What best practices should I suggest to Annual Plant Sale donors?
I am working on an Annual Plant Sale and am seeking guidance about best practices to share with our plant donors — some of whom will be digging from their gardens — to reduce the likelihood of transferring crazy worms, invasive moths, or other general hangers-on. We always require that plants be potted in new, sterile soil, but should people also rinse the roots? Wash their pots in bleach or vinegar? Wait for a time to transplant to reduce winter moth? We welcome your guidance!
Tori Lee Jackson, Extension Professor of Agriculture and Natural Resources, University of Maine Cooperative Extension Androscoggin and Sagadahoc Counties
Because it can be relatively easy to unwittingly spread invasive insects or weeds (via seed), we have in the past recommended that no plants be dug and repotted in areas where species like Winter Moth are known to be present. In 2018, several plant sales in Maine were canceled for this reason. The next best option is to always use sterilized pots and media, sterilized tools such as trowels and shovels, and then using rooted cuttings rather than divisions when possible. Root washing could be effective, but it requires a lot more work and it’s effectiveness depends on how thoroughly each gardener/donor rinsed each plants’ roots. I recognize this is a big departure from the way things were just a few years ago, but if reducing the spread of invasive species is a priority (and I’m glad it is!), this is what I’d recommend.