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Sedums and Other Fall Flowers: GBBD, September 2016

September 16, 2016

September sedums-001Despite drought and some overnight temperatures in the thirties (F), there are still many flowers  blooming in my garden. The sedums, of course, are autumn stalwarts, generally unfazed by drought or cold.

I am pleased to see that the sedums have a lot of company in the mid-September garden. In recent years, I’ve been making an effort to choose plants that will extend my garden display into fall.

liatris scariosa flowersGiven this effort, it’s not surprising that the greatest variety of fall flowers can be found in my newest garden areas.  The recently planted Side Slope, for example, includes three varieties of Liatris with overlapping bloom times. The earliest of the three, Liatris spicata, finished blooming in August, but the blooms of Liatris aspera have moved from the top of their tall spikes in mid-August to the bottom in mid-September. And the fluffy button-like flowers of Liatris novae-angliae are now at their peak.

The most exuberant display of fall flowers can be found in the Porch Border by the front entrance to my house. porch border SeptemberAt first glance, the blooms of annual cosmos and cleome dominate, but a closer look reveals a number of other flowering plants. Heuchera x ‘Raspberry Regal,’ Tradescantia virginiana ‘Pink Chablis’ and Geranium x oxonianum have all been blooming continuously for more than three months. While the Heuchera and the Tradescantia are winding down, the Geranium is continuing to make new flower buds. It’s a mystery me why this hardy geranium, with its clear pink flowers and mounds of attractive green foliage that still look fresh in September, is not readily available from nurseries. It is an easy-care plant with no pest problems, it is easy to propagate (forming big clumps that are easy to divide and also self-sowing), and in cool climates, it has an exceptionally long bloom period.

cosmos September Geranium oxonianum flower

The tall garden phlox (Phlox paniculata), while not blooming as profusely as they were in August, are also still flowering in the Porch Border (and elsewhere in the garden).

September phlox-001

lavender walk SeptemberTurning the corner from the Porch Border, we come to the Lavender Walk, which is also doing surprisingly well in mid-September. Here the flowers of two different varieties of Lavendula augustifolia,  ‘Hidcote’ and ‘Munstead Strain’ are blooming with Echinacea purpurea ‘Magnus’ and Sedum x ‘Autumn Fire.’

echinacea & lavender sedum & lavender
These are only some of the delights in my September garden, and there are more still to come. In the Porch Border, for example, the flowers of New England aster (Symphyotrichum novae-angliae) ‘Alma Potschke’ are just beginning to open, and these plants are loaded with flower buds! alma potschke opening

This is also the time of year to enjoy the many varieties of aster and goldenrod that grow wild at the edges of my garden.

asters & solidago

Garden Bloggers’ Bloom Day is hosted on the 15th of each month by Carol at May Dreams Gardens. Visit her blog to see other gardeners’ September blooms.

To Dig or Not to Dig

September 10, 2016
side slope progressWhen I first began gardening, the gold standard for preparing new perennial beds was double digging. In The Garden Primer (Workman, 1988) – my gardening bible at the time – Barbara Damrosch described the process this way:

…I remove the soil from a section of the bed to the depth of a spade and set it aside. Then I loosen the soil under it with a digging fork, working organic matter, lime and whatever else the soil needs into the subsoil. I replace the topsoil layer, but only after I have added soil amendments to it as well. (p. 35)

For decades, I followed this practice, using double digging to amend my poor sandy soil and make it a welcoming home for plants.

More recently, however, double digging has come into disfavor. This topic came up early in my Master Gardener course. One classmate reported seeing bumper stickers in her affluent coastal town that read “Friends don’t let friends double dig.” The University of Maine scientist who taught our class on soils seemed mystified by this controversy. The university’s agricultural scientists warn against damaging soil structure through “recreational tilling,” but they consider tilling in soil amendments an important part of taking care of the soil.

