Gardens Illustrated podcasts

Gardens Illustrated, the BBC-published British gardening magazine, offers some of the best gardening podcasts I've heard. Click this link to get to the GI podcast webpage. I particularly recommend the GI 2006 lecture, really more a long conversation with Anna Pavord, Beth Chatto, and Dan Pearson.

I've recently acquired an ipod, so I'll add posts to other outstanding podcasts, if I find them. Most podcasts from the good old USA don't seem to compare.

Garden Diary: Taking Stock

Douglas Tallamy's book Bringing Nature Home (see previous post) lists native plants of the Mid-Atlantic region with desirable wildlife value and desirable landscaping attributes. Since I do mix in exotics, I decided to see how many plants on Tallamy's list are in or surrounding my garden. Here's the list:

Shade and Specimen Trees
Acer rubrum
Betula nigra
Carya glabra
Platanus occidentalis

Shrubs and Understory Trees
Cephalanthus occidentalis
Chionanthus virginicus
Clethra alnifolia
Cornus alternifolia
Cornus florida
Ilex glabra
Ilex opaca
Ilex verticillata
Itea virginica
Lindera benzoin
Magnolia virginiana
Rhodendron atlanticum
Rhodendron viscosum
Rhus typhina
Sassafras albidum
Vaccinium corymbosum
Virburnum dentatum
Viburnum nudum
Viburnum prunifolium

Conifers
Juniperus virginiana
Pinus strobus
Tsuga canadensis

Vines
Parthenocissus quinquefolia

Streamside Plants
Acer rubrum
Betula nigra
Cephalanthus occidentalis
Clethra alnifolia
Magnolia virginiana
Platanus occidentalis
Rhodendron viscosum

Ground Covers
Carex plataginea
Podophyllum peltatum

Herbaceous Perennials, Dry Sites
Aquilegia canadensis
Arisaema triphyllum
Aster divaricatus
Aster laterifolius
Aster novae-angliae
Baptisia australis
Cardamine concatenata
Cimicifuga racemosa
Eupatorium perfoliatum
Geranium maculatum
Pycnanthemum muticum
Sisyrinchium angustifolium
Solidago canadensis
Veronicastrum virginicum

Herbaceous Perennials, Moist Sites
Asclepias incarnata
Aster puniceus
Chelone glabra
Eupatorium coelestinum
Eupatorium fistulosum
Eupatorium rugosum
Filipendula rubra
Hibiscus moscheutos
Iris versicolor
Lobelia cardinalis
Lobelia siphilitica
Lysimachia ciliata
Mimulus ringens
Monarda didyma
Penstemon digitalis
Polygonatum commutatum
Rudbeckia laciniata
Verbena hastata
Vernonia noveboracensis

Grasses, Sedges and Rushes
Carex vulpinoidea
Chasmanthium latifolium
Elymus hystrix
Juncus effusus
Panicum virgatum
Sorghastrum nutans

Ferns
Onoclea sensibilis
Osmunda cinnamomea
Osmunda regalis
Polystichum acrostichoides

Some of these are cultivars, not local species. I also have a number of other plants I believe are native, but they are not on Tallamy's list. Some, I know, are native to this continent, but possibly not to the Mid-Atlantic area. This brings up the much more complex subject of regional differences, and of local provenance vs. "native" in a very general sense. A subject for another day.

The Self-heal (Prunella vulgaris) in the photo above, for example. Is it a native in this area, a native of another region, or an alien that's been here so long we think of it as native? I have to admit I don't know.

Nor'easter

Everything's been flattened. A Nor'easter raced by last night. Mostly sleet and freezing rain. High winds predicted this afternoon. This follows a lighter freezing rain a few days back. If the temperature rises fast enough, collapsed grasses may right themselves. We'll see.

Rudbeckia maxima and monarda stand upright, unscathed.

