bark mulch

What exactly is mulch?  Well nothing much relating to gardening falls under the heading of “exactly”, but in general mulch refers to a covering applied to the surface of the soil.  It might help to think of it as a blanket.  The blanket on my bed keeps me evenly warm throughout the night.  The key word here is not warm-it is evenly.  If I am hot and then cold and then hot again, I wake up.  If I am evenly comfortable, I sleep undisturbed. 


Bare soil, exposed to sun and air, looses its water via evaporation quickly.  A cover layer of mulch, which might be hardwood bark mulch, bark fines, or leaf mold slows the evaporation rate considerably. Mulch not only conserves existing water in the soil, it is easy to saturate with water-either from the sky, or the hose.  Water on hard dry soil can run off before it has a chance to be absorbed.  Peat moss mixed into soil aids in the retention of water, but as a mulch it has distinctive drawbacks.  A thoroughly dry layer of peat is an excellent moisture repellant.  The perennial bed pictured above will loose water at a fairly rapid rate on a really hot July day.  Once we add more plants to this bed, we will mulch it. 


 Mulch discourages weeds from sprouting and growing.  If weeds do sprout through the mulch, they are easier to pull from moist soil.  Mulch applied in a very thick layer can smother plants.  A thick layer of old newspapers decomposes slowly enough such that any plant underneath will perish.  This can be handy, if you are trying to convert a grassy area to a garden.  This method of preparing a bed for planting takes a lot less muscle than digging.  What it does require is patience-time.  It’s important to distinguish thick from solid.  A pile of matted down grass clippings is missing one important component essential to decomposition. Air.  Airless decomposition smells and looks bad. It feels like a cross between slime and sludge.   

A thick layer of mulch is not necessarily better.  2-3 inches is plenty. When that layer of mulch decomposes, add another layer. Mulch piled up much higher may seen like a good labor saving idea, but this can suffocate plants-and this includes trees. 

   This tree grew into, around and through a chain link fence.  It is thriving, despite this injury.  8 inches of mulch piled up around the trunk of this tree could do far more harm than what this fence has done.  Note that there is groundcover, and a light layer of leaves at the bottom.   


I have never been a fan of mulch rings around trees.  I like trees set in the lawn, or in a garden bed.  Mulch rings do discourage a person operating a lawnmower or weed whip from getting too close to, or injuring the bark of a tree, but it is much more utilitarian than it is beautiful. 


 This tree rises gracefully out of the lawn.  This has a much more natural, and park-like look.  The other landscape beds have a lot of bark visible.  Mulch is good for plants, but it is not a substitute for plants.  Granted plants need proper spacing from their neighbors in order to promote healthy growth, but bark mulch does not a garden make.    


 There are other materials that work as a mulch.  Gravel is one of my favorites.  Stone does decompose, but it decomposes imperceptibly.  The entire side and back yard at the shop is mulched in gravel.  Water drains through it.  The wheels of our carts run over it easily.  And it shades the ground from the drying eyes of the sun.  The willows on the back lot line are planted in what amounts to big and little rocks, mixed with sand.  The decomposed granite mulch helps to slow the evaporation of water from the gound long enough so the trees can get a drink. 


Seeds will germinate, and plants will grow when conditions are right for them.  The smallest bit of gravelly soil between the stones on this terrace provided the perfect conditions for a pansy seed to germinate.  A sunny spot to bloom, and cool moist soil for the roots-courtesy of the mulch provided by this stone terrace.

Leaf Magazine Spring Issue


Leaf cover

As my landscape superintendent was on holiday this past week, my time was largely devoted to my crew.  But I finally had the time to read through the second issue of Leaf Magazine.  This digital magazine is the brainchild of Susan Cohan (noted garden designer and author of the garden blog Miss Rumphius Rules) and Rochelle Greayer (garden designer, and author of  the garden blog Studio G).  The issue really is quite remarkable, and fresh.  142 pages worth, chock full of interesting topics, great writers and writing, and excellent photography.  My favorite article?  The Bark Garden, by Ken Druse.  The photographs by Clive Nichol  are breathtaking.  The article about flower markets around the world was so interesting.  I am not one bit surprised that they already have 80,000 subscribers.  But don’t take my word for it, look for your yourself.





