How trees communicate in our woodland gardens: The Hidden Life of Trees

Do trees work together to help one another?

If you love trees – and I know every woodland gardener does – then you need to get The Hidden Life of TREES. (Amazon Link)

Peter Wohlleben’s 288-page, New York Times best seller will open up a new world for Woodland gardeners looking for answers about what is really going on in their backyards, local woodlots and ancient forests.

There is a reason this book has sold more than 2 million copies. Canadian publisher Greystone Books unleashed the book in its 8th printing on September, 2016 in the First English Language Edition, and has never looked back. (A fully illustrated coffee-table version is also available, see below.)

Not convinced about the importance of this book, consider that it has also been made into a movie. Check out this YouTube link for a taste of The Hidden Life of Trees movie version. (It will be available on AppleTV starting the month of October.)

It should come as no surprise to any of us that several backyard trees work together to create their own environment – from cooling our yards with shade to creating their own fertilization and micro environments at ground level.

Sit back and relax with a good coffee and The Hidden Life of Trees. The New York Times best seller is a must for Woodland gardeners.

What will come as a surprise to most of us, however, is the incredible goings on under our feet – from just a few inches beneath the soil to the depths many of our mighty tree roots reach. Beneath the soil there’s a communication highway where battles are waged, where life and death struggles play out through the seasons, and where families of trees come together through the “Mother Tree” and work together, sometimes over centuries, to survive, and ensure the health and prosperity of the woodland.

If you are looking to purchase the Hidden Life of Trees, or any other gardening book for that matter, be sure to check out the outstanding selection and prices at alibris books.

Armed with this knowledge, woodland gardeners can begin to make sense of so many questions about our gardens; its forest canopies, why a variety of tree is not flourishing and how we can help our woodland thrive.

(Dr. Nadina Galle has taken her inspiration from The Hidden Life of Trees and The Heartbeat of Trees and used it as a building block in her groundbreaking work to use smart technology to monitor the health of the urban forest. Read about her outstanding work here in my recent article The Internet of Nature.)

But this is not a how-to book. There are no pictures of trees. There are no outright tips for how to plant trees, where to plant them or when to plant them.

The Hidden Life of Trees: What They Feel, How They Communicate is a book that explores the often mysterious lives of individual trees, of forests, of trees left alone to fend for themselves in urban areas, on our streets and in our backyards. This is a book, written by a German forester, about how trees have communicated with one another over decades and even centuries, how they work together to save their own against disease, natural disasters, man’s destructive habits and the invaders we have brought that threaten the very existence of our native trees. Underlying it all, is the affect climate change is having and will continue to have on our woodlands, our urban forests and ancient rainforests.

“Life as a forester became exciting once again. Every day in the forest was a day of discovery. This led me to unusual ways of managing the forest. When you know that trees experience pain and have memories and that tree parents live together with their children, then you can no longer just chop them down and disrupt their lives with large machines.”

— Peter Wohlleben

Trees work

Will a single tree thrive in my yard?

The author makes it clear from the beginning that the lone tree in the middle of our front and back yards surrounded by grass that is so prevalent in many urban homes, is not an ideal situation for a tree’s prosperity.

“A tree is not a forest. On its own, a tree cannot establish a consistent local climate. It is at the mercy of wind and weather. But together, many trees create an ecosystem that moderates extremes of heat and cold, stores a great deal of water, and generates a great deal of humidity. And in this protected environment, trees can live to be very old. To get to this point, the community must remain intact no matter what. If every tree was looking out for only itself, then quite of few of them would never reach old age.”

The above quote may well explain why our urban trees rarely reach maturity, let alone old age. Where I live, this is clearly evident in local birch trees. In the heart or our urban communities these trees rarely survive into maturity. In the older, more rural areas where trees are less crowded and are given more room to grow, Birch trees seem to do much better. In my yard, I have planted three clumps quite close to one another and they seem extremely happy, possibly beginning to communicate with one another.

As trees struggle on their own, some would die opening up the forest floor to sunlight, the author explains. “The heat of summer would reach the forest floor and dry it out. Every tree would suffer.”

Do trees help one another survive?

If we conclude that every tree is valuable to the forest community and worth keeping around, it should come as no surprise that, as Wohlleben writes, “…even sick individuals are supported and nourished until they recover.”

He compares them to a herd of elephants. “like the herd, they, too look after their own, and they help their sick and weak back up onto their feet. They are even reluctant to abandon their own.”

If you have never thought about trees in this way, you may be shocked about how deep Wohlleben goes to explain just how extensively trees communicate through primarily – but not limited to – underground networks.

For the doubters, let me just say that his arguments and scientific data are hard to ignore.

Five key takeaways from this book

• Trees are much more complicated than most of us realize and their means of communication are complex and sophisticated.

