Cindi, I posted what's below in the original thread, but asked that the discussion be brought here. This was in reply to DennisB's post:
That really is a great article to read, not just for gardeners. I guess it could also be applied in a very general sense to the "toxins" sent out by some plants to repel animals and other insects. Gardeners have planted these types of plants around the edges of their gardens for a long time to keep certain animals and bugs out. Huum...I wonder if they could be used around the edges of the apiary?
Ok, I really did open up a can of worms, didn't i?
There's a difference between repelling and allelopathy. Plants can posess allelopathic qualities, not animals. A monarch butterfly eats milkweed, which is highly toxic, thereby acquiring the toxicity of the plant so no animal want to eat the butterfly - that's not allelopathic behavior. Planting marigolds around a garden will repel, but not poison, certain insects that might want to do your garden harm. Black walnut trees exude a toxin from their roots, called jugulone
, that has allelopathic qualities and will kill many plants living within its dripline. Some plants have a tolerance for it
, however, and will grow just fine.