By Tom O’Sullivan, gardener and horticulturist, VSB
Working as a horticulturist for several decades has allowed me to experience nature more than most. Small details will always amaze, such as the little white flowers from snowdrops appearing above the cold ground as early as January, or huge clusters of little red berries hanging from a mountain ash in the fall.
Nature is full of little secrets, and I enjoy sharing these experiences with others.
In my role as a gardener with the Vancouver School Board (VSB), I have many pleasant exchanges with community members. It’s common for a student, parent, teacher, or passerby to stop and remark on some aspect of the garden as I work. The most common reaction from elementary students when I’m pruning a tree is, “Stop, stop, you’re killing the tree,” to which I assure them, “No, no, I’m just giving it a haircut.” But this shows that they care.
Their curiosity is amazing, and there’s so much for them to discover. Quite often, while working on a school garden, an audience of young faces will appear to watch me turn the soil, clean up shrub borders, and tend to the plants.
They see a chaotic bed cluttered with dead leaves, broken branches, weeds, or gangly off-shoots look refreshed and beautiful. For them, seeing is believing.
Now that it’s late fall, and while bracing for the onslaught of winter, it’s tempting to believe there’s not much of interest in the garden. But when that perfect fall day bursting with sunshine and freshness appears from nowhere, opportunities for outdoor activities for students should not be missed.
These types of fall days are perfect for getting out of the classroom and exploring the anatomy of trees, and there’s no place better than your own school grounds to explore. The trees you walk past every day are fascinating to study.
In the simplest terms, trees consist of leaves, branches, trunks, and roots. The leaves conduct the magic of photosynthesis, sequestrating carbon from the atmosphere to form wood in the body of the tree. But wood is extremely heavy, just try standing a small log upright. Easy? No!
Here is some information about trees that teachers can use to help their students learn about and connect with the trees and nature that exists around their school:
Shape and form
Stand well back and see, from a distance, the size, shape, and form of a tree of interest. Look at its height, the network of branches, and where it’s positioned in the school garden
As you walk closer to the tree, make a note of where the outer edges of the canopy end; this is called the drip line. When deciduous trees are in leaf it’s very defined, but evergreen trees can demonstrate this characteristic anytime.
As it is fall season, most deciduous trees will have shed or are in the process of shedding their leaves. But different species of trees shed their leaves at different times. Usually ash is the first to drop its leaves, sometimes starting as early as the end of September. However, the leaves of beech or oak (now dry and brown) can remain attached to the tree well into the winter months. This ensures that leaves cascade onto the ground over a long period of time
Looking up at the branches, note the various sizes and shapes of branches from large boughs down to very small twigs. Note the differences between branch networks from deciduous and coniferous trees.
Trees generally have one central trunk or may have multiple stems. Tree trunks grow bigger and stronger every year. In their natural woodland settings, trees compete for light and, as they grow taller to catch the sunlight, the lower branches become less efficient, so they transfer their nutrients to the rest of the tree, die off, and eventually drop from the tree. In urban areas and parks, skilled horticulturists and arborists remove these branches in order to give the tree a more pleasant appearance. Look for calluses on the trunk where branch wounds have healed over.
This is the point where the main trunk meets the ground. In mature trees, huge anchor roots can be seen partially exposed above the ground at the very base of the tree.
This is the tricky part as, of course, we can’t see the roots below the ground. However, without knowledge of the root system how can we know about the life of a tree? It’s the root network that can be the most fascinating part of a tree’s structure. As a general rule, a tree’s root network can extend up to 50% farther than its height. That means a 20-foot tree will have roots that spread 30 feet under the ground in all directions. For scale, just ask a student to lie down on the ground and mark out their height while adding 50%. The roots at the very base of the tree are responsible for anchoring the tree to the ground, while farther away, beyond the drip line, the smaller roots, which are called feeder roots, send back water and nutrients.
In the fall/winter months, deciduous trees stand tall and proud like sculptures. Their magnificent form can be admired from the very top right down to the base of their trunks. While they might be sleeping for the winter, they carry vast stores of food that will see them burst into leaf in the spring and start their new season of making our schools and neighbourhoods full of vitality.
The next time you walk by that tree on your school ground, take a moment to appreciate its beauty and purpose. Trees may be quiet, but each one has a wonderful story to tell.