• The importance of planting a grouping (possibly an island or a grove if possible) of the same variety of native trees is much more beneficial than planting individual specimens, especially if they are non-native trees.

• Recognizing that a tree’s needs must be met not just after initial planting but long into their growth cycle is important, and reducing physical barriers can be critically important.

• Single trees planted in our yards are more on their own than we might realize, and it matters that they cannot communicate easily with other trees. Best to take extra care of these lone trees.

• A woodland garden thrives not only because it is more natural than say a cottage garden, but because trees work together to create a positive environment that helps to guarantee success even when they are threatened.

Can trees communicate?

Consider that four decades ago, scientists noticed an interesting phenomenon on the African savannah.

They noted that giraffes feeding on acacia trees moved on quickly to other trees. The same scientists discovered that mere minutes after the giraffes began feeding on the trees, the acacias began pumping toxic substances into their leaves to ward off the large herbivores. The giraffes moved on, walked past a number of nearby acacias, before resuming their feeding on a group of trees about 100 yards away.

“The reason for this behavior is astonishing. The acacia trees that were being eaten gave off a warning gas that signaled to neighbouring trees of the same species that a crisis was at hand. Right away, all the forewarned trees also pumped toxins into their leaves to prepare themselves…. The giraffes were wise to this game and therefore moved farther away … to a part of the savannah where they could find trees that were oblivious to what was going on.”

The entire book is filled with fascinating stories about how trees’ self defences are used to ward off fungal diseases, beetle attacks and even how they deal with woodpeckers and other potentially destructive mammals that depend on trees for their own survival.

This is just an example of the many ways trees may communicate in a natural environment. The book goes on to explain a myriad of ways trees communicate, but in doing so, it also explores the many ways communication between trees is cut off leaving orphaned trees alone and fending for themselves.

Communication between trees growing in managed forests and in many of our urban parks is often restricted and underdeveloped for a variety of reasons explored in the book.

How are single trees like “street kids”?

But it’s the chapters on street kids that many gardeners and homeowners will likely focus on the most.

A drive down a suburban street or through a large city reveals just how many trees are left alone to fend for themselves.

In his book, Wohlleben describes these orphaned trees as “street kids.”

“Urban trees are the street kids of the forest. And some are growing in locations that make the name an even better fit – right on the street. The first few decades of their lives are similar to their colleagues in the park. They are pampered and primped. Sometimes they even have their own personal irrigation lines and customized watering schedules.”

The problem comes when these trees decide it’s time to go out and establish themselves. They quickly meet with hard, unlivable soil and even concrete walkways, roads that don’t allow any water to penetrate down into the hard soil compacted by machinery

“When trees are planted in these restrictive spaces, conflicts are inevitable….The culprit is sentenced to death.”

It is cut down and another planted in its place, but the new one is planted in a built-in root cage to restrict its roots from ever causing damage to the surrounding hardscaping.

Sound familiar?

What problems does a single tree face?

The difficulties “street kids” face does not end there. In large urban areas, where the lights never go out, these trees never get a chance to rest. They need a period of rest to thrive. Often, the concrete traps heat and even winters, another time for the tree to rest, are non-existant.

The sun, too, heats the concrete and black asphalt to the point of killing any living organism in the soil beneath it, depriving the “street kids” of water and nourishment.

In large urban areas these problems are obvious, but take a look around at your own trees and consider if they are facing some of these same problems.

Are the roots of the tree in your front yard growing under the road? Would additional watering help it survive hot, dry periods?

Is your favourite dogwood struggling because it is now in bright sunlight most of the day after a neighbour cut down a large maple exposing it to harsh sunlight? Maybe we need to add a large shade tree nearby to reduce the amount of sunlight hitting the dogwood.

Is your concrete driveway cutting off all water to your favourite roadside maple tree? Maybe it’s time to do what I did and replace the old asphalt or concrete with stone or permeable brick to allow water to seep down into the roots of the tree. Not only will it help the tree, it also reduced the amount of toxic runoff from your driveway into the sewer systems by keeping more water on your property.

As I said earlier: this is not a how-to book, but it certainly provides food for thought about how we can help our own little forest survive and thrive in our woodland garden.

About the Author: Peter Wohlleben spent over twenty years working for the forestry commission in Germany before leaving to put his ideas of ecology into practice. He now runs an environmentally-friendly woodland in Germany, where he is working for the return of primeval forests. He is the author of numerous books about the natural world including The Hidden Life of Trees, The Inner Lives of Animals, and The Secret Wisdom of Nature, which together make up his bestselling The Mysteries of Nature Series. He has also written numerous books for children including Can You Hear the Trees Talking? and Peter and the Tree Children.

If you like the Hidden Life of Trees, be sure to check out its sequel The Heartbeat of Trees recently published.