Warfare in the garden

It may look rough, it may look bare, but this is the time of the year to see what's happening at soil level. It's easy to see which plants are competing with their neighbors, which plants may be getting the upper hand, where the problems are. Here is a sweeping view of the garden from the hydrangea "bower" (well, bower-in-progress) on the far side of the garden.

The area I'm headed for is the inside of the curve in the path, on the right side of the next photo.

Here ... though this may look a mess, gets to the heart of the kind of gardening I'm doing at Federal Twist. There isn't much open ground in my garden; I've planted to try to prevent that, using plants as a living mulch to limit undesirable self-seeding, to suppress weeds, to control how the garden grows and how the planted areas interact, to the extent that's possible.

But here I created a small piece of open ground--originally to raise the soil level so I could grow Eryngium yuccafolium (Rattlesnake master). I also wanted to try using Bergenia and a European bunch grass, Sesleria autumnalis, as groundcover. I can't say that was successful, not yet anyway, so I decided to see what I could do with seeding. I like the early umbelliferous flowers of Poison hemlock (Conium maculatum) that grows along the roadsides nearby so I collected seed and scattered it here. It's the plant with lacy, carrot-like foliage, in its third year now. (Yes, this is the same plant used to put Socrates to death, so it's of alien origin.) Then Ironweed started to self-seed. And thistles, and other interlopers.

Not wanting to replace this natural mechanism entirely, wipe it out and put in some plant combination that I know will dominate and rule the area (though that option remains open), I'm letting the self-seeding continue, but managing the process by weeding out plants I find pernicious or otherwise undesirable.

Unstable and subject to continuing change as this area is, it requires management throughout the growing season. The Poison hemlock, for example, grows rapidly and blossoms in June, then promptly dies and becomes a rather unattractive, brown skeleton. I cut and remove it, and let the later blooming Eryngium and Vernonia take over the space. I'll eventually want to find a stable condition, but don't yet know what that will be. The goal will be to cover the ground with only desirable plants.

So it goes on the larger scale, though the garden as a whole is much more stable because it's full of large, dominant plants. The apparent empty spaces around the red logs isn't empty at all. I've planted several clumps of Miscanthus giganteus to screen the view of the deer fence behind and to provide a visual boundary to the garden, as well as other kinds of miscanthus, and on this side, Panicum 'Dallas Blues' and Petasites japonicus for variety of texture and color, and for the practical purpose of covering ground.

Above are the early flower spikes of a hybrid Petasites I use massed in two large areas. Not much can compete successfully with Petasites. Below are the flowers of Petasites japonicus, similar to the hybrid, but with round rather than angular leaves.

These willows, Salix sachalinensis 'Sekko', through shading and root competition, also dominate their ground.

Some other plants seem to dwell undisturbed above the competitive fray, peacefully apart from a kind of warfare that exists at ground level. Lindera benzoin (Spice bush) is one such plant. It fills the woods around here, and now as you drive along the roads or walk, you see clouds of Lindera blossoming, almost like yellow flurries of snow.

It's another kind of actor, seemingly able to adapt successfully to just about any kind of competition. If you follow the rule that there are three kinds of plants--ruderals (pioneer plants that quickly cover bare ground), competitors, and stress tolerators--this must be a stress tolerator.

Here, the field of battle.

Spring walkabout

Til now, posts on these garden walkabouts have only appeared in summer and fall. Spring just wasn't a good time in the garden on Federal Twist. The site is cold and wet, and most of the perennials that thrive in these conditions get a late start. Only this year is the garden beginning to show significant early season interest.

A part of the change is simply maturity. The communities of plants have had a few years to grow together, forming large masses varying subtly in height, texture and color. I've also added shrubs and small trees--while keeping the largest areas open for perennials only, essential for easy planting management--which provide a sense of scale, and a few evergreens, whose dark silhouettes contrast dramatically with the lighter spring greens and golds of the herbaceous perennials.

Right now the morning sun backlights much of the foliage, looking for all the world like fractured stained glass, and the broken light filtering through the partially leafed trees imbues the space with a sense of peace and optimism. The wind gently whispers; humming birds alight in the aged dogwoods that screen the garden view from the house. It's a most pleasant, but of course, transient scene, a momentary Eden which passes quickly enough ...

... passes, for me that is, to the "mechanics" of the garden, for example, structure, contrast in color and form, garden management practices ...

The graveled paths encircling the planted areas, like the dark evergreens, give a visual weight to the garden ... the stone walls, a hard mineral background contrasting with the soft vegetable tissues ...

It's far too early for the pond to be overgrown with vegetation. For a while, the there's a clean edge and the water surface reflects the sky, a distant dogwood (below), or serves as a simple foil for Camassias planted around the pond's perimeter. It's taken three years for these to settle in and get going. Now I see I should plant more, and in other parts of the garden, especially since they echo the form of the hybrid Petasites flower spikes, which are blooming at the same time.