The dogwoods' icy cover shines even in this dull light. Flocks of birds are everywhere. What brings them out in this cold rain? The bent over grasses look like swatches of water colors showing the fawns, oranges, russets, muted browns, and blacks of winter.

Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens by Douglas W. Tallamy

I'm a gardener, and I don't want to grow only native plants. This book makes me stop and think. Douglas Tallamy makes the best case for use of native plants I've read. I recommend it without reservation.

Tallamy writes with grace and humor. He makes it easy to follow his arguments, uses copious examples to relate his ideas to the natural world we all know, and uses down-to-earth anecdotes to illustrate his points clearly. The book, even with its many, for me, unpronounceable binomial Latin names for a multitude of insects, is an easy read. I finished it in two days, while busy with work and many other chores.

Simply put, the book's message is this. All life on earth, except for some recently discovered, relatively rare forms that take energy from volcanic vents in the ocean floor, depend on energy from the sun that plants convert into food through photosynthesis. Most of that solar energy is made available to higher life forms through insects that eat plants. With the exception of a few direct herbivores such as cows, all other higher forms of life either eat insects (most birds) or eat other animals that eat insects (hawks eating sparrows), and so on up the food chain. The productivity of an environment, literally the weight of biomass produced in a given area, is directly related to the insect population, and the variety of wildlife - number of species of birds and other wildlife - is also directly related to the numbers and varieties of insects living there.

Research now clearly shows that native insect populations cannot be sustained by most alien plants. Our insects have co-evolved with native plants over millions of years, and most have highly specific preferences for certain plants as food. As Professor and Chair of the Department of Entomology and Wildlife Ecology at the University of Delaware, Tallamy has access to research that tells a disturbing story. With increasing urbanization and suburbanization, loss of large forest and natural areas to development, and transformation of a vast portion of the continent into ecologically sterile lawn, we can look forward to mass extinctions of insects, birds, and other forms of life that could surpass the mass extinctions caused by the great meteorite impacts long ago.

Without the literally innumerable varieties of insects that constitute the first step in transfer of solar energy into life, massive losses of species will occur in the not too distant future. Many such extinctions are already under way.

Tallamy has statistics to back up his message. Native oaks, for example, support 517 lepidoptera species, willows, 456, birches, 413. In contrast, alien Clematis vitalba is a food source for 40 species of herbivores in its homeland, but only 1 in North America. Another example, Phragmites australis supports 170 species in its homeland, but only 5 species on this continent. Unfortunately, insects can't evolve to adapt to alien species in time to save our threatened populations. Evolution takes place over millions of years. Although the Norway maple has been on the North American continent for going on 300 years, and has become the predominant shade tree here, it still has not become a productive part of our native ecosystem. Instead, it is rapidly displacing native species of maple.

Lest you fear increasing insect populations will decimate your garden, Tallamy reassures his readers that balanced populations of insects and predators will keep each other in check. The key is to plant in sufficient variety to maintain a stable supply of insects as food, as well as birds and other creatures that feed on the insects.

Tallamy urges readers to do what they can to eliminate invasive alien species, to use native plants, to replace sterile lawns, which consist of two or three alien grass species that serve as a food source for little more than Japanese beetle grubs, with sustaining native plant refuges. He urges those who live in suburbia to plant native shade trees, even groves, to plant natives along lot lines to begin reestablishing productive areas where insects can successfully reproduce and thrive, and where their predators can find security and cover. If you have many insects, you'll also have many birds.

Like most people, I have an aversion to what I consider ugly, even frightening insects. I find it much easier to look at pictures of pretty butterflies than spiders and sawflies, but I learned a lot about the insect world while reading this book and looking at its pictures. And now I have enough knowledge to want to learn more, and to better understand how the natural world of my garden works.

I doubt I'll be able to entirely eliminate plants of foreign origin from my garden, but I'll try to keep a much better balance of natives to aliens (mostly natives), and practice more sustainable gardening in the future. And I'll certainly work to try to convince others to reduce lawn size and incorporate native plants into their landscapes.

