You are here: Home / Archives for Woody Plants

Kousa Dogwoods


Cornus kousa, or kousa dogwood, has an impressive list of outstanding characteristics.  Since few properties are large enough for an arboretum, choices have to be made. Trees with year round interest draw my attention.  The kousa dogwood has outstanding exfoliating bark when it is of sufficient age.  Like the sycamore or London plane, a old kousa dogwood will randomly shed bark, revealing new bark of a paler color, from underneath.  As a result, an old trunk is multi-colored, and highly textural.  As much as I like bark, I like the kousa dogwood.  This tree furthermore sets brilliant red fruit in September.  That shiny fire engine red is my idea of fall fireworks.  


Notice I have made no mention of the beautiful white flowers that mature in my yard in June.  In a good year, those flowers may last 3 weeks; my gardening season lasts 7-8 months. I need more interest than what great flowers provide before I am moved to dig the the hole required to plant a tree.  Even my beloved magnolias whose bloom is so fleeting have great bark and branching, and large luscious leaves all season.  A long season of interest-I look for this. My Kousa dogwoods are next to invisible after they bloom.  You can only spot it in this picture, as the leaves are beginning to turn. 

Their green leaves fire up slowly, come the beginning of fall.  The contrast of that red, and that green is riveting.  The shape of the leaves and the pattern of the veins are never more showy than they are in September.  The changing of the guard from the summer foliage to the fall display is an event I follow closely.   

The late September Kousa color is peach; that peach will deepen and mature.  I do not know the science well enough to state the evolution of the color depends on night temperatures that are steadily dropping.  So many times I research my instincts about nature to find out my notions have no basis in fact.  Suffice it to say, the fall color on the kousa changes dramatically over the course of the fall.

I have four kousa dogwoods on the north side of my house.  All four have grown steadily over the past 15 years.  This kousa planted at the front corner of my Romeo and Juliet balcony has grown such that the branches have come up and over the deck; they are at my eye level now.  One branch of that dogwood grows over the driveway far below.  I never notice that branch until the fall colors up the leaves. The garage lights make those leaves glow an orangy red. 

The vibrant red kousa leaves, underpainted and glowing from inside with that early orangy peach color, are the star of my north side garden show for weeks. The fall is all about the evolution of the leaves.  How they grow and photosynthesize over the summer, then turn, how they fade-how they drop-a gorgeous visual lesson in the process that is nature.  The process I am writing about takes the better part of 3 months.  That three month spectacular leaf turn and drop makes a kousa dogwood a tree I would not do without.
There comes that brief time when the red leaves of my dogwoods are just about as intense as the red fruit. That spectacular fall color is one of many reasons why a Kousa dogwood is worth any gardener’s consideration.  I have considered no end of plants for my own garden, and for the gardens of clients.  Decisions get made; trees get planted and take hold.  A good choice matters much. 

A tree is one of nature’s biggest plants.  I think about every tree I plant, and its location, long and hard-given the space it will occupy, and what conditions on the ground it will influence.  I additionally hope any tree I plant will outlive me. That given, I choose which tree for where with great care.  Today I am delighted to have a foursome of Kousa dogwoods thriving in my garden.  Their fall leaves in color delights me.  The summer season has no end of visual delight.  I have three other seasons besides the summer; I have interest in some off-season delight. 


That congested thicket of red-orange kousa leaves peak, thin, and fall.  Those last few dogwood leaves holding on today speak eloquently to the end of the season.  Consider cornus kousa for your garden.  Should you already have one, consider more.  The fall color-enjoy every bit of it.

Posted on: October 18, 2010 2 Comments
Filed Under: Woody Plants, Good Design, Garden Design, The Natural World Tagged With: ,

Evergreen, Ever Lovely

Being Labor Day weekend, I knew I could expect the weather to change. Sure enough, it was 51 degrees when I came to work this morning, and I hear I can expect 48 degrees overnight.  Our British born Christine who works weekends came in today in shorts-and a sweatshirt-grumbling about how “perishing cold” it was.  The onset of fall gets me to thinking about reworking the garden-so it might be better next season.  But fall also has a way of bringing the issue of planting evergreens to the fore-as we have a very long leafless winter season ahead. Norway spruce thrive in our climate; should you have the space, they are brave and comforting against the winter skies. 

There are many cultivars of thuja; they can be very effective in providing year round privacy. Thuja Smaragd, or Emerald Green arborvitae, takes up little space on the ground compared to the big growing pines. Thuja Nigra is bigger growing, but still fairly vertical.  I could not do without them in my small urban garden.  In this landscape, thuja Pyramidalis provides privacy on a grand scale.    

