You may have heard of “companion planting.” It’s the idea that certain plants like to be planted with other plants. There’s also a school of thought that says that some plants should never be planted with other plants. Part of that has to do with alleopathy, or the idea that parts of a plant can be “toxic” to other plants.
The black walnut tree is the most well known as the “plant” under which nothing else will grow but there are plenty of other trees, shrubs, annuals and perennials that exhibit some degree of alleopathy. Anyone who has had a bird feeder knows that too many accumulating sunflower seed shells will stunt the plants nearby (yet another reason not to let those shells accumulate!) For kicks, try “googling” alleopathic plants. The list will amaze you.
But scientific research into the way plants communicate took a big leap this month with the idea that plants communicate through the beneficial fungi on their roots (otherwise known as mycorrhizal mycelia). Remember how I’ve talked in the past about “the white stuff” on the roots of your container plants? That’s some of the fungi that you can actually see.
Why do you care–or why should you? A bunch of reasons. The first most important one (says the organic gardener) is because you should stop pouring chemicals into the soil. And by chemicals, I mean anything that can harm these fungi-and that includes inorganic fertilizers like those 10-10-10 or 10-30-10 formulations that you sprinkle on in granular form or spray on from a hose-end sprayer.
Why? Because they are salt-based. You are bathing your garden in salt water when you are spraying them from that handy-dandy hose end sprayer or mixing that stuff in and letting nature water it in for 6 or 9 months so you don’t have to think about it again. It may seem easy but you’re literally killing off all the good life in the soil.
So once you kill off all the good stuff (that’s invisible to the naked eye) your plants can’t communicate. And then when you get aphids, you need to go get another chemical control to kill them (when in most cases you can knock them off with a hose, allow lady bugs to eat the larva–or, if you hadn’t used chemical fertilizers to start with, you might not have gotten the aphids to begin with!)
When I get aphids, if I get aphids, in most cases, I do nothing and nature takes care of it for me. That’s another thing gardeners have to learn: bugs have life cycles. In early spring, when aphids are present, it is usually because the weather is cool and their predators aren’t flying yet. If you have patience nature will usually take care of itself. If not, a good strong spray from the hose will knock the aphids to the ground. Once there, they can’t climb all the way back to the tops of the plants, to the tender young foliage where they usually feast.
Another way to deal with the aphids is to plant a “sacrifice” plant. This is a plant that you know will attract aphids. Nasturtiums are a great one for this. This will trigger the communication among the other plants so that they will strengthen themselves. And when the nasturtiums get too aphid infested, they can be removed. Just don’t compost these because because you don’t want insects or their eggs in the compost pile.
Allowing nature to take care of things really does work–if you haven’t disrupted the balance. And if you have, by using chemicals in the past, it’s okay. Just start helping nature out with some compost. You’ll be surprised how quickly things recover!