Selecting Exceptional Plants

The next future plants? Or not quite garden-worthy?

How great plantsmen use superior plant selection to elevate their designs 

Let’s face it: it’s entirely possible to create an elegant garden out of everyday plants. The highly sculpted gardens of the Belgian landscape design firm Wirtz International almost flaunt the fact that a large, diverse plant list is not necessary to create great design. Their serpentine coiled hedges, dreamy cloud-shaped boxwoods, and fluffy grass-covered mounds are an artistic declaration that less can indeed be more. No cutting-edge plants here: just boxwood, yews, hornbeams, and the occasional ornamental grass.

Even at a less grand scale, simple can be beautiful. I can think of no more elegant space than a simple gravel terrace underneath a beautiful tree. Who can ask for more than dappled light, the sway of a branch, and the change of seasons?

But at the same time, some of the best plantsmen in the world achieve success in part through discriminating taste in plant selection. They seek out not only the most vigorous plants, but also the most interesting selections. This discerning eye is one of the qualities that unite a diverse group of plantsmen such as Karl Foerster, Mien Ruys, Beth Chatto, Wolfgang Oehme, Henk Gerritson, Piet Oudolf, Fergus Garrett, Dan Hinkley, and Roy Diblik. Their gardens are legendary in part because of their ruthlessness in plant selection. And as a result, they made us see their plants (and gardens) in a new light.

Renowned plantsmen known for their discriminating plant selection

Consider Piet Oudolf: he is known for his rigorous trialing of plants before ever using them in a design. In the preface to Dream Plants, an excellent reference book by Piet and Henk Gerritson of the toughest plants, Noel Kingsbury describes Piet’s process, “Over the years he has grown a vast range of plants from seed list, collected seed in the wild, trialled innumerable plants bought in nurseries as well as those given him by friends and colleagues. Only a tiny fraction of these are judged good enough to be used in the gardens that he makes.” 

So is it possible to develop a discriminating eye for plants? One that will improve your own plantings? This fall I am looking at the flaws in my own garden. Many of the changes I will make focus on plants that just didn’t perform in my small space. So in order to learn a few lessons, I’ve been pouring over the planting plans and lists of several of these designers. The takeaways I list below are definitely more suited for the horticulturally adventurous rather than the casual gardener. But whether you consider gardening a quiet escape or an extreme sport, some of these points are worth pondering:

1. Take a hike: See plants growing in their community of origin

Andropogon virginicus var. glauca, a gorgeous blue grass not available in cultivation

To see a plant growing in its wild habitat is to understand it. Wild plant communities are not only beautiful, but they are short cuts to understanding the whole culture of a plant. Just by simply naming a wild plant community, you can probably make some assumptions about the pH of the soil, the annual rainfall of the area, and the type of disturbance that happened. Beth Chatto credited the idea of her iconic Gravel Garden to a coastal hike where she saw plants growing in dunes. Your own walks into the wild will embolden you to expand your own palette and create combinations that are different from any garden book available. 

2. Go hunting: Learn how to propagate your own plants

Here’s the deal: if you truly want to have a few plants that give your garden an edge, you cannot rely solely on the nursery industry to supply them to you. There are indeed some great nursery-bred plants out there, but the industry for the most part has to cater to what sells. Mail ordering from specialty nurseries is indeed a good option, but this can be very expensive. Trading plants with other adventurous gardeners is another way to get great plants. Seed exchanges offered through horticultural societies offer many rare and unusual selections. By far the best option is to collect seed or cuttings from the wild and propagate them yourself. A little training is required, but for the most part, plant propagation is relatively simple as long as you are patient.  Nancy Ondra of Hayefield has an excellent post on the basics of home seed germination.  

3. Don’t be dogmatic about native/exotic, straight species/cultivar

Hakonechloa macra & Echinacea pallida are superior straight species, while the cultivated Monarda is more garden-worthy

When it comes to plant selection, great plantsmen are often pragmatists, not crusaders. They are rarely ideological about where their plants come from or even how they are bred. At times they may favor wild plants, while at other times they prefer a cultivar. “We would rather have a vigorous monarda in our natural garden,” writes Oudolf and Gerritsen, “produced through a lengthy selection process (in other words, cultivated), than a wild specimen which degenerates into a pathetic pile of mildew in our climate.” Sometimes the superior plant is a straight species. Other times it is a cultivar. What makes a garden-worthy plant is not the plant’s pedigree, but its performance. This kind of ruthless meritocracy only allows the most vigorous, interesting, and worthy plants into a design. 

4. Look at the plant lists, not the glossy pictures

Imitation is indeed the sincerest form of flattery, so if you are looking to expand your repertoire, why not start by trying some of the plants of the great plantsmen. Most of them have a “palette” they use frequently, so some of their most used plants are likely all-star performers worth trying in your own garden. Pay attention to exact cultivars, too. 

5. Trial the plant yourself

And this is the point that separates good designers from great plantsmen: knowing a plant almost intuitively through years of gardening in different sites. No amount of internet research or word of mouth can replace the kind of deep garden knowledge that comes from propagating, growing, and testing a plant, not just on one site, but in multiple places. Knowing a plant’s tolerance gives you the confidence to plant boldly and take risks in unexpected ways. 

6. Form, texture, and resiliency trump flower

As I peruse the plant lists of many great plantsmen, one of the key qualities of these plants is the focus on form or texture, rather than flower color. As an inexperienced designer, I remember being initially unimpressed with many of Wolfgang Oehme’s favorite introductions. His love of Aster tartaricus, Pycnanthemum muticum, Eupatorium hyssopifolium, and Miscanthus ‘Malepartus’ were plants that did not initially seem that pretty or accessible to me. They were all unusual, different looking plants. But it was only through years of gardening and designing that I realized how wonderful, vigorous, and truly superior many of these selections were, especially compared with other similar species. Their best qualities exist in combination with other plants. 

7. Follow the best breeders

It helps to remember that a good portion of nursery breeding focuses on flower color or size rather than vigor or hardiness. Many new introductions come to market every spring, but few produce great plants.  For example, much of the Echinacea and Heuchera breeding in the last few years has produced interesting, but ultimately poor performing landscape plants. Of course, there are some really wonderful breeders and plant hunters looking for the next future plants. Dan Hinkley, Dan Heims of Terra Nova, Steve Castorani of North Creek Nurseries, Roy Diblik of Northwind Perennial Farm are a few of the bright spots in the American scene worth watching. 

8. Don’t be snobby, just selective

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Being selective does not mean being snobby about widely used plants. In fact, one of the marks of great plantsmanship is the ability to make a common plant look interesting by combining it in new and interesting ways. I always remember Christopher Lloyd’s use of the usually horrid Euonymus fortunei ‘Silver Queen’—a mainstay of suburban strip malls—as an anchor of the Long Border. But in his border, it is a perfect foil to the riotous border, giving much needed structure. It proves that good plants are, well . . .  good plants, even if they do appear in front of the gas station.

So let us celebrate the very best plants, whether they are common or cutting edge. Remember: ruthless pragmatism is ultimately more valuable than plant snobbery or moral idealism. Boring or under-performing plants can weigh down a garden. We may love our little plant babies, but our gardens will look better and perform more sustainably if we apply a coldblooded meritocracy to our plant selection. Interesting plants create interesting gardens.