Walnut Tree Mulch

Q: This spring, after planting the garden, we heavily mulched with fresh shredded material the power line maintenance crew brought us. It has been a total bust. The tomato plants were dwarfed, the cukes were disfigured, and I only had a couple of eggplants. Did the mulch cause this?

A: It’s possible the mulch did the damage, especially if it contained walnut tree chips. As you probably know, walnut wood contains chemicals that injure garden plants. But even if there were no walnut chips, a thick layer of fresh mulch could contain enough raw sap to harm plant roots. This year’s garden may be a bust but the chemicals will dissipate with time and next year’s garden should be fine.