Looks like Tansy
by Barbara Morrissette
(Willits, CA)
leaves, 2 large and new one
near the top, in flower, some buds
the flowers after opening
I have a "weed" that has established itself in the rose bed. I've never had it before, so am not up on its' identification. It looks like Tansy, may be a variety of it from the drawing on Wikipedia. The leaves are a bit wider than the drawing; it has the yellow flowers, but the button is developing into a little daisy with skinny petals. It has an unpleasant odor, not repulsive. A couple of the plants have a gray color instead of green.
It has grown 5.5 feet high and is actually overtaking the roses, so I ripped some up and threw them over the fence, where I occasionally throw other things that deer will eat. They won't touch them!!! No doubt the odor has turned them off. So far the plants have dried up and no animal has eaten them.
Now, last week a deer got into the garden briefly, as I noticed a few rose branches eaten, but he/she didn't go near the place where the "tansy" is growing. That doesn't mean much, I know. Possibly it was a small deer, as they are not too knowledgeable about plants.
From the webmaster: I have a MS in Horticulture, and it looks like Tansy to me. I used to grow a lot of it and it has a strong smell. The herb is used for some medicinal applications, but it is toxic to down right posion, so you shouldn't have to worry about the deer eating it. If you want to put it in a better place, wait until it dies down this winter, dig it up, divide the crown with a knife, and then plant you new pieces wherever you want to deter the deer and rabbits. It can be pruned down if it is leggy and you want to keep it bushier.