Monday, January 7, 2013

Naturalizing Within a Stand of Ornamental Grass

I continue to be fascinated with the popular horticultural efforts to create ornamental plant communities inspired by naturally occurring plant communities such as meadows. One approach that has interested me for years and that I have experimented with repeatedly is to create a sort of matrix of a clumping ornamental grass and then introduce compatible flowering plants. (So far the grasses I have used include Deschampsia flexuosa, Deschampsia caespitosa, Calamagrostis brachytricha, Sporobolus heterolepis, and Festuca ovina, and I just started playing around with Sesleria autumnalis which I think is promising.)  Getting the grass established first will help to get ahead of the weeds, and I love the sweep of the grass matrix and the challenge of finding the right flowering plants to insert.

Above is a picture of turf that is mowed only two or three times a year. As you can see yarrow has established itself nicely in a portion of this field and represents a simple form of what I am talking about, but it is a bit rough for a garden.

Above is a picture I copied from William Robinson's 1881 edition of The Wild Garden in which he suggested planting peonies in the midst of a stand of grass. I experimented with that idea myself as can be seen below.
As is so often the case, I think I could do a better job if I could start all over from scratch, but instead I will continue to tweak it to get just the affect I am looking for.
Above is my first attempt (1990) at this type of planting which I thought went fairly well but my work colleagues never seemed very fond of it. The grass is Sporobolus heterolepis along with the blooming Allium cernuum on August 6th. Belamcanda seed pods are about to open. I think this made a nice late summer display, and earlier in the year Allium aflatunense, Liatris spicata, and Hemerocallis flava added seasonal floral interest. One problem was the encroachment of the adjoining turf grass, and I guess the other was that it never looked "composed." Perhaps placed in a location with lower expectations of cultivated splendor it would have been better received.

Another project, still in development, is to create a little community on about a 300 sq. ft. terrace between two rock retaining walls. Above Verbena 'Annie' proved a pleasant surprise in this dry sandy site, growing nicely with Festuca ovina. Judging by how quickly it established itself the Verbena may prove to be a bit aggressive.
Below is the same planting with another pleasant surprise. After having killed Incarvillea delavayi a couple of times this Festuca ovina planting proved to be a place for it to thrive. I will continue to search for suitable companions to join this little community.