Tuesday, July 6, 2010

yarrow is not a four letter word

Yarrow (Achillea spp.) has been coming up a lot lately in garden conversations and I wanted to set the record straight. Is it an annoying invader, or a garden-worthy native? In each case that someone described an annoying invasive yarrow, the plant in question turns out to be not our native white yarrow (A. millefolium) but rather a non-native species or cultivated variety of yarrow.

Yarrow is a native plant that can be used quite well in a variety of garden situations ranging from xeriscape prairies to conventional applications. The native yarrow is an example of a plant that you do not need to use anything but the native. Using a variety bred for showiness or color could get you in trouble (unless you enjoy endless weeding).

Our native yarrow is beautiful, durable, drought tolerant, fragrant and offers year long interest with its beautiful seed heads and adds an important architectural element in the garden if left uncut for the winter. The flowers are also great in cut flower arrangements.

We use yarrow in our own garden landscapes and encourage its use by our clients. It is easy to grow, liked by butterflies (it offers a nice landing pad- see the photo at the beginning of the post), and very versatile. Aesthetically, the native yarrow is the right color for semi-arid western Montana. Its leaves have a beautiful soft and feathery texture and have the silver-grey cast that is common to so many prairie plants. This grayish-blue color is an adaptation to the sunny and dry prairie conditions: it reflects sun.

Over the last couple of weeks people have been surprised that we planted yarrow at the neighborhood park we have been landscaping, at the Home ReSource landscaping project we designed and installed, and a client of ours, wanted to know how to control the “native” yarrow he planted. In the case of the client- the yarrow he thought was native was actually a pink flowered variety, and in other cases, it is always an escaped lawn weed that takes over, giving our native beauty a bad name.

We use yarrow in a a variety of settings in our garden- ranging from naturalistic- in our front yard prairie where there are individual plants scattered (see the white flowers in the photo below ),

and we have grouped several plants together in our backyard to create a wash of colors that compliment the purple clarkia, and fleabanes- see below.Yarrow is a common plant in garden centers and in the landscaping industry, and it represents a great example of why you need to know what you are looking for if you are shopping for native plants. Although we do have a native yarrow, most of what is sold is not native. Yellow flowers, pink flowers, and even white flowers adorn many commercially available yarrow. But most behave much differently than our own, native plant. Many non-native yarrow will turn weedy if watered, and even native yarrow will thrive with water and will spread- so if you don’t want it to spread, apply neglect, and you’ll be rewarded with a prosperous, beautiful, native plant.

1 comment:

  1. Hi,

    Would you like to receive news releases and review copies of Princeton University Press's forthcoming birding and natural history books? Please contact me at jgood@brynmawr.edu for more information.