It’s disappointing to put together a pot of several seemingly matched plants–even of the same species, only to have most of the plants dwarfed and out-competed by one of their pot-mates. Sometimes you want to throw your hands up and quote Rodney King, “I just want to say, you know, can we all get along? …I mean, we’re all stuck here for a while. Let’s try to work it out!”

A study published last year by McMaster University biologist Susan Dudley sheds some light on the phenomenon. She found that sibling plants of the same species coexist nicely when grown in the same pot, being generally considerate of each other as they produced their root systems. But in contrast, plants of the same species that were “strangers” to each other produced highly competitive root systems that didn’t show the same level of cooperation.

“Though they lack cognition and memory, the study shows plants are capable of complex social behaviours such as altruism towards relatives,” says Dudley in the McMaster Daily News. “Like humans, the most interesting behaviours occur beneath the surface.”

According to the report, the study was done with one species, “sea rocket (Cakile edentula), a member of the mustard family native to beaches throughout North America, including the Great Lakes,” so its effects might be different with other species.

But the next time you assemble a container planting it might be interesting to see if cuttings of one plant or seedlings from the same clones develop a more cooperative living arrangement than wildly different clones taken from the entire vegetable diaspora of the same species.

Image from:USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. Vol. 2: 196.