Less photogenic, but essential to understanding another aspect of garden mechanics--the maintenance or management process--are the spreading mats of perennials. Here, an example of matrix planting, Symphyotrichum puniceum (formerly Aster puniceus or Swamp aster) has formed a wide circular mat that out competes many of the less desirable grasses.

And here, large masses of Filipendula rubra 'Venusta', which have been a strong and stable presence for several years now, even though the soil is crowded with a variety of competing plants. If you want to manage large areas rather than "garden" individual plants, you'll have to learn what plants are appropriate to your conditions. That knowledge isn't always easily available, so a willingness to experiment, and to fail, is necessary. I used to have a community of Liatris pyncnostachia mixed in with the Filipendula. It was a stunning combination, but the Liatris gradually succumbed to competitive pressure and has all but disappeared.

"Nature's first green is gold," Robert Frost, that great and cynical observer of Nature, wrote. To build on that golden theme of early spring, I added three Sunburst Honey Locusts (Gleditsia triacanthos 'Sunburst) in the early days of the garden. They've not grown much, but each spring their brilliant foliage beckons like finely hammered artifacts of gold. I don't want them to become large trees; these golden poles are fine.

Then I discovered the wonderful non-native Euphorbia palustris, which I've scattered around to create more pools of golden color, and I may add more. Note here too (below)  the thickly growing mass of violets--functioning here as another important garden management tool--ground cover (matrix planting again).

The more distant view from the raised terrace outside the house shows fine detail to the naked eye but not to the camera. What you do see is the void in the forest in which the garden exists, and that void is a defining characteristic of this garden:  a clearing in the woods, a safe place, though a tentative safety that might vanish in the blink of an eye.

Gardens are like that, constantly changing, threatening loss of control, running away from you if you aren't paying attention.

Speaking of competition

Here is Pulmonaria 'Samourai', a durable, silver-leafed hybrid from Tony Avent's Plant Delights nursery. I planted the large one two years ago, then added two more last spring. Sweet woodruff (Galium odoratum) spread from a colony across the path and is now making a pretty background for the Pulmonaria. (Pretty, but this is certainly an invasion.)

Here we may have plant war in slow motion. The Pulmonaria appears to be extremely sturdy and durable. I know the Galium is a rampant spreader (which I accept, even want, because it's such a good groundcover). Who will win? Or will the plants co-exist, at least for a few years?




The last photo shows another invader, Eupatorum rugosum, another attractive, four-foot native that self-seeds like crazy, in the lower center. This must be plucked out.

Garden Diary: Competitors, Stress Tolerators & Ruderals

Having worked for several years to establish a matrix of plants that will be at least partly self-sustaining, I can see some progress this spring. At this stage, I'm still keeping pretty much anything that covers the ground and prevents random germination from the seed bank.

Thanks to Noel Kingsbury's books, I now know I'm trying to orchestrate a bunch of competitive perennials, stress tolerators, and those opportunistic ruderals, plants that take advantage of any open ground in the early stages of a planting, where they thrive until extinguished by larger or more competitive neighbors.

The picture below is of one of several Filipendula rubra 'Venusta' that have settled in well and are slowly spreading. I'd judge these to be moderate competitors; they are slowly covering more ground, but they don't self-seed at all.

Next is another sample of a matrix planting, primarily Petasites hybridus, native Equisetum arvense, native Lysimachia nummularia, and at the far edge, Carex muskingumensis, Darmera peltata, cimicifuga (actea), and thalictrum. The equisetum, though highly invasive and a competitor par excellence, will wither away in a month or so, leaving room for a really disgusting ruderal, Japanese stilt grass (Microstegium vimineum), to intrude.

The vertical wands rising from the petasites are flowers, which you can see more clearly in the next photo.


The next two photos show views turning clockwise about 150 degrees.


The more "finished" matrix above contrasts markedly with another garden view below. Here is where the filipendula I opened with grows, along with other large wet prairie perennials such as Eupatorium purpureum (Joe Pye Weed), Liatris pyncnostachya, Rudbeckia maxima, assorted wetland irises, sanguisorbas, miscanthus, panicums, and other plants too numerous to list. Obviously there are no early perennials to make an attractive matrix planting here. This area won't reach its potential until July.


Here is where I need to develop spring plantings that will give interest and good coverage early in the season, then disappear, or at least tolerate shade cast by the larger perennials later in the season (spreading stress tolerators is what I need). More bulbs (stress tolerators) can certainly help, especially daffodils. Native persicarias especially like this area as the season progresses, so some early persicarias, such as Persicaria bistorta 'Superba', may be helpful. And, of course, a blanket of astilbes would give both color and interesting, long-lasting structure.

I'm open to suggestions.