Companion planting Gardening

Plants Help Their Relatives

20160731A.jpgSeveral studies show that plants recognize their closest relatives, that is, plants born from the same mother, and offer them preferential treatment.

In particular, when a plant grows beside a relative, it directs fewer roots in its direction and grows less quickly, giving it a chance to settle in.

The presence of an unrelated plant in the area, however, even of the same species, causes the opposite reaction: it sends out more roots in its direction to take over as much soil as possible and grows more quickly, creating denser shade, apparently in an effort to out compete its neighbor.

At this point, no one is exactly sure how plants are able to recognize their kin, but some researchers speculate that it’s due to tiny chemical signatures present in the roots that are specific to closely related plants.

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

5 comments on “Plants Help Their Relatives

  1. marianwhit

    Love seeing this…been seeing it “in the field” for a long time! Do you have references for these studies? I would dearly love to have them.

    • There are quite a few of references. Here are a few:

      Dudley SA, File AL. Kin recognition in an annual plant. Biology Letters 2007;3:435-438.

      Karban R, Shiojiri K. Self-recognition affects plant communication and defence. Ecology Letters 2009;12:502-506.

      Klemens JA. Kin recognition in plants? Biology Letters 2008;4:67-68.

      • marianwhit

        Thanks so much…I have not been back to this site in a while and did not see your answer.

  2. But…but, what if my relative is…a loser?!

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