Plants crowd out unrelated neighbors

…The next time you venture into your garden armed with plants, consider who you place next to whom. It turns out that the docile garden plant isn’t as passive as widely assumed, at least not with strangers. Researchers at McMaster University have found that plants get fiercely competitive when forced to share their pot with strangers of the same species, but they’re accommodating when potted with their siblings.

Plants recognize their siblings, biologists discover

More information:
Plants know their relatives and like them
Once considered outlandish, the idea that plants help their relatives is taking root