I've always liked the tall Yarrow called, I think,' Gold Plate'. I grew some from seed and put a group of them in the hillside garden and I've liked them there. They provide a bit of muscle in what could be a flabby setting of Phlox, Shasta Daisies, blue Veronica and such.(There are also a lot of Coneflowers in that border, but they are over to the one end.) The Yarrow's fairly sharp mustard yellow is a bit jarring, but there is such as thing as too much good taste.
A plant of wild Yarrow, Achillea millefolium, wasted no time in joining its cousin. Since it bloomed a very clear crisp white I left it. It's not visible from the front of the border, but when you go around the back, up the rock steps, it's there and fits in well with it's slightly shorter stature, dusty green foliage, and rather open flower clusters. A Yarrow is of course one of the Compositae, so what looks like a flower is really a group of small flowers, called florets, each of which is itself composed of a group of even smaller flowers. Confused? Sorry. The thing we call the Flower, in a Yarrow, is a corymb, and is composed of multiple Heads, each of which is composed of two types of flowers - Ray flowers, and disc flowers. Each one is actually a tiny Daisy. There is no end to the designs, combinations of designs and groupings of combinations of designs in nature.
Just as there is no end to the hanky-panky that goes on behind the scenes.
My yarrows have now produced an intermediate form. It has the shape and size of 'Gold Plate', in fact it might even be a bit taller, the greyish foliage of the Wild Yarrow, and a colour right in between the two. It is a soft but distinct yellow. When I look at the individual heads closely, I see that the disc flowers (the ones in the centres of the flower heads) are pale yellow, while the ray flowers (the 'petals') are white.
I just checked the books. Apparently, 'Gold Plate' is a variety of Achillea filipendulina. Also listed is a plant with pale yellow flowers like my seedling called A. 'Taygetea' which it describes as 'a hybrid of uncertain origin, probably between A. millefolium and A. clypeolata'. Hmmm. I don't have A. clypeolata around, as far as I know, and in any case the leaves on my plant look different from those in the book. The leaves on my plant look exactly like the leaves on 'Gold Plate' only with the colour of the A. millifolium leaves.I can't tell whether the ray flowers of the plant in the book are white like on my plant. In any case, I guess it's safe to say my plant is 'of uncertain origin'.
The Yarrows are coping well with the drought this summer, another reason to like them.
They can be cut right to the ground after they bloom (and they stay in bloom a good 3-4 weeks), or you can cut each flowering stem off at ground level. If you have only a few plants and enough time, you can cut the individual stalks, but if you have lots of plants or little time, you can just give the whole thing a bean shave with the garden shears. My kind of plant!
The pink, red and rust coloured Yarrows, by the way, are of quite different parentage, and behave very differently, at least for me. They are much shorter, need to be divided every year to keep them from running out, and do not do at all well in a drought. I keep one clump going in the Herb Garden just to be able to say I have Yarrow.