I have been told that dirt is what gets picked up by a vacuum cleaner, and soil in a medium in which to grow plants.  Semantics aside, I prefer the word dirt.  What is under my fingernails, and inside my socks is dirt.  That dried material on the end of my spade or on my trowel is dirt.  What cakes the floormats in my truck is dirt. What the dogs track in-dirt.  What provides a home for my trees, shrubs, and perennials, and my container plants-dirt. 

Dirt is a big word.  Some dirt is cream white, and grainy-do not count on it to retain water.  Sand is a type of dirt whose particles do not stick together.  Water drains right through it. On the beach off Tybee Island near Savannah, Georgia-sand.  It drains and dries within seconds of its exposure to waves.  A sand beach on the ocean-one of life’s great pleasures. What grows there?  Tufts of grass.  Those tufts always look stressed, and tired, I might add.  Sand is a lean medium.    

Some dirt is an iridescent colored and greasy material that sticks to everything-shovels, hands-and roots that are gasping for a little air.  Clay is a very heavy water retentive dirt.  Once it dries out, it is hard-bone hard.  Terra cotta pots are made from clay dirt.  The word terra cotta, literally translated, means fired earth.  Very heavy clay dirt is loath to give up its water.  Farmers use clay to line the bottom of ponds built to provide water for livestock.  I have only built one pond that was lined in clay.  I had a client who was game.  12 inches of clay lined her pond.  Once all of the air was compacted out of it, the water level in the pond stayed fairly constant. The heavy clay soil pictured above-like the bottom of that pond.  

Both sand and clay-dead dirt.  I don’t mean this, really.  Both are composed of minerals-natural elements.  Silica, iron, manganese and the like. A ball of clay that I have squeezed all of the air out of-rock like. My clay rock is not so different than a granite rock,  in theory.  Granite is just harder than clay.  Formed clay, like granite, has been a building material for centuries.  Drain pipes, chimney flues and floor tiles-made of fired clay. Natural rock may be inert, but it is has a history that one could call a life.  Some geologists think that rock is a living organism.  This may be true in the abstract, but would you expect a columbine to take hold in a stack of quarry tile?  Not likely. 

Good dirt, the kind of dirt that encourages vigorous growth and health, is loaded with organic material.  What does this mean exactly?  Plants grow and prosper.  Once the seeding, fruiting and blooming is done, they die.  Even the biggest and the oldest trees enentually die. When living things die, they decompose.  They become compost.  Compost is the decomposing residue of the lives of many.  In undisturbed forests, lichens and moss colonize the surfaces of rocks.  Those colonies catch the debris from falling leaves-and trees.  This lean dirt, these natural and shallow pockets of decomposed plant material, provide a medium in which plants can take hold, and thrive. 

 Clay dirt, and sand dirt mixed together makes a leavened soil.  The sand particles help break up the clay.  This means water can be supplied to a plant, and then drain away before the roots rot.  But leavening is not enough.  Great dirt is loaded with organic material.  compost.  The remains of other plants.  Organic material further leavens dirt-dirt great for growing is loose, friable.  Air is a big part of the party.  Roots need air to survive, and thrive.  Who knows what other nutrients in decomposing plant material contribute to the next generation of plants. 

What else from that organic material?  There is plenty of controversy.  There are those who say compost feeds the soil.  There are those who say all compost does is promote an even absorption and slow release of water.  Water retention, if you will.  There are those that say organic material fuels the next generation of plants.  That organic material,  unsullied by any human intervention, makes for healthier, better lives.  Purely organic soil, organically grown plants-whenever I hear this, I swing back to some straight dirt talk.  Good dirt is essential to a garden.   

 good dirt

Great dirt is crumbly, friable.  It holds moisture to a point, then it drains.  A high compost content makes soil rich-I cannot really explain what I mean by rich, but I can smell it.  It has a certain feel.  It falls off  the spade and trowel. Great dirt running deep will endow your garden.  Dig a big scoop of your soil.  Pick up what your hand will hold.  If it sifts out between your fingers, add lots of clay, and lots of organic material.  If it sits in your hand like a heavy lump, add some sand, and lots of compost.  Aim to amend your soil. Your treasured plants need air, minerals, and compost. Thinking to plant a garden, or install a landscape?   Cook up some really good dirt.

good dirt

I could not cook a dinner for friends if my life depended upon it.  But I can make, or amend, or tweak dirt-cook dirt- such that plants grow.  I do what I can to provide good dirt for every plant on my property.  Could I teach a class in soil science-no. This is by no means a scientific discussion of soil. This is a fairy tale about good dirt.  A story-no more.  Take this story where you will. But I will say that the dirt under your nails will help your garden prosper. 


