Question
I have a situation similar to that posted by Anne on June 5, 2006 with the same Subject line, and answered by Dr. Dean Marston.

I had two trees removed and their stumps ground down: an old cherry tree in the front yard, and a willow tree in the back yard.

The contractor stripped off the old grass and vegetation, brought in loam, and graded the yards. He then sodded the front and seeded the back.

The sodded lawn looked beautiful for about 5 - 6 weeks but now the area where the stump was has turned yellow and is starting to die. The grass in the seeded back yard sprouted and appeared to be doing well, however, the seedlings where the stump was have died and the area is bare.

No herbicide was used on the tree stumps.

Anne mentioned that she had tried baking soda and water on her area, however, I am unfamiliar with that treatment.

Would you have any suggestions? Thank you.

Answer
Hi Hank,
When a stump is ground out, the sawdust that remains does two things.  As it decomposes it robs nitrogen from the soil, basically starving the surrounding plants and it releases tannic acid which plummets the pH.  When the pH drops below 5, many nutrients become locked up in compounds that are not usable to the plant.  The lower it goes, the more nutrients become unavailable.
Baking soda raises the pH but there are cheaper ways to do that.  Apply lime immediately. Normally I'd use agricultural lime on turf, but it works slowly and since your grass is dying, we need quicker results. I'd use weekly light applications of hydrated lime.  This raises the pH quickly so make sure you follow label directions.
Also, spray feed your grass with a water soluble high nitrogen fertilizer.  Nitrogen may not be available in the soil unil we correct the pH problem but it can be absorbed through the leaves and it is very hungry!
Check your pH frequently and continue liming and fertilizing until the pH stabilizes around 6.5.
Keep me posted on your results. Jim