My book and web site

Check out my book, The Sustainable-Enough Garden, available on Amazon, and the book's web site at www.thesustainable-enoughgarden.com. See more plant photos on Instagram.

Monday, August 14, 2017

How it should be done

Yes, a garden can be both sustainable and beautiful. My faith in this ideal got a big boost Saturday when I visited garden designer Robin Wilkerson’s enchanting home garden in Lincoln, Massachusetts. She opened her site to visitors as part of a native plant tour organized by the Ecological Landscape Alliance.


The entrance to Robin's sustainable garden

      Robin’s house and garden sit on old farmland that had been taken over by nonnative invasive plants. For 20 years she has been reclaiming expanding portions of the lot for her organic garden, tearing out unwanted plants and sheet mulching with cardboard and wood chips to smother unwanted vegetation. She grows a large vegetable garden, grapes, berries, and numerous fruit trees.

Beds of bird- and pollinator-friendly shrubs and perennials lead to fruit trees in the background

    Unlike me, she’s resisted planting tall trees that would shade sunny areas. Her flowers enjoy full sun. There’s also a shady woodland section. 


    I had attended a workshop Robin taught at New England Wild Flower Society’s Garden in the Woods on native shrubs for garden use. Her enthusiasm for these plants was contagious and reinforced by a tour of the garden on a lovely June day. Afterward, though, second thoughts set in. 


    Many of the plants she’d showcased had medium-green, medium-sized leaves. They might have pretty fruits and bright fall foliage, but their flowers were often small, off-white, and not very eye-catching. I thought that a garden of these shrubs would look like a typical New England woodland edge, generally pleasing but not particularly striking or ornamental.


    Seeing Robin’s garden, though, I suddenly got it.


A peach tree, ornamental banana, and hanging basket of calibrachoa blend with native honeysuckle and phlox

While supporting biodiversity and welcoming wildlife, she’s combined natives and nonnatives in a harmonious blend of flowering plants from New England and around the world. The natives she’s planted are shown at their best through thoughtful combinations of shapes, sizes, and leaf colors and textures. 

It's all in the design

    She has large, thriving patches of a long list of pollinator-friendly plants. Plentiful fruit beckons to both humans and birds. 


Peaches!

She’s lined the lowest point in the lot, the back border, with a barrier made from pruned twigs and branches; 

This homemade fence provides shelter for insects and other animals

in addition to demarcating the lot line and preventing erosion, this provides a home for insects and other animals. For birds, she keeps several dead trees topped at around 20 feet standing behind the garage. These snags are valuable to woodpeckers and others that feed on insects beneath the bark and build their nests in tree cavities.

Dead trees offer food and habitat for birds

    Insects were everywhere. In addition to the many bees working flowering perennials, butterflies were wafting all over the yard, 


Black swallowtail nectaring on a tithonia flower

and I spotted a hummingbird moth. That was just while strolling around gawking at the flowers; I’m sure closer observation would find that this garden hosts a full range of insects in dynamic balance.

    Robin’s is the kind of garden I aspire to. The visit immediately got me thinking about how to emulate her dense plantings and thoughtful combinations of natives and exotics. Next, the front yard!

Sunday, August 6, 2017

Let it rain

What a lush garden year we’re having! Last summer’s gardens were parched by drought. This summer the Northeast has been blessed with plentiful rain. 

Foliage is thriving thanks to plentiful rain

As of August 6, we’d had 30.83 inches of precipitation in the Boston area in 2017, well above the average of 25.88 inches by this date. You can probably see the difference in your garden; I certainly can in mine.

    Why should that be? What makes rain better for gardens than irrigation? We run a sprinkler irrigation system, so unless I cut back on scheduled watering, my plants should be getting enough water even when it doesn’t rain.


Water beads on a giant elephant ear leaf

    There are limitations to even the best-designed irrigation system. Ours is set up in 12 watering zones. Twice a week, sprinkler heads pop up in the early morning and start spraying in a programmed sequence, controlled by a computer in the basement. A rain sensor prevents watering when there’s been adequate rain. With this system, I lavish a lot of water on the garden, sometimes more than my conscience tells me I should.

    Theoretically every plant gets plenty of irrigation water, but in practice, I’ve learned, it’s not that simple. As the garden has matured, shrubs have grown wide and tall, hogging the spray of water and creating dry shadows behind their bulk. And the arcs described by the sprinklers’ spray don’t fit exactly to every angle and curve of plantings. Inevitably some patches get less irrigation.