Taxus media “Moon” is an upright growing yew that rarely needs any side pruning.  Taxus media “Hicks” is the old standby for vertical yews, but they are much more open in growth.  Choosing the right cultivar of evergreen for your purpose is important.  The natural habit of a plant  is a vastly superior to that too heavily pruned look.     

I use Green Velvet boxood almost exclusively-as it keeps its color and performs well even when we have terrible winters. It tolerates shearing well.  Should I need boxwood that grows taller, or bigger than 3′ by 3′, Buxus microphylla var koreana is a good choice.  It is much more open growing than Green Velvet, but sometimes the eventual scale of a plant is the most important issue.  The foliage of Green Mountain boxwood is very close in appearance to Green Velvet, and matures at 4′ by 3′. Vardar Valley boxwood has a beautiful blue cast.  Faced down with Japanese painted ferns-really beautiful.  Boxwood is handy as a companion planting to deciduous shrubs. It helps to relieve that twiggy look, or that cut to the ground perennial garden look-in the winter.  
There are no end of interesting and visually arresting cultivars of dwarf evergreens. Though I am neither a connoisseur nor collector, I know a beautiful and well grown evergreen when I see one.  People who love dwarf conifers really really love them.  Designing a landscape for a collection is great fun.  For each specimen plant or plant grouping I may choose a companion evergreen that will showcase that specimen.  The juniper “Calgary Carpet” is a juniper I can take to.  This prostrate evergreen has needles with a silvery sheen that is very attractive.      

Given my druthers, I would only plant blue needled evergreens far in the distance.  Everything at a great distance in a landscape has that far away blue cast.  The color blue seems so natural-far off. But creating an informal tapestry of various shades of green  can be very appealing.   

This old dwarf scotch pine on standard rules this view-never mind a climbing hydrangea  that has been draped over this wall for decades. All of the attending horizontal elements make much of the singular shape of this specimen evergreen. 


The most commonly planted evergreens in my area represent but a fraction of what is available to plant. In the above photograph, Pinus Flexilis “Vanderwolf’s” on the left, and Pinus Heldreichii Leucodermis further down the drive.  One of the nurseries where I buy plants lists 42 cultivars of Chamaecyparis alone. This is more than enough to replace one’s regret at the passing of the summer with an interest in making some new friends.

Posted on: September 4, 2010 4 Comments
Filed Under: Woody Plants, Landscape Design Tagged With: ,

Small Spaces

 

The dowager queen French vase from yesterday’s post has a home waiting for her-but not the home I expected.  An object of this size would need an even bigger space, wouldn’t you think?  What evolved was anything but.    

My clients bought a house that had never really been finished.  The landscape was much the same; unfinished.  My client referred to the property on the side of the house as “the music room mulch garden”.  It was bleak.  This very small space functioned as a transition space between the front of the property, and the rear-a sheer 8′ foot drop in grade. A boulder retaining wall at grade barely visible in this picture was punctuated by a staircase down with 16 stone steps-maybe more.  This left the area with an edge that was in fact a precipice.  At the base of the precipice, multiple air conditioning units, and a collection of meters apparent in this picture.     

My first design, they flat out rejected; I had missed some important information. My first design did not take into account that they spent their summers at a home on the East Coast.  OK, my plan for a cutting garden and whatever went with that was way off the mark.  Plan 2-a landscape that would function and look beautiful early and late, and especially over the winter.  A small landscaped area that would have big impact. A healthy hedge of Thuja Nigra sporting one lone out of place Thuja Pyramidalis was a starting point.  

Three linden espaliers of great age would form a backdrop to this small garden.  The green wall they would provide would take up little space, and would screen the clunky boulders and grade changes from view.  Enclosing a small space makes for a feeling of intimacy.  And the room would need some furnishing.  

Three linden espaliers, each about 10 feet wide, completely covered the back.  It would be up to my client to decide whether to maintain the horizontal pattern of the branches, or let the the twiggy growth make a solid wall of leaves. Green velvet boxwood organizes the ground plane.  The precipitous drop to the rear yard is shielded from view by a hedge of Thuja Nigra that matched the hedge already in place on the street side.  Flat and safe spaces are friendly to people. As for the mulch pile we had scraped up-that would be used to mulch the new plantings.  

Decomposed granite walkways make it easy to navigate the space. The color is easy on the eye, but provides strong contrast to the green elements.  There is no reason a small space cannot be a lively and interesting space.

