For as long as I can remember I’ve believed that marigolds were the best companion plant for everything. Despite the naysayers touting time and time again that it was all conjecture, I stood by the research I could find that proved otherwise.
If you listened to last week’s Focal Point Friday episode you understand the position I’ve found myself in after all these years of companion planting marigolds in and amongst all of my garden plants. To my way of thinking, as long as there wasn’t a proven detriment to the paring then even if the marigolds weren’t preventing the pests in my garden, they would at least be attracting the beneficial insects that either were good pollinators or that actually preyed on the insects I didn’t want hanging around. And many marigolds have a strong scent and I hoped this would also serve to confuse those pests that plague my crops.
Do I still believe all these things? Yes. I will go to my grave defending marigolds as good companion plants because I have the science-backed research to show those benefits. I, as always, will link to boatloads of research in the show notes so you, too, can nerd out about some plant science. But, have I had to take a step back and do a little more research about my beloved companion before I continue to make recommendations to people in their gardens? You betcha. Because science is always evolving and so are we as gardeners and one of my favorite mantras is we don’t know what we don’t know. And sometimes we just gotta admit when we’re wrong.
Which companion plants affect the performance of green peach aphid on host plants? Testing of 12 candidate plants under laboratory conditions - Ben Issa - 2016 - Entomologia Experimentalis et Applicata - Wiley Online Library
Incorporating lemon grass (Cymbopogon citratus L.) and marigold (Tagetes erecta L.) as non-host barrier plants to reduce impact of flea beetle (Chaetocnema confinis C.) in cabbage (Brassica oleracea var. capitata L.) (actajournal.com)