    Beyond falling evenly on the whole garden, rain conveys numerous advantages:


Lots of rain is helping this St. John's wort get established

•    Whereas irrigation water contains dissolved minerals, including calcium, magnesium and sodium, rainwater is “soft” and mineral-free. As a result, it pulls nutrients by diffusion from where they're bound in the soil, making them available to plants’ roots.
•    Rain water is acidic, which promotes release of micronutrients including zinc, manganese, copper and iron that plants need. Most of my garden soil is acidic already, but there may be alkaline areas where concrete paving leaches lime. Acidic rainwater is especially beneficial in those spots.




Soil next to sidewalks may be alkaline

•    Rain falls at 20 miles per hour, penetrating soil better than irrigation water, which falls at 5 mph.
•    Rain is saturated with air, so it oxygenates soil. That’s good for plants
•    Rain contains nitrogen in the form of nitrate and ammonium from the air. This nitrogen becomes available to plant roots and promotes growth.



Big canna leaves can use a boost from extra nitrogen in rain

•    Rain doesn’t contain the chlorine that comes with treated drinking water. Chlorine inhibits plant growth.
•    Rain flushes salts (such as road salt) that inhibit growth through the root zone and washes mineral deposits, dust and pollutants off leaves, making for more effective photosynthesis.


The proof is in the pudding. The garden looks happier this year with more rain. 



New plants I added in June and July are surviving, despite the heat. Just watering them might not have been enough if it hadn’t been for well-timed, frequent rain.

Sunday, July 30, 2017

The native (hemlocks) are dead. Long live the natives!

Remember those hemlocks I removed to avoid spraying for hemlock woolly adelgid? 

All that's left

They left two big gaps in the garden’s tree canopy that weren’t there before. It’s disconcerting seeing fresh wood chip mulch where evergreen branches used to sweep the ground.

    Last week I finished planting new trees and shrubs in the newly opened spaces. 


For now, small plants and lots of open space

The hemlocks were native to eastern North America. I wanted to replace them with other plants from our region to offer food and habitat for native insects. 

    Between the vegetable bed and compost bins, two hemlocks used to stand along the side fence. I planted two conifers to replace the visual barrier the hemlocks provided. A northern white cedar, also called arborvitae (Thuja occidentalis ‘Smaragd’) will eventually grow 15 feet high and 6 feet wide.

 
Northern white cedar is native to our area

    A small white spruce (Picea glauca conica) went in nearby. This tree ranges across the northern reaches of the continent. You may know it as dwarf Alberta spruce, the little conical potted trees that are often sold as container plants or live Christmas trees. 


This white spruce stays small because it's grown in a pot

It starts small and grows slowly at first, but someday this spruce’s height may reach 10 feet.

    The dense foliage of both these trees provide year-round shelter for birds and mammals. Birds eat the seeds and forage for insects among the branches.


    In the same area, I added an American black elderberry (Sambucus canadensis). Doug Tallamy, the entomologist author of Bringing Nature Home, lists this small tree as highly desirable for providing native insects with nectar and leaves they’re adapted to eat. Birds will also enjoy its copious black fall fruits.


Elderberries

    In view of the vegetable bed, I planted a sweetshrub, also called Carolina allspice (Calycanthus floridus). Its distinctive dark red flowers are reputed to have an intoxicating sweet, fruity scent that attracts insects. 


Sweetshrub has curious dark red flowers

I also planted a mountain laurel (Kalmia latifolia 'Elf') with pink buds and white flowers. I love mountain laurel’s freckled blooms, and Tallamy lists this shrub too as a boon to native insects.


An older mountain laurel blooming in June

    In a back corner of the yard where three hemlocks used to grow, I put in two inkberries (Ilex glabra ‘Shamrock’). I’m hoping this bird- and insect-friendly native evergreeen will prove to be a tough, reliable substitute for nonnative boxwood (Buxus sempervirens).



Boxwood
Inkberry




    Nearby in a spot visible from the kitchen window, I place a spicebush (Lindera benzoin), another of Tallamy’s choices that’s praised for its handsome yellow fall foliage.


Spicebush in fall--photo by tgpotterfield

    In case you’re wondering, I did find some of these young plants at the shop at the New England Wild Flower Society. This means they were grown without pesticides, so they definitely weren’t treated with neonics. I bought three at a sale at a local nursery. I can’t be sure those are neonic free. They don’t attract pollinators, though, so I hope they won’t sabotage the yard’s insect population.


    I’m looking forward to finding out whether these natives will flourish. If they do, they’ll join an expanding list of plants that welcome a broad variety of insects and birds to the yard.


