I just read your article about killing grass. I am doing that around three mature red maples. I plan to grow a shade graden under it next year. My questions are: is the vinegar safe around the trees? Does the vinegar stay in the soil so long that I will not b able to grow my new plants next spring? Thanks!!
Vinegar will get washed out of the soil by rain/snow melt so if your area has very low precipitation, it will move more slowly. I don't think this will be an issue, however. What concerns me more is the idea of planting beneath maples which are notorious shallow-rooted. That means you will be cutting through roots to plant, always a bad idea from the tree's perspective. And the roots will grow back meaning your plants will be competing with tree roots for moisture and nutrients. Guess who is likely to win that battle! Putting a layer of soil on top of tree roots is also not good for the tree and roots will migrate there anyway. One compromise is to use planters instead of planting into the ground or decorate the area with garden statuary, bird baths, etc. If you are just dying to give it a try, sow seed instead of putting in plants. The plant will have to deal with roots from the start and may be able to adapt much better than a nursery-grown plant.