Using Shingles To Warm Ground Around Tomatoes – But Are They Toxic To Soil?

Q: I heard you talking about using shingles to warm up the ground around your tomatoes. Shingles sound like the perfect weed barrier: won’t blow away, won’t deteriorate, heat up the soil, etc. But are there toxic chemicals in them that would leach into soil?

A: I had no problems doing it last year and my tomatoes looked healthy. People do wonder about the toxicity of shingles but they forget that most rain barrels collect water that runs across their home’s shingles and they then use that water on their vegetables. I don’t think there’s anything particularly toxic in shingles used to achieve early soil warming in the garden.