Image result for soil texture triangle image

To understand my dilemma, you need to understand that my property sits on a big glacial sand deposit, and that my soil is what soil scientists call “loamy sand.” The diagram above shows different types of soil textures, depending on their mix of sand, clay and silt. As you can see, “loamy sand” is just one step up from pure beach sand (in the lower left corner of the triangle); it is a mixture of 70-85% sand with small amounts of clay and silt and has almost no organic matter. Not only are there relatively few plants that will grow happily in this loamy sand, but it is also very poor at retaining either moisture or organic matter. So if I want to garden here, the question is not whether to add organic matter to the soil, but how.

To decide whether or not to double dig my new flower beds, I needed to consider (1) alternative methods for adding organic matter to the soil and (2) the reasons why double digging has fallen into disfavor. Let’s start with the alternatives. One is to add organic matter on top of the existing soil and let it work down into the soil over time. This is the method I use to recharge organic matter in existing flower beds. But I didn’t consider this a workable alternative for my new garden areas; I’m in my late sixties and can’t afford to let years go by while I wait for organic matter to build up in the soil. Another alternative is the “lasagna” method, which involves covering the existing ground with cardboard or wet newspaper and then piling several inches of compost on top. The idea is that the cardboard or newspaper kills any sod or weeds while the organic matter improves the soil. I used a variation on this method to create the raised bed in my back garden, but I don’t want my front garden to consist of raised beds and it seemed as though I would have to pile the organic matter up quite high in order to put plants in right away (rather than waiting for the weeds to die, the cardboard or newspaper to decompose, and the organic matter to work its way down into the soil). A third alternative is tilling rather than digging, spreading several inches of organic matter on top of the soil and then turning it under gently with a garden fork.

To decide between tilling and double digging, I needed to look at the arguments against double digging. The main ones are  (a) that soil plays an important role in carbon sequestration so that digging releases carbon into the atmosphere and (b) that digging destroys soil structure. I quickly decided that carbon sequestration wasn’t really an issue in my case; it is the organic matter in soil that provides carbon, and the big problem with my soil is that it lacks organic matter. Soil structure, however, is a trickier issue. Soil structure refers to the way that particles of soil are arranged, particularly the ways that bacteria, fungi, and organisms like worms bind particles together into clumps or soil aggregates. In my earlier double-digging days, I would carefully break up clumps into friable crumbs of soil. Now I know better; soil aggregates are an important part of healthy soil structure, and disturbing the soil inevitably damages soil aggregates. Because my soil had already been disturbed by the construction process, however, there weren’t many soil aggregates to damage.

I decided that double digging is a reasonable way to add organic matter to this backfilled soil. Sure enough, as I have worked with the soil, I have encountered very few clumps. I dig out soil to the depth of my spade and pile it into my wheelbarrow, removing weeds and their associated roots as I go. I also remove any rocks or large stones, but I try to leave any clumps of soil undisturbed. Occasionally, I encounter a lump that may be a soil aggregate or may be a soil-covered rock. In the past, I would have squeezed it to find out, breaking apart the clumps of soil. Now, I tap these lumps gently against the side of my wheelbarrow. If they are rocks, they make a metallic “thunk” sound, but soil aggregates make a soft thud. When I put the soil back into the ground, compost and cow manure have been mixed in with the sand and loamy clumps.

As I worked to amend the soil on my back slope, I noticed a big difference in soil structure when I reached an area that had not been disturbed by the construction. Here my digging did disturb soil aggregates, and a different method for adding organic matter probably would have been preferable. This means that I will need to rethink how I add organic matter to my soil as I begin (next year) to work on sections of the front garden where the poor sandy soil was not disturbed during the construction of my house addition.

The Side Slope: Mission Accomplished

September 1, 2016

side slopeMy big garden project for this summer has been to turn the weedy slope that runs along the side of my driveway into a mixed planting of perennials and shrubs.

This is a large area (almost 450 square feet) and it consists mostly of backfilled soil from the construction of the retaining wall. Even before the soil was disturbed by construction, it was loamy sand with little organic matter (a soil test returned a value of .5%) and little ability to retain moisture. Before I could put in plants in this area, I needed to add organic matter, a time-consuming process. I added 1.5 cubic feet of compost and composted cow manure to each 6 cubic feet of soil, a process that took 45 – 90 minutes for each 6 square feet of soil surface.

side slope in progressI began working on this planting in early June, with a goal of finishing by the end of August. By late June, I had amended the soil in a 3-4 foot swath along the top of the slope and put in a row of plants. For the next two months, I continued to amend the soil in six-square-foot sections, first working my way down the wide end of the wedge-shaped slope, from top to bottom, then along the top of the remaining unworked area, then alternating vertical swaths from top to bottom with horizontal swaths from wide end to narrow end.

side slope shrinking wedge_1 By the beginning of August, as the remaining wedge left to be amended got smaller and smaller, I could see the end in sight and began to visit nurseries to buy plants.

