Question
I have a 1 square foot patch of grass that every year dries up and turns brown, despite the fact that the rest of the lawn is green. Making it weirder, in the winter, if there's a blanket of snow on the ground, this same exact spot always melts first. I'm concerned that there might be either some chemicals in the ground, or possibly something like radon causing both the lawn death and snow melt. I've been noticing this pattern for 3 yrs now. Do you have any thoughts about what might be causing this?

Answer
I'm no Radon expert, my friend, so I asked a fellow genius named Mark Dominus for his comment on your Radon concerns.  If I had your zipcode, or your general region, we could lok on a geological map and actually SEE if Radon is an issue in your local construction.  Here on Long Island, it is not.  Upstate NY, most definitely.

But this question goes further than that.  And so let me tell you how Mr Dominus opines on your Radon fears and I quote:

'I would be extremely surprised to learn that this (snow melting/grass killing) was caused by Radon.  Radon is a gas, produced in tiny quantities by the decay of naturally occurring radioactive elements in the Soil.  It is heavier than Air, and so sometimes collects in people's basements.  I can't think of any way that it could possibly affect a small patch of Grass.'

So let's look at that paragraph one more time, especially that part that should help you sleep better at night: I CAN'T THINK OF ANY WAY THAT IT COULD POSSIBLY AFFECT A SMALL PATCH OF GRASS.  Translation: This is not caused by Radon.

He continues: 'Maybe the Sun happens to reflect off his windows onto that patch of Grass in the early morning, and that's what kills the Grass and melts the snow.  Maybe the neighbor kid is in a habit of standing there when he plays catch.  Maybe the early snow melt is caused by the poor Grass cover in that spot.  It could be anything.  Who knows?  But I can think of a lot of explanations that seem more plausible than Radon.  I like your buried stump theory too.'

Ah, yes, the Buried Stump Theory.

The most obvious answer of all.

And the longest.

To understand this problem, let's first take a look at the Iowa/Kentucky State/USDA essay about Wood Mulch, 'Using Mulches in Managed Landscapes':

http://www.extension.iastate.edu/Publications/SUL12.pdf

The pro's there point out, 'Mulch derived from the bark of mature softwood trees, including Pine and Cypress, is very resistant to decay.  Bark from young softwood Trees decomposes more quickly because it does not contain the high levels of Lignin, Waxes and Tannins characteristic of bark from mature Trees.  Hardwood bark, because of its high cellulose content, also decomposes rapidly.'  (By 'rapidly', by the way, the authors do not mean days, or weeks, but seasons -- as in years of seasons.  But we'll get to that.)

Iowa Experts make another point in the same Mulch essay: 'Organic mulches can dramatically impact soil microbial activity and nutrient availability.  Mulches with a high Carbon-to-Nitrogen (C:N) ratio, such as hardwood bark, ground wood pallets, straw and sawdust, can induce Nitrogen deficiency in plants by stimulating microbial growth, which depletes underlying Soils of available Nitrogen.'

Stephen, do you have any idea how often I get questions from people with mysterious, recurring Brown circles in their Grass, year after year?  They put down Sod, the Sod is beautiful for a few months, then it turns Brown again.  They replace Soil in that spot, then they re-Seed and/or re-Sod, and the same Brown spot appears, over and over.  No matter what they do, there is that patch of Brown.  Desperate, they find someone on AllExperts who can explain this bizarre and discouraging problem.  And this is the explanation.  There was once a Tree growing there.

Take a look at your house for a second.  Step back, to the property line, and imagine you could see a Tree growing where that Brown spot is that melts snow.

Would a Tree look good there?

Someone who is not into Trees might want to grow Grass there?  They might remove it?  Grind the stump?  Patch over it?   Until finally the house was no longer theirs, and the stump is now only a memory.  Maybe a neighbor of yours, someone who has lived there much longer, remembers that Tree.  Just to confirm this Stump Theory.

Because no matter how you grind, there decaying wood will be there unless you take it out.  And that can be pretty difficult if you're talking about a mature old Tree with roots going this way and that way and down and everywhere.  Pretty much impossible, in fact, to remove.

So let's see how they deal with Wood Mulch in Iowa:

'Mulches such as composted yard waste and Wood or bark blended with composted Sewage Slude (aka Milorganite, for instance) can increase Soil fertility and plant growth because their low C:N ratio resembles high quality forest litter.'

Let's say you have microbes (Fungi, Bacteria) rotting that stump underground.  It makes sense that if you have a LOT of microbes, the stump will rot faster.  Things like Weedkiller and Chemical Fertilizers (which are Salts and hence very bad for microbes) result in FEWER microbes.  Organic care results in MORE microbes.  Therefore, you'll get FASTEST decomposition if you have MORE microbes and FEW to ZERO caustic microbe-damaging Chemicals.

But...

Since the Microbes are really building up a sweat over this Tree stump, they are also drinking TONS of Nitrogen to keep up all that work.  Which explains why, in a study of Wood and Compost Mulches mentioned in the Iowa essay above, the Wood Mulch 'introduced a Nitrogen deficiency'.  When the researchers added Nitrogen fertilizer, however, the authors note that they 'substantially increased the growth of plants mulched with ground Wood...'

As far as the Snow melting, you probably understand that the Sun heats the darker Trees more than it heats the white Snow; the Trees radiate infrared energy and the Snow around the Tree absorbs the heat. And you see Snow melting around the Tree.  Spring blooming Bulbs first come up under Trees and near sidewalks.  But this only applies to TREES that are still growing above the ground.  Not to stumps.

In the Summer, the temperature underground would be higher than surrounding areas because those busy microbes generate a lot of heat.  But it is my understanding that Wood-rotting microbes cease activity when it gets into the 40s or 30s.  Depending on where you live, if the stump is deep underground, it will still be generating heat when it snows, melting snow in that one frustrating spot on the Lawn.

Bottom line:  Mulch this Brown patch and its surrounding area with an organic fertilizer that is packed with Nitrogen.  Top dress often.  The constant stream of N will set microbes at peak performance, with a little extra left over for the Grass. Note this is going to take some work -- you have to find the balance.  But it will work.  Simply removing the Soil or patching the area with Sod will not work.  Or you could just place a Bird Bath in the same spot.  Nothing wrong with that.