Native purple coneflower
 

Sunday, July 23, 2017

Neonics reprised

Beekeepers are spreading the word: neonicotinoid pesticides are bad news for honeybees. A Boston Globe story last week about bee-friendly yards spotlighted the problem. While choosing native plants is a help, beekeepers interviewed emphasized that you undo your good work if you apply toxic pesticides on your property—or if someone nearby sprays these chemicals.

Black-eyed Susans help pollinators--but not if they're treated with toxic neonics

    Friends of Earth and its supporters are asking EPA administrator Scott Pruitt to ban one of the neonics, imidacloprid. The National Pesticide Information Center at Oregon State University reports there are 400 products sold in the US containing this pesticide in various forms: liquids, granules, dusts, and water-soluble powders. A quick search turned up brand names such as Temprid, Maxforce, and Bayer Insect Control. 


    So far the EPA has declined to ban agricultural use of imidacloprid. Plants sold in garden centers may be even more of a problem. 


Tempting, but garden center plants could be toxic for pollinators

They can be treated with the pesticide at 120 times the concentration used on farms. Because the neonics dissolve in water, they migrate into all plant tissues and can contaminate surrounding soil. They’re slow to degrade and can affect your garden for years to come.

    As garden center customers, we have reason to feel betrayed. We’re encouraged—urged—to buy pollinator-friendly plants. Wouldn’t it be reasonable to expect that those plants won’t kill pollinators?


    Beekeepers are of course most concerned about honeybee die-off. In late June, a beekeeper in Rehoboth, Massachusetts lost more than 60,000 bees. Knowledgeable observers say this loss has the hallmarks of pesticide poisoning. Bee scouts go out each morning to find sources of pollen and nectar. They return to the hive to share their information. The Rehoboth bees seem to have followed their scouts to a nearby food source contaminated with pesticide.


A contaminated food source can kill a whole hive--photo by Shawn Caza


     This is the kind of effect neonicotinoid spraying can have. A homeowner could have used a pesticide product according to label instructions, or worse, could have applied more than instructed or sprayed at a windy time when the spray would be carried to surrounding areas. The result: bee genocide.

    We hear most about honeybees, but there are 400 native bee species on the job too pollinating our food crops as well as other plants. 


Bumblebees are important pollinators too

Moths and butterflies also do this work. Neonics threaten all these insect pollinators. 

    Since becoming aware of the neonic problem this year, I’ve been working hard to avoid bringing home any neonic-treated plants. Plant purchases from previous years may already be spreading toxicity on my land. I searched for untreated seeds, or at least seeds sourced from European countries that don’t allow neonic treatment. I found places to shop where sellers guarantee their seedlings are pesticide-free, if not fully organic. But I had to avoid my favorite garden center, because they’re still buying neonic-treated plants.


Stokesia from a pesticide-free garden center

    Big retailers such as BJ’s Wholesale Club and Home Depot have already pledged not to sell neonic-treated plants. It’s high time that local garden centers did the same.

Monday, July 17, 2017

Energy conservation--mine

I spent much of last weekend bashing out a new slide talk for garden clubs. When I got home Monday from presenting it for the first time, what I most wanted to do was get out into the garden. I’d been harboring some resentment about spending nice days indoors working on the talk, although this was totally due to my own procrastination.

Stuck inside looking out
 
   The only downside of starting work in the garden at two in the afternoon was the outside temperature. It was in the high eighties. My motivation to work outdoors drops off sharply when the temperature passes 80. On cool spring and fall days, my idea of heaven is to be out in the garden. In summer heat, not so much.

In May, it's great to be outside

    I’ve certainly got sweat equity. I’ve put in many hours toiling over the vegetable garden under the hot sun. The only reason my skin in the game isn’t lobster-red is fanatical application of sunscreen. But when it’s hot and there’s no shade, gardening stops being fun and becomes just hard work.


I can relate

    This makes me feel like the consummate wimp, of course. People in Phoenix and Savannah probably don’t let a little heat keep them from tending their gardens. I recently heard an Arizonan describe getting up at 3:00 a.m. to do her outside chores before the 120-degree heat of the day sets in.


    That’s the approach I’ve decided to try. I won’t be getting up before dawn. But if I can be in the garden in the relative cool of 6:30 on days when the temperature is heading for the nineties, I can put in a good two hours before wilting.


Sunrise at home isn't as alluring as in Banff

    Part of this new plan is a liberating decision not to carry out my usual morning routine. No reading the paper over breakfast, just a quick cup of tea. Sunscreen on my face only. The dog can come outside with me, but she’ll have to wait for her walk.