I developed a planting design for the Side Slope during the winter and continued to refine it as I prepared the soil and began to install plants. I tied this garden area to the Back Slope that occupies the other side of the long stairway up from the driveway by repeating several of the plants that grow there. These include green hostas (probably H. ventricosa or H. fortunei), Siberian irises, tradescantia, balloon flowers, and daylilies. Below is the composition of the final Side Slope planting:

image

side slope upper plantingTwo weeks ago, I decided to take a break from preparing soil and spent three days putting in the remaining plants for the top half of the slope and also adding a row of stepping stones at the middle of the slope to provide access for maintenance.

A week later, I had finished preparing the last small wedge of soil at the bottom of the slope and was ready to add the rest of the plants. First I planted the last of the shrubs for this planting, a cotoneaster; then I began to spot the rest of the plants, adjusting their locations from the paper plan to the realities on the ground. While the plants on the upper slope were mostly bought new from nurseries, most of the plants on the lower part of the slope were divided from plants in my garden. (This means they will look droopy until their roots get established.)

side slope planted_1

With the Side Slope now planted, I have finished creating my Entry Garden, the plantings that guide a visitor up the stairs from the driveway to the entrance level of my house and then along the walkway to the front door. These plantings include three flower beds around the front door (the Blues Border, Porch Border, and Patio Border) that were created last year and the new Side Slope and the old Back Slope that flank the stairs up from the garden.

I’m giving myself a few days break from major garden projects. Then, next week, I will begin work on the Fragrant Garden at the front of the house outside my bedroom window.

Learning About Maine’s Native Plants

August 24, 2016

CMBG native plants classFor three days in mid-August, I drove out to the Coastal Maine Botanical Gardens each morning for a course called “Introduction to Maine’s Native Flora.” The course was part of my certificate program in Native Plants and Ecological Horticulture, and it was taught by Melissa Cullina, staff botanist and Director of Education for the garden. Like all classes at the Coastal Maine Botanical Gardens, this one combined lecture and hands-on exercises, time in the classroom and time in the field, and was deliberately kept small to facilitate interaction (there were about 15 of us).

This was a challenging course, with a lot of information to be mastered in just a few days. The goal was for us to be able to recognize and identify a wide range of native plants from a variety of habitats. We were introduced to between 50 and 100 native plants, and had to master 30 of them well enough to be able to look at a sample branch in a vase and identify the plant by botanical name (genus name and specific epithet) and botanical family. I have made it a practice to learn the botanical names of plants, but I hadn’t previously learned the family names, so that was a new challenge. On the morning of the first day, we were introduced to various characteristics that are used to identify plants: leaf arrangements and shape, shapes of flowers and inflorescences, types of hairs on stems or leaves. In the afternoon, we went out into the garden to look at plants (mostly trees and herbaceous perennials) and to practice using our newly-acquired vocabulary to describe them. On the second day, we added more plants to our repertoire, including ferns, and also learned how to use various kinds of identification keys. On the third day, we focused on shore and salt marsh plants.

CMBG goldenrodsIt’s been a long time since I tried to commit this much information to memory in such a short period of time, and I sometimes felt like my brain was about to explode. But the amount of learning was also exciting. I had always felt overwhelmed by trying to figure out the minute differences among the various types of goldenrod (Solidago) that grow on my property. By the end of the first day of this course, however, I could see the differences clearly and was able to identify four different species growing in and near my garden. (These are Solidago juncea, Solidago bicolor, Solidago canadensis, and Solidago rugosa. There may also be a fifth species, but I will need to get out my hand lens to look more carefully at the shape of the stem and whether/where it has hairs to be sure.) Learning to identify the goldenrods has given me confidence to tackle another confusing set of related plants in the Asteraceae family– all the different wild asters growing around my house.