The book is available through Timber Press.

For an opposing position, see my posting of October 2006 (Is planting Dahlia Bishop of Landaff an immoral act?). I'm still wrestling with with this one.

Woodland groundcover

Helleborus foetidus (see previous post) brings to mind a highly imaginative groundcover I photographed on the New Hope garden tour three years ago. The day was rainy, but mostly of the gentle kind that reflects light from the sky and highlights color and detail. On a wooded hillside, almost hidden from view behind a screen of evergreens, this striking combination of Helleborus foetidus, Japanese painted fern (Athyrium nipponicum 'Pictum') and Epimedium had merged into a subtly mixed carpet of shapes and textures.



I've wanted to duplicate this planting since I first saw it, but time passes and there are just too many things to do in a garden. And, to be true, I'd need several hundred dollars to get this kind of effect quickly.

Helleborus foetidus

One of my favorite perennials, the Stinking - or Bear's claw - hellebore (Helleborus foetidus) is coming into its own as the night temperatures drop into the 20's. Plant it where you can easily see it from inside the house, and watch as it comes into all green bloom in winter. It may appear to suffer in extremely cold, harsh spells, but will amazingly resurrect itself on warm days.


I put this one just outside the sliding doors to the terrace. It will get morning light on bright days, plenty of water from the drip line of the roof, and good drainage since it's planted in gravel. If past experience with this plant proves true, it will self seed, forming a colony in a year or two.


And it does not stink at all.

Garden Diary: Fullness

Already late November and autumn still shows in seed, stalk, tussock, falling leaf... brown, gold, russet, almost black.

The dirt is wet and cold and growing colder. Sun is low, barely clearing trees encircling the garden and light is broken almost all day long, hardly ever straight on and bright.


This is the season of seedheads and dry grasses still anchored in the earth, stirred by occasional wind, hinting return next spring or in more distant summer. Rain, snow will fall, ice form, rarely crystalline ice that makes jewels of empty seed pods and broken stems. Dark clouds, fog, dreary days, night.

Then with a tilting earth, a higher sun, warmth will return to bring back green larger and more numerous.

Garden Diary: The Front Garden

The "front" of our house on Federal Twist - the facade facing the road - is actually the back. It presents a simple wall to visitors. The real front of the house is at the back, where an unbroken wall of floor to ceiling windows gives onto the main garden, and surrounding it, the woods.


The choice of where the front garden would be was predetermined by a barren gravel circle at the front entrance. The house is about 165 feet from the road, with open woods in between, so screening wasn't absolutely necessary, but added privacy was desirable since none of the windows are covered. Even more important, I wanted to create a focal point and add visual interest. The photo above is the front garden, still in progress, this past summer. The second photo shows the original front "garden" when we purchased the house in fall of 2004.

The house is a simple, shed-like structure, at least viewed from the side facing the road. The only notable front views out are from the kitchen window and sliding doors in the dining room. The original view out was onto a circular graveled area about 28 feet in diameter, with a mostly dead crab apple, a couple of scraggly burning bushes (Euonymous alatus), a line of arborvitae, and two Sedum spectabile 'Autumn Joy' eaten to the ground by deer. To the side were two rotting, frequently amputated Japanese cherries.

Looking out toward the road, the view of the woods was not without interest but also not particularly notable. We needed something to look at from inside the house, to provide additional screening in place of window and door coverings, and to make the facade facing the road more welcoming - something that would screen our uncovered expanses of glass, providing privacy, while signaling a greeting to visitors and giving clear direction to the house entry, which was hidden at the far end of a dark porch.

After we cleared most of the area, the first plant to go in was a large Ravenna grass (Saccharum ravennae), which I split in two - a discard of our friend Roberta, who found it overwhelming in her small Lambertville garden (I had put it there). This was in May of 2005. You'll have to click on the photo to see the two grasses in the wide expanse of gravel.
In the top photo you can see how, once the grass matured, its fountain-like shape and large size made it a welcoming gesture to anyone turning into the drive.