Later

    So far I’ve done this twice, when I had work to do on my new planting project that couldn’t wait, but the weather wasn’t cooperating. Both times have been fun and productive. By 8:30 or 9:00, the day already felt rich with accomplishment.


    What does this have to do with sustainable gardening? A gardener’s energy and enthusiasm are finite resources too, like fossil fuels and peat moss. If sustainable gardening is such a harsh mistress that it demands working in the garden at the hottest time of the hottest days, it’s likely to find few lasting converts among home gardeners. 


 
Catching more gardeners with honey


    Monday afternoon my desire to plant shrubs trumped the heat, but the sweat running down my face reminded me of why early morning gardening had seemed like a better idea. 

  
    In deciding what we’ll to do to be part of the solution for environmental problems, each of us makes our own calculations. How much time, energy, money, and hard work are we willing to invest?  We might as well be realistic about what we expect from ourselves.

Sunday, July 9, 2017

Better than lawn

It took longer than I anticipated, but this week I finished planting my new perennials--and two shrubs--in new mostly-native beds next to the deck. They made it into the ground none too soon. Despite frequent watering, they were close to broiling where they stood, in planting position, in their containers in the July heat. 


Roots in the ground just in time

     The layer of black loam the contractors had spread was just starting to sprout weeds when I eked out a thin layer of pine-spruce bark mulch from seven large bags from the garden center. It didn’t feel right using purchased mulch, but last year’s leaf mulch was all gone.

     I was standing in the kitchen looking out over the new beds when I had an attack of buyer’s remorse. Had I made a terrible mistake? Now we won’t be able to seat guests in lawn chairs on that erstwhile patch of grass. 


Studying on the lawn circa 2003

They can sit on the wide bluestone path, or we can put chairs on the lawn circle that’s farther from the house. But a party tent over the deck is no longer an option. Had I spent money, fossil fuel energy, and many hours of work in the hot sun on a folly?

     While I was fretting about this, I noticed a swarm of bumblebees eagerly working a new St. John’s wort (Hypericum ‘Magic Universe’). The yellow flowers were already open, and the bees were making the most of them, circling as they searched for the best landing spots.


Bumblebee loading up on pollen

     In all the decades that the same area was covered with lawn grass, I’d never seen pollinators get any benefit from it. Those bumblebees reminded me of why I’d made the change. It wasn’t just for fun. I got a lot of enjoyment from picking out the new plants. Watching them grow, bloom, and fill in is going to be a pleasure. But the new beds are also designed to offer food and shelter for the bugs.


    When I started my garden in the 1980s, English-style perennial borders were all the rage. I was going to emulate Gertrude Jekyll and Vita Sackville-West with elegant perennial beds. 


Not my yard

To my disappointment, that was not to be. Even if I’d had the skills, we didn’t have the space or the unobstructed southern exposure for those long sunny borders. I spent the next 30 years learning about what to grow in part to full shade.

Shade has its rewards, such as this bloodroot in early spring

    This summer’s new beds represent a paradigm shift, as well as a new time of life. Since the seismic change in my gardening point of view induced by reading Doug Tallamy’s Bringing Nature Home, I’ve started seeing my garden as a community of plants and animals, not just my own personal play space and blank slate for design experiments.


    In 1985 I might have seen those bumblebees as stinging pests. Now they’re very welcome harbingers of a new era, with pollen and nectar for all.



 

Monday, July 3, 2017

Back from the edge

Did you know that the Kirtland’s warbler is now a candidate for de-listing as an endangered species because its population has recovered from 167 breeding pairs in 1974 to more than 2,000 today? The news of this conservation success came to me via Living Bird, the magazine of the Cornell Lab of Ornithology.

Singing male Kirtland's warbler--photo USFWS


    The story of this 15-gram bird and its restored summer habitat in northern Michigan is a heartening tale of good will and sound science producing results. It could also be read as a parable for our time.


    The Kirtland’s warbler can only build its nest on the ground beneath young jack pines (Pinus banksiana) no higher than around 12 feet. 


Ground-level warbler nest--photo USFWS

Fires caused by lightning or intentionally set by Native Americans used to result in a steady supply of young trees. Then in the twentieth century, settlers started suppressing wildfire, so the supply of young trees shrank.

    As you can imagine, nesting at ground level means the warblers lose a lot of their young to predators such as squirrels, chipmunks, snakes, feral cats and blue jays. They also can’t tell the difference between their own nestlings and young brown-headed cowbirds.