Next month I’ll be able to build on my native plant knowledge as I go back to the Coastal Maine Botanical Gardens for two more courses, one on collecting and propagating seeds of Maine native plants and one on invasive plants in Maine.

The Season of Summer Phlox: GBBD, August 2016

August 16, 2016

phlox Bright EyesAugust is a month when the garden can begin to look tired and bedraggled. That is especially true this year, when our drought conditions mean that foliage that would normally be green is shriveled and browning, some plants are splayed open at the center (as though trying to get as much moisture as possible into their crowns), and many flowering perennials are blooming sparsely or not at all.

The daylily (Hemerocallis) season in my garden is mostly over. In the entry garden, ‘Mariska’ and ‘Vanessa Barth’ are coming to the end of their blooms.

Mariska last flower Vanessa Barth

autumn minaret flowersMany of my late-blooming varieties did not get enough moisture in July to make flowers. One exception is ‘Autumn Minaret;’ but even its delicate flowers are shorter, earlier, and less profuse than they would be in a more normal year.

Among the plants that are waiting in pots and bags to go into the new side slope garden, two late-blooming varieties of daylily, ‘Southport Delight’ and ‘Olin Criswell,’ are showing off their beautiful flowers.

Southport Delight Olin Criswell

David against fenceEven in a difficult year, the tall panicles of summer phlox (Phlox paniculata) can be counted on to make a beautiful display in the August garden. In the back garden, flowers are fading on the early-blooming variety ‘Blue Paradise,’ but ‘David’ is just beginning to bloom. It’s white flowers make a beautiful display against the fence. The real show, however, is in the entry garden, where three varieties of Phlox paniculata are blooming at the back of the Porch Border.

At one end of the border, Phlox paniculata ‘Bright Eyes’ is blooming with cleome by the front entry. Phlox Bright Eyes with cleome

In the center, the flowers of ‘Robert Poore’ are blooming with cosmos. I love the way the rich color of ‘Robert Poore’ pops against the white railing of the front deck.

phlox Robert Poore with cosmos phlox Robert Poore pop
Phlox Miss Pepper The far end of the border is anchored by the flowers of ‘Miss Pepper.’ Because my bedroom has a glass door leading out onto the deck, when I open my eyes on these August mornings, I am greeted by this colorful display of phlox, cleome, and cosmos.

The best-looking part of my garden right now may be the Lavender Walk, featuring plants which are happy in relatively dry conditions. The lavender plants have put up a second flush of flowers. On one side of the walkway, their flowers mingle with those of Echinacea purpurea ‘Magnus.’ On the other side of the walkway, there are still a few flowers of ice plant (Delosperma) ‘Table Mountain’ blooming amid the lavender, and sedum ‘Autumn Fire’ is full of buds promising more blooms for September.

Table Mountain flower Autumn fire buds

Garden Bloggers’ Bloom Day is a celebration of flowers hosted on the 15th of each month by Carol at May Dreams Gardens. Visit her blog to join the celebration or to see what other gardeners have blooming this month.

Cherry Tree Under Stress: Tree Following, August 2016

August 12, 2016

cherry under stressMy part of Maine is officially in a “moderate drought;” it has been many weeks since we had any significant (1” or more) rainfall. I imagine that some of my garden blogging friends in the west would scoff at the idea of this as a drought, but I garden in what  is normally a water-rich region of the country. The biggest employer in my small, rural town is in the business of extracting and bottling our local water for export (Poland Spring water).

We had several weeks of dry weather last year, too, but it followed a winter with record-breaking snowfall amounts. When we got very little snow this winter, no one complained; we felt we deserved an easy winter after last year. But then a winter of low precipitation was followed by a warm dry spring, which was in turn followed by this warm dry summer. The river near my house is running lower than I ever remember seeing it before, and many people’s wells have begun to run dry.