Sunday Opinion: Vernissage

Three years ago today, April 1, 2009,  I published my first post. To follow is a reprint of that post, entitled “Vernissage”.


Strictly speaking, the French word vernissage speaks to the opening of an art exhibition.  I learned the word recently from a client with whom I have a history spanning 25 years.  This speaks a lot to the value of nurturing long term commitments.  I have learned plenty from her, and from her garden, over the years. In the beginning, I planted flowers for her.  Our relationship developed such that I began to design, reshape, and replant her landscape.  She was passionately involved in every square foot of her 8 acre park.  Needless to say, the years flew by, one project to the next.  I have favorite projects.  A collection of fine white peony cultivars dating from the late 19th century was exciting to research and plant.  A grove of magnolia denudata came a few years later.  Another year we completely regraded all of the land devoted to lawn, and planted new.  I learned how to operate a bulldozer,  I so wanted to be an intimate part of the sculpting of the ground.  There were disasters to cope with, as in the loss of an enormous old American elm.  Deterring deer was nearly a full time job.  Spring would invariably bring or suggest something new.        

In a broader sense, vernissage refers to a beginning- any opening.  This has a decidedly fresh and spring ring to it.  I routinely expect the winter season to turn to spring,  as it always does.  But every spring opening has its distinctive features. Last year’s spring was notable for its icy debut. Grape hyacinths and daffodils ice coated and glittering and giant branches crashing to the ground.  This year, a different kind of drama altogether. My first sign of spring was the birds singing, early in the morning.  It was a bit of a shock, realizing how long it had been since I had heard the birds.  Why the break of my winter this year is about hearing the singing-who knows.  Maybe I am listening for the first time, or maybe I am hearing for the first time.  Every spring gives me the chance to experience the garden differently.  To add to, revise, or reinvent my relationship with nature.

Much of what I love about landscape design has to do with the notion of second chances. I have an idea.  I put it to paper.  I do the work of installing it.  Then I wait for an answer back.  It is my most important work-to be receptive to hearing what gets spoken back. The speeches come from everywhere-the design that could be better here and more finished there. The client, for whom something is not working well, chimes in.  The weather, the placement and planting final exam test my knowledge and skill.   The land whose form is beautiful but whose drainage is heinous teaches me a thing or two about good structure.  The singing comes from everywhere. I make changes, and then more changes.  I wait for this to grow in and that to mature.  I stake up the arborvitae hedge gone over with ice, and know it will be two years or more-the recovery.  I might take this out, or move it elsewhere.  That evolution seems to have a clearly defined beginnings, and no end.  

But no matter what the last season dished out, I get my spring.  I can compost my transgressions. The sun shines on the good things, and the not so good things, equally.  It is my choice to take my chances, renew.  The birds singing this first day of April means it is time to take stock.  Start new.

  I can clean up winter’s debris. My eye can be fresh, if I am of a mind to be fresh.  I can stake what the heavy snow crushed.  Spring can mean opening-the opening of the garden.  Later, I can celebrate the shade. I can sculpt ground. I can move all manner of soil, plant seeds, move, and renovate.  What I have learned can leaven the ground under my feet-if I let it.  Spring will scoop me up.  Does this not sound like a life? I can hear the birds now; louder.

Vernissage. Think of it.  Spring


The client I spoke of in this post April 1 of 2009 is moving to a new house, a much smaller property the end of this month.  Her passion for one garden is coming to a close.  A new garden is waiting.  No spring that came before will be quite like this one.Though I have published 987 essays in 3 years, the most important one is the next one.  And the next one after that.  Today also marks 20 years to the day that Rob and I began working together. There have been ups and downs, but the relationship endures, and evolves.  Suffice it to say that Detroit Garden Works is an invention that reflects that relationship.  Vernissage?  This 20th anniversary is most assuredly a spring moment.  The both of us, in concert, and individually,  have plans for the next twenty.  Yes we do.