The cowbird is much bigger than a warbler--photo www.naturespicsonline.com

     The cowbird mother lays her eggs in other birds’ nests, tricking them into raising her young. Cowbird chicks are bigger than baby warblers and hog the food. Often the little warblers don’t survive. Cowbirds have spread from Midwest grasslands to places like the warblers’ home territory as humans have cleared land and built towns.


Cowbird egg in an Eastern Phoebe nest--photo Galawebdesign

    Heroic conservation efforts started in the 1950s and intensified when the Kirtland’s warbler became one of the first species protected under the Endangered Species Act. Federal and state biologists had to take drastic steps to restore the warblers’ habitat—controlled burns, then thousands of acres of jack pines cut and replanted. They also undertook a major program of trapping cowbirds, so that now few cowbird eggs are found in warbler nests. 


    So these are birds that need to build their nests and lay their eggs at the base of only one species of tree and that can’t tell their own babies from usurpers who scarf down all the insects they bring to feed their young. A set-up for evolutionary failure? At least we can say they were no match for the rapidly occurring changes in their surroundings caused by modern humans.


Human habitat, warbler desert--photo bpbailey


    What can we learn from this? I see two warnings. First, as climate change progresses, we’re going to need to adapt. Extraterrestrials observing us from another planet could draw an analogy between Americans and the warblers. The birds can’t live without jack pines; we seem to think we can’t live without a massive fossil fuel budget. If we can’t adjust to a new way of living, might we join the extinction wave? 



Can we find another way?

     Second, we’ve made radical changes in the natural world, just by expanding our population and taking over land for what we regard as normal, benign purposes. We’re going to need to find a way to make a smaller footprint.

   

Sunday, June 25, 2017

Planting party

What a week! On Wednesday, Kevin Newman’s team finished work on my yard. They left me with two new beds filled with beautiful black loam, ready to be planted. On Friday I set out on a shopping binge, and now I’m shuffling the plants around, designing the new plantings. Chances to plant a whole new area come along once in a decade. I’m having a blast! 



Trying out arrangements of new perennials for sun and part shade


    The first stage of the renovation started Monday morning, with the men rapidly scraping away the lawn around the deck. In a couple of hours, the grass was gone. Then they cut down five hemlocks at back corners of the lot (more on this in a future post), dragged the pieces out to the chipper parked in the driveway, and reduced them to wood chips. They returned the chips to the yard, using them to cover two new paths. 


Wood chip path for trundling wheelbarrows

Paths made from our own wood! You can’t get more sustainable than that! [note the presidential punctuation].

     The longest phase involved the heavy work of lifting large bluestone pavers from around the deck and putting in a new stone path leading toward the garden.

    What’s going into the new beds? They’re partly in sun, which means a chance to grow flowers that can’t thrive in most of the garden because it’s too shady. I had so many perennial darlings on my wish list that the problem was to pare it down. One of everything is not a good design principle. 


    I was looking for plants that stay low, so they won’t block the view of the garden from the deck. I thought back to a successful bed that designer Betsy Brown created for us in 1994 for a hot, dry west-facing spot. This time natives were a priority, but I couldn’t bear to leave out a few imports that had been stars of Betsy’s design.


Lady's mantle (Alchemilla mollis) had to be included--photo by Anneli Salo

    So far here are some high points of what I’ve chosen: For the sunniest area, Achillea ‘Coronation Gold,’ a yarrow with gray foliage and flat yellow flower heads in a subtle shade of yellow, 


'Coronation Gold'

an elegant St. John’s wort (Hypericum ‘Magic Universe’) with golden flowers, dark red fruits, and foliage with tones of red and blue, 

St. John's wort fighting off depression

prairie dropseed (Sporobolus heteroleptus), a native grass that will contribute panicles of pinkish-tan flowers in late summer, and a low-growing blue juniper (Juniperus squamata ‘Blue Star’) for winter interest.

     For the partly shaded section, a few I have high hopes for include the red-gold flowers of sneezeweed (Helenium ‘Short ‘n’ Sassy’), 


A similar sneezeweed--photo by Dietzel

a nice goldenrod (Solidago odora), and some blues in the form of Stokes aster (Stokesia laevis ‘Blue Danube’) and Canadian phlox (Phlox divaricata ‘Blue Moon’). Among these I have a chance to intersperse some of my favorite ground covers: bearberry (Arctostaphylos uva-ursi), wintergreen (Gaultheria procumbens), and a multi-colored bugleweed (Ajuga reptans ‘Burgundy Glow’).

Gaultheria procumbens does well in part shade

     This is just the first pass. Stay tuned for the editing process.