A simple arrangement of plant material and gravel finishes the landscaping portion of the project.  Now what? 

From inside the house, a generously proportioned bench makes the space look inviting. The placement of the bench implies there will be something of interest to see.  I thought that old French vase might be just the thing.  

The colors of each compliment one another. The placement of a large element in a small space can be dramatic.


The view from the bench side is in scale with the size of the house.   Should I plant very tall? Short and wide? With what? It will take some time and thought to get the planting just right.

Posted on: September 4, 2010 1 Comment
Filed Under: Garden Ornament, Woody Plants Tagged With: , , ,

Some Thoughts on Spacing

Once there is a landscape plan in place, there is the matter of the plant count.  Determining a plant count has much to do with spacing.  I have read much about rules for spacing plants properly for optimal growth, but the issue is more complex than that.  For instance, if I am planting pachysandra, and space them at a foot apart, I need one plant per square foot.  For 500 square feet, I will need 500 plants, or about 10 48 count flats.  If I space them at 6″ apart, I need 4 plants per square foot, or 2000 plants, or about 40 48 count flats.  Option A asks for a modest up front investment, but I see a lot of time ahead devoted to weeding, the purchase and spreading of a lot of mulch, and a lot of water thrown on bare ground.  I also see a grim looking space for probably 3 years.  My solution?  Start a groundcover bed small and plant densely.   Enlarge it next year, or the following season- only that number of square feet you can plant densely.  My mature, healthy beds of pachysandra-individual plants are much less than an inch apart.

Spacing evergreens has everything to do with the desired outcome.  Should I plant a taxus densiformis in the middle of the lawn, and give it 50 years to grow, I will have a single plant of considerable size.  A hedge, or a mass of yews is more about a community. Sometimes I look at the distance between the rootballs.  The big idea here-everybody has their own subterranean digs. This may mean that the foliage touches.   

Plants are much more sociable than I.  I want my space. I was never so conscious of the need for my own space than after my knee replacement.  I was less than stable on my feet, and was not interested in an enthusiastic Golden Retriever broaching my borders. But plenty of plants do well planted in close quarters.  They are completely happy to relinquish their individuality, and become a part of a larger community.

One of my most favorite landscape moments-the arrival of the plants.  These 1.5″ caliper fastigiate hornbeams in 25 gallon pots would be planted as if they were the poles of a pergola. Carpinus betulus “Frans Fontaine” is a culitvar of fastigiate hornbeam which is slower and more densely growing than the species.  Even so, it will grow 30′-35′ tall, and 15′-18′ wide. I spaced them at 8′ on center, knowing they would grow together.  Someday there would be a green roof under which there would be shade.   

I had other reasons which influenced my spacing.  The house next door loomed over this side yard property.  Evergreens would have provided year round screening, but they occupy a lot of space at the ground plane.  My clients wanted to entertain in this space.  Given enough time, and spaced close together, they would eliminate this view of the neighbor.   

Carpinus are also very tolerant of pruning.  Decisions about spacing are specific to the species in question.  The vast majority of green spaces have not been planted by a person.  There are those wild places densely populated by plants.  No natural forest or meadow is at equilibrium; some plants are coming on as others are in eclipse.  Perhaps a lighting strike will “prune” a giant tree such that new plants can take hold around it.  Should you be interested in the exceptions to any gardening rule, visit any wild and untended space. 

Five years later, the new yews have grown together to make a mass.  The topmost row of yews had been transplanted from the front of the house; the new yews will eventually cover their bare lower limbs.  It sometimes makes more sense to underplant an old and ungainly shrub rather than tear it out.  These big old yews will eventually become part of a simple mass.Eight years later, the house next door has all but disappeared. As the carpinus grow taller, they can be selectively pruned on the underside to permit easy passage beneath them. 


The yews planted behind the carpinus are planted on a gentle slope that rises to the neighboring driveway. Though the shade has become considerable, they are green and well needled from top to bottom.  Allowing those densiformis yews to keep their natural shape is in large part responsible for their continuing health.  Yews do not respond so well to hard formal pruning.  Once all light is blocked to the interior of the shrub by a proliferation of growth on the exterior, those inner branches will go bare.  I have begun planting Taxus media Moonii in place of Hicks yews, as their natural growth is much more upright and formal. 


This is a great spot to sit.

Posted on: August 31, 2010 6 Comments
Filed Under: Woody Plants, Garden Design, Landscape Design Tagged With: , ,