My soil drains well, has supported a strong garden over the last 4 years and receives sunshine from all directions. But it is not characterized by a presence of sand or gravel type as I read is good to have for growing grapes. I'd like to begin growing grapes and am doing my research on everything. Do I need to add any of these materials ( sand, gravel etc...)to the soil to enhance it's support to growing grapes
Your answer is no you don't need to add gravel, sand, or rock. Grapes do well in poor soil, if anything I would add organic material like compost.
We also recommend getting a soil test done and amendments added before planting.