Question
I saw a local garden expert on TV last week.  He suggested putting pelleted iron on the lawn to keep it green.  I bought a bag.  It doesn't say to put it on before a rain is due, or just after.  How about if we're having some really hot days here in VA?  Will this do more harm than good?  Thanks!

Answer
Someone please put me on television to straighten these people out.

IRON FOR YOUR LAWN!  Yikes!

Sounds great, doesn't it?  'Iron'.  Like, the stuff you get in Vitamins.  Like the stuff after the word '2 percent with' on the box of Scotts Turfbuilder WITH IRON.  Even the local garden experts are swallowing this Suburban Myth.  And believe me, it is a Myth!  A BIG Myth!

Let me tell you why.

Iron deficiency - called Chlorosis - does occur in Grass.  But it has NOTHING to do with the Soil not having enough Iron.  Because there is PLENTY of Iron in most U.S. Soil.  Did I say plenty?  There's MORE THAN ENOUGH!

So what then causes Chlorosis in Grass, if there's 'more than enough' Iron in the Soil?

Did you know that Chlorosis can be caused by the wrong pH?

For the benefit of all readers, Soil pH controls whether Turfgrass can get nutrients (like Iron) out of the Soil.  In a perfect world, Grass usually grows best in Soil with a pH of 6 to 7.  When the pH is too high, or too low, nutrients don't get into the Grass.  You see symptoms of a kind of vitamin deficiency, like Iron.

As I told someone else not too long ago who wanted to dose up his Lawn with Iron, an Iron deficiency is the first thing that happens to some Grass when it doesn't like the pH.  Although Zoysia can be sensitive about pH, it is not a problem that you would notice unless the pH was VERY high -- higher than 7.5.  At this range, the Grass becomes so starved that it turns a lovely shade of yellow Green.  Putting Iron all over it does not really fix the problem.  Of course, the people at Scotts won't tell you that.  This is a much easier way to make money.

Fixing the Soil pH is never easy.  Fixing Soil pH in established turfgrass is even harder.  And if you have a poor-Soil problem, you won't fix it at all by adjusting the Soil pH; you need to increase the organic matter in the Soil.  If Soil pH and iron are solid, but the leaves are Chloritic, you could be looking at a problem with Grass roots.

Since we're on the subject, I recommend you pick up the article on Lawn chlorosis, "Grass Yellowing: Save Your Greenbacks":

nfrec.ifas.ufl.edu/Newsletters/Archive2005/Newsletter_05_09_05.pdf#search='zoysia%20symptoms%20iron

It was posted by the North Florida Research and Education Center.

Then go out and subscribe to Rodale's Organic Gardening.

If you want to do something nice for your Lawn, get a Soil test.  And if your pelletized Iron still isn't needed, give it away to someone who does need it.  Better still, return it.  Send me the refund.  Thanks for writing.

THE LONG ISLAND GARDENER