2016 February 6

The tansies (the upright plants in the foreground with the yellow, buttonlike flowers) are duking it out with the goldenrod and the wild peas to take over large portions of our property, as can be seen in this photo from August 19, 2015.

They stand about three feet tall, and devote a lot of resources to their blossoms.

The blossoms are about a quarter of an inch across, very hard, and last for weeks if not months. They are pretty good nectar plants, the bees work them for most of the later part of the summer. For a bit of a “Where’s Waldo?” moment, try to find the ant drinking nectar in this next picture:

The common tansy, Tanacetum vulgare, is one of the many plants in the Asteraceae family, and has the typical composite blossom composed of many tightly-packed individual flowers. They are basically daisies without the ray petals.

The leaves are feathery, fern-like things that are kind of tough and have a rank odor.

The only thing I’ve seen eating them so far are the caterpillars of Painted Lady butterflies, otherwise they are largely unscathed by the local wildlife.

Anyway, Tansy is your classic non-native invasive plant. It grows fast, rapidly colonizes new areas, produces millions of seeds, spreads by rhizomes to make large patches, shades out or poisons most competing plants[1], is so foul-tasing and toxic that hardly anything wants to eat it, and as a Eurasian import it has gotten away from most of the few things that did evolve to eat it.

I have mixed feelings about the tansy. On the one hand, it is a not-terribly-attractive plant that definitely Does Not Play Well With Others. On the other hand, the bees get a lot of nectar from it. Overall, I guess I can live with it.

[1] We do have a few other plants that give it a run for its money, though. The goldenrod has similar growth habits, is resistant to the tansy toxins, and seems to be able to win out in drier parts of the yard. The wild peas can root outside of the area poisoned by the tansy roots, and their very long vines can overrun and smother the tansy with impunity. It will be interesting to see who wins out in the long run.

2 Responses
  1. Carole permalink
    February 6, 2016

    Hope you can cut the blooms of your tansy back before it produces seed.

  2. February 8, 2016

    Unfortunately, it is much too late for that. The tansy had largely taken over swatches of our property before we ever even bought the place. I’m sure the soil is well-saturated with tansy seeds by now.

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