Question
QUESTION: I had a tree removed from the corner of our property due to damage from snow last year. It was quite old and probably unsound, roots were extensive and we have others (I am aware of the local bird population and this is an issue in this community). Since then I have had no luck whatsoever putting any grass here. There is more sun than prior, but the area where there is bare soil will not accept any kind of grass. I expect you will tell me to have a soil test done.  If the soil was not going to support grass, how could it have supported a tree all these years? (I am guessing this tree was at least 100 years old, an old oak.)

ANSWER: A soil test wouldn't hurt, but it won't solve your problem.  A tree that was not completely removed -- underground roots and all -- is a gourmet meal for Fungi.

Fungi are Saprophytes that are always a part of the decay of wood.  The stump and roots can decompose underground for decades.

Yes, DECADES!

Here's why:

Cellulose and Wood are some of the toughest tissues going.  Cellulose is a complex carbohydrate that gives form and structure to plants.  It undergoes decay by special bacteria that make the enzymes needed to digest those long, complicated, tough chains of Glucose molecules.  You need serious microbes to break down Cellulose.

Wood is even worse.

Wood and bark are made of Lignin.  Although Lignin SEEMS like Cellulose, they are both tough and fibrous.  Lignin will decay ONLY when here are lots of special FUNGI to do the hard work.  Unlike Cellulose, Lignin is not made of Glucose molecules.  This is Alcohol chains, glued together with Crazy Glue, welded with steel, impervious to Enzymes. It takes a real tough Fungus to break down Lignin.

Do you see where we're going with this?

Now, maybe you can get someone to grind and remove that century-old stump and its massive roots.  Because if you don't, those microbes will be working, overtime, over time - a LOT of time, like, DECADES of time.  Don't even think about sodding this section of your property.  It will look nice for a few months and then it will slowly, steadily degrade into a big ugly brown dead mess.

Now, if you can somehow accelerate this process, it can still take YEARS to finish.  Lignin is very, very tough, and Fungi are very, very patient.

Fungi do something else.  They make your soil increasingly acidic.  As they digest that Lignin, they produce organic acids to break it down.  When that happens, soil pH drops and it stays down there.

Nothing else will grow there, except perhaps an occasional mushroom.  They like to stick close to home.

It is not proven, but worth trying: After the grinding service finishes its work, douse that section with Table Sugar and Nitrogen.

Yes, I never recommend Table Sugar, but this is an exception.  Fungi have the enzymes to digest it, and it will rev up their engines.  Nitrogen will replace the N that is lost as Bacteria and their Fungi friends consume whatever is left of those woodchunks.  And keep the area moist.  Not soaking wet, just moist and damp.  Fungi need Oxygen to survive.  And they all need H2O.  Play your cards right and you'll speed the whole thing up.  This only works during warm weather; in late fall, the whole process shuts down, so don't waste time or money applying anything toward the end of the Summer.

Hope you've got a new Tree ready for any birds that used to live there.  Good luck.  Any questions on this, let me know.

---------- FOLLOW-UP ----------

QUESTION: Let me see if I understand this, you are saying there is nothing that can be done except to (maybe) speed up the decay of the tree remnants? I remove this tree with the expectation it would be replaced. If I had known this would be the result, I would have left it there.

Answer
Or you can try going in there and having the old roots and any leftover tree stump taken out with heavy duty equipment.  It's doable.  Not with a garden hoe and shovel, but with the right equipment, it's doable.  Only then would you be able to plant that new sapling.  You'll know if you missed anything -- mushrooms will pop up over the area where the wood is rotting deep underneath the soil surface.  Yes, it's a pain in the neck.  Yes, it's necessary.