landscaper #1 said he would pull the ivy by hand and hand tools, haul in fresh topsoil and mix it with the existing material, re-grade a bit and seed or sod.

Landscaper #2 said he would use a sod cutter on the ivy, dig out and remove the soil that contains the wood grindings and haul it to the dump, then add fresh top soil.

Another opinion to wait a year before planting grass, to allow the acidity in the soil to neutralize, then just regrade and sod or seed.

Any other ideas or thoughts?

Number 2 should also regrade when he brings in new topsoil. I would not be quick to jump onto the idea of new topsoil over the entire area. Drainage is the ONLY consideration as to whether new topsoil should be brought in. If you need soil to bring low spots up to grade, then do that. Sometimes the landscaper may want to move soil around to get the best drainage. Let him. He's the expert on that.

If he does not bring in new topsoil, then you will be interested in improving the old soil. That is easy with the new understanding of how soil biology works. When I say new, I mean since the 1990s. This new approach to soil improvement is in two steps. 1) provide beneficial microbes with a LIGHT dusting of compost. The total amount you will need is 1 cubic yard per 1,000 square feet. 2) feed the soil microbes with real food. The easiest thing to feed them is animal feed from your local feed store. This year with the high price of corn I have switched over to alfalfa pellets (rabbit food). The application rate is 10-20 pounds per 1,000 square feet. It you mention this to your landscaper he'll think you're nuts because this is such a different approach.

The old approach would be to smother the soil with compost (amazingly expensive) or to rototill several cubic yards per 1,000 into the soil. Without getting into the details, this approach will delay your lawn's establishment and growth. Again it has to do with the microbes in the soil and how they feed. Mother Nature has been applying Her microbes and food at the surface, every autumn, for billions of years and that is the way that works best.

What happens with this new approach is the soil microbes decompose (eat) the alfalfa and convert it into plant food for the grass. The microbes digest the protein, carbohydrates, vitamins, minerals, and enzymes to create the food that Mother Nature has been making. All you have to do is add the food and water. In the process the soil becomes natural and healthy.

Okay enough theory. The best time to seed a lawn is in the fall. If you do it during the heat of summer, the grass will never get started. The tender roots of the new plants will dehydrate and die. This is true with spring seeded lawns, too. Seeding must be done in the fall. On the other hand, you can lay sod any time of year.

What if I regrade, followed by 3-inches of topsoil over it (instead of tilling it in) then plant grass? The grass would be growing mostly in fresh soil?

Another possible option your information has sparked: I could move all the soil/wood mixture into a mound (say about 15 feet diameter) over where the big tree was, see if I could find a tree or large shrub that could thrive in acidic soil and plant it in the middle, and perhaps some smaller acid-loving plants, flowers and mulch around it. Then plant grass outside that 15-foot circle for the rest of the yard. Any issues with this approach?

your "new approach" sounds interesting and I do wonder what the landscapers would say. Both landscapers have been in the business for 20-30 years. On the other hand, I get the feeling they are also in a hurry to complete the job the way they are used to doing it and possibly according to company policy. If I can do it tactfully, I'll bring it up and let you know. If I were to do the work myself I certainly would consider it.

I would not recommend the tree plan. As dchall mentioned the problem is not so much the acidity but rather the poor conditions where the stump was ground. All of the tree bits are going to need to decompose and to do that they require a large amount of nitrogen (which again is not prevalent underground). You can use potassium nitrAte to help speed along the process (sold as stump removers), but there are a lot of anaerobic (without oxygen) bacteria/fungus that create some nasty gases that hamper growth on top of this area. Hydrogen sulfide is one of the main culprits and will readily kill.

If you've ever cut out a hunk of wood from an old stump (>2 years) and give a sniff you'll smell the sulfer (rotten eggs) from the decomp.

I'd also agree that if you goal is to go with grass, you need to remove as much root as possible, haul in new soil, and give it a shot.

Just know that the remnants of that tree will be there for many years to come.

HTH