Planting continued through that summer of 2005, and by August was essentially finished. I used several Miscanthus (Gracillimus, Yaku Jima, Adagio), Joe Pye Weed (Eupatorium maculatum 'Gateway'), Persicaria amplexicaulis 'Firetail', catmint (Nepeta m. 'Walkers Low'), Sedum 'Matrona', Bluestocking monarda (Monarda d. 'Blaustrumpf'), a small lilac (personal request from Phil), Pennisetum a. 'Moudry', a few Japanese Blood Grasses (Imperator cylindrica rubrum), Aster laterifolius 'Lady in Black', Lychnis coronaria, purple smoke bush (Cotinus coggygria 'Royal Purple'), and an inkberry holly (Ilex glabra) to anchor one corner. I scattered seed of Verbena bonariensis and bronze fennel, and I kept two of the arborvitae, the legacy Sedum 'Autumn Joy', and self-seeded Eupatorium rugosum (a really invasive thug I'm now trying to eliminate). The first year planting looks scraggly but by the next spring it had filled out well, as you can see in the next three photos taken in late June 2006.


In 11 months, the Miscanthus, Joe Pye Weed, and Saccarum had grown into substantial islands of graceful foliage and the Nepeta 'Walkers Low', just passing its early prolific bloom, had relaxed into the contours of its surroundings like an old hand.

All of this was working on the large scale, creating a new space and transforming the house on Federal Twist into a place with a little more mystery than before.


On the smaller scale, details of flower and foliage shape and texture began to add interest - monarda busy with bees and butterflies ...


Purple smoke bush graced by the magenta of Lychnis coronaria ...


and the smoke bush again, with cat mint and Sedum 'Matrona' against a hedge of burning bush.

Under the gravel is clay, same as everywhere else at Federal Twist. Unlike the main garden at the back, this one is raised above the surrounding grade, so drainage is much better. Though it makes a very heavy planting medium, the clay is rich and, after only two years, it looks like some of the grasses will need to be divided next year.

To finish, a couple of views from this past summer ...

Garden Diary: Slow Gardening

This garden is slow to take shape. I have to compare photos from 2006 and 2007 to realize the progress. The first photo from late June last year shows a rather desolate area, with the spot where I burned debris from tree felling clearly visible at back.



This year, with a deer fence up, another year's growth, and another long season of planting, the picture is dramatically different.



Closer views show the plant matrix clearly emerging and, for the first time, giving a substantial show of texture and color. (Click on the photo above to see the detail.) The Joe Pye Weed, Rudbeckia maxima, water irises, and Lysimachia ciliata 'Firecracker' have come through two seasons with great tenacity in this difficult environment...




while the monardas (Blaustrumpf and Jacob Cline) and Liatris pycnostachya are new and only next spring will tell how they survive or thrive.



Think of the garden as the bottom of a bowl, with surrounding dark forest - a darkness that seems to "swallow" color. Brightness is needed to stand out against the dark trees, and the monarda do that well, especially the red Jacob Cline.



Even better for contrast against the dark are Rudbeckia maxima, with bright yellow blossoms on 6-foot stalks. And their large glaucous blue leaves are a plus. I added 14 more this fall. If the Silphium terebinthinaceum, planted as plugs 18 months ago, flower next year, they should add to the mid-summer brightness.



The lysimachia 'Firecracker' thrives, and I believe can outcompete the most aggressive weeds (not the rushes!) so I plan to add a substantial new planting next spring.



Here it contrasts with rudbeckia stems in the foreground and various panicums further back. All of this in heavy clay, wet for 10 months out of the year.

Saco Heath

On a two week trip to Maine, we visited the Saco Heath. It's the southernmost raised peat bog in North America. According to the guidebooks this is the only place where Atlantic cedar is known to grow in a domed heath. More later.

Here are some photos.