A lot of us are familiar with black walnut trees and its interaction with the plants around it but allelopathy is not confined to just black walnut trees. While I have been aware of their effect on the area below the feeder, I attributed the lack of variety of plants more to the abundance of animals foraging for dropped seeds as opposed to the seeds themselves. Not the case….It appears that black-oil sunflower seeds inhibit the growth of many plants in areas below bird feeders. The seeds contain a toxin that is allelopathic to certain plants. Unaffected by the toxins are daylilies…Guess which plant I grow below the feeder? Daylilies and sunflower hulls ( photo / image / picture from Jerry Sullivan's Garden ) Along with black walnut trees, asters, goldenrod, broccoli, forsythia, junipers, perennial rye, sugar maple, rice and many other plants exhibit some form of allelopathy. For those of us that curse the lawn menace, crabgrass(Digitaria), the properties of mesotrione, the chemical analogous to Leptyospermone, a component in lemon bottlebrush (Callistemon citrons) inhibits its springtime germination. The effects of allelopathic plants are a consideration for some gardens as well as the placement of feeders. The learning never ends… Jerry
Interesting Jerry, I always assumed (you know what that gets you.) that the hulls just matted thick enough to inhibit the germination of seeds.
Good post, Jerry. Those hulls would work great mixed with woodchips on one's paths. I would love to have a walnut tree in the corner of my lottie, but they are prohibited on the complex precisely because of their allelopathic qualities.
For those of you with an eye for words you may recall a post about the area around plant roots called the Rhizosphere. If you missed it here it is again. http://www.gardenstew.com/about31374.html So when I happened across garlic mustard(Alliaria petiolata) when looking for information about allelopathy, the word Mycorrhizal fungi sort of jumped out, I could now relate to the generated lack of the symbiotic interaction. Garlic mustard is an invasive plant species found in the temperate forests of North America. Its success may be partly due to its excretion of an unidentified allelochemical that interferes with mutualisms between native tree roots and their mycorrhizal fungi. While reading about plants we often run into unknown words. Run into them enough times and they begin to stick. Jerry
