Each year I like to try some kind of experiment in the garden. I truly believe that the best way to become a better gardener is to try new things. This year I will be putting one of the most commonly talked about organic pest control methods to the test. I am going to try a companion planting of tomatoes and marigolds to keep the stink bugs away.
If you believe everything you read, then you no doubt believe that marigolds are miracle plants. It is truly amazing to me how many articles/posts there are on the internet making incredible claims about their bug fighting abilities. One of the more recent things I read swears that all you have to do is plant a marigold in each corner of your garden and all of your bug problems are solved. While there may be some truth to the marigold’s bug fighting abilities, I really don’t believe they are going to very successful at riding my tomatoes of their stink bugs.
Now don’t get me wrong. I really want my experiment to work. In fact, I have gone out of my way to give the marigolds as much of a chance as possible. Instead of trying to plant four plants in the corners of my garden, I am going to completely surround the tomatoes in marigolds. For this experiment, I grew about 100 marigold plants from seed in my new back porch seed starting rack. Once the little plants got up to about four inches tall I used them to line the triangular beds of my potager. I planted the starts six inches in from edge and spaced them at six inches. It took about 20 plants to line each bed.
Once the flowers were in, I planted the tomatoes. For this experiment I am using romas. Romas grow on nice, neat determinate bushes. My thought is, those nice, compact determinate bushes will give all of those pesky bugs fewer places to hide. I am also hoping that their relatively open form will allow whatever magic bug fighting qualities the marigolds possess to waft freely deep into the bush where the bugs are hiding.
I apologize a little about my attitude here. I really, really, really want the marigolds to run all of the bugs off. However, I am very skeptical. Even though I am doubtful of the marigold’s bug fighting abilities, I do truly expect they will keep any nematode issues at bay. It is a proven, scientific fact that marigold roots secrete alpha-terthienyl. This compound has insecticidal, nematodial and anti-viral properties. It also stops nematode eggs from hatching.
My last big garden experiment was growing potatoes in a box. That one was a complete failure. I had very high hopes for that one when the experiment started. For this one, my expectations are a bit lower. I expect to have almost aero nematode problems but I really don’t expect the marigolds to be very successful at keeping the bugs away. Only time will tell. Check back at the end of the season to see how it goes.