So how is my little cherry tree (Prunus pensylvanica) faring in these stressful conditions? Although two young forsythia transplants nearby are looking sadly wilted, the cherry is standing up tall, and its leaves do not look desiccated. A closer look does reveal a number of leaves that are turning brown and falling, a sign of a tree protecting itself by going into dormancy. I also note that, although I saw two clusters of blossoms on this tree in June, no fruit ever developed.

cherry tree leaves

All-in-all, though, I am pleased with how my little tree is doing. This native cherry tree seems better equipped to handle moderate drought conditions than do my non-native forsythias. Its response of cutting off water and nutrients to a small proportion of leaves seems similar to what I’m seeing in mature oak trees growing nearby.

Happily, while I was writing this, a thunderstorm moved through, bringing heavy downpours and about .5” of rain in a few minutes. More showers are forecast during the next several days. I am hoping that this is the beginning of a new weather pattern and that my thirsty plants will finally get some of the water they need to thrive.

Tree following is hosted by Pat English at The Squirrelbasket. Visit her blog to learn about the trees other bloggers are following.

The Entrance Garden: Lessons from the First Year

August 2, 2016

entrance garden annualsAs I continue to slog away on year two of my front garden project, I thought it would be a good time to look at the results of year one’s efforts, particularly the two flower beds that flank the walkway from the front entrance of my house to the patio.

I wanted these flower beds to provide some privacy and sense of enclosure as people approached the front entrance so, especially along the front of the porch and deck (on the right side of the walkway), I included fairly tall varieties of garden phlox (Phlox paniculata), New England asters (Symphyotrichum novi-angliae ‘Alma Potschke’) and astilbe (Astilbe x thumbergii ‘Moerheim’s Glory’). At the front, the walkway is bordered by lower-growing plants of Heuchera ‘Raspberry Regal,’ Geranium x oxonianum, and Tradescantia virginiana ‘Pink Chablis.’ Daylilies (Hemerocallis) are grouped between the taller plantings at the back and the shorter ones at the front.

You can’t really see any of those plants, can you? That’s because I decided that my first-year planting needed some annuals to fill in the space until the perennial plants bulked up to their mature size. I bought a six-pack each of cleome and cosmos and divided them between the flower beds on the two sides of the walkway. There were two things that I didn’t anticipate when I made this decision:

  1. Especially on the porch side of the walkway, the perennial plants grew much larger in one year than I expected. The three phlox, two astilbes and two asters at the back of the border are already big mature-looking plants. At the front of the border, each of the four small pieces of a single heuchera that I divided grew larger than the original plant had ever been and bloomed much more profusely.
  2. I had never grown either cleome or cosmos before, just admired them from a distance (for example, while driving by) in other people’s gardens. I didn’t appreciate just how big those tiny seedlings I tucked in between the perennials in late May would grow by July! They are both taller and much bigger in diameter than I ever imagined they would become.  I wanted these plantings to provide a sense of enclosure at the entrance to the house, but I didn’t want people to feel as though they had to walk through narrow tunnel in order to get to the patio! Moreover, they have completely stolen the show from the intended stars. As the photo below taken from the back side of the patio border (on the left side of walkway) shows, the annuals are hiding the daylily blooms that are supposed to be the featured plants at this time of year.

entrance garden daylilies obscured

Another problem with the planting in the first year has been the extent to which plants impinge on what is already a narrow walkway. As soon as they bloomed, the tall spikes of the heuchera began to flop over onto the walkway. The cosmos have also tended to lean into the walkway, and the geranium plants have crept outward.

Fortunately, all of these problems can be fairly easily corrected, and I have learned a lot from the process. Here are the lessons I’ve taken away from these too-exuberant plantings:

  • Plants growing in my newly prepared flower beds grow quickly. I don’t need annuals to fill in while they mature.
  • I would love to grow some annuals (cosmos, cleome, some zinnias) in my garden, but this is not the place for them. I will not replant these here, but I will consider how they might be incorporated in the more informal plantings of the lower garden when I get to it.
  • I need to keep plants from flopping onto the walkway. Next year, I will make a discrete ‘fence’ of linking stakes to keep the flowers of geranium, tradescantia and heuchera up off the walkway.

I have enjoyed my new entrance garden this year, but I look forward to enjoying it even more next year without cosmos and cleome, when it will be more the garden I envisioned when I designed it.