i.e. 46-0-0). Should I rethink doing that and go with iron supplementation instead? This question could be for anyone really.

No, what I said above applies to cool season grasses only like fescue and bluegrass. Bermuda is totally different and almost opposite being a warm season grass.

I'll defer to those more familiar with warm season grasses in regards to iron applications during the summer for bermuda.

The iron will certainly green it up. Nitrogen is important on Bermuda especially right now, but I use half rate because a pound per month makes for too Dang much mowing. I mowed then dropped .25 lbs per thousand yesterday & I can tell I'll have to mow again Thursday. It's so hot & wet down here this year the Bermuda (and nutsedge) are going nuts

Also, a lot of the newer synthetic fertilizer out there have an iron dose included--I know the nitro-phos brand has a few like that & if it's easier to find Scott's brand, I was impressed with their greenmax product the one time I used it.

You can always use Primo Maxx or its generic equivalent to cut down on the mowing for Bermuda. It also makes the turf denser and darker.

Thanks guys and especially j4c11 for letting me borrow your thread to ask some questions.