Q: Several of my plants are dying from root rot. A nursery employee said to mix hydrogen peroxide with water and put it in the ground at the base of the plants. He said that by re-introducing oxygen into the soil, the problem would right itself.
A: Adding hydrogen peroxide to the soil is a bad idea. While the peroxide will produce a bit of temporary oxygen, it will destroy organic matter in the soil as it bubbles. If the plants are truly dying from root rot you need to correct your watering schedule (once per week) and make sure to add soil conditioner before planting, which will permanently increase drainage and combat root rot.