Summer has been long and hot, and for most of us, our time has been spent (very) close to home. Whether you’ve passed the time surrounded by towering Douglas Firs in Lake Oswego, admiring Japanese Maples in Portland, or looking off into the distance at a giant Oak in Happy Valley, trees in the landscape help create a sense of place. And when the temperature remains in the 90s well into September, trees also provide critical shade and somewhere to rest out of the sun. The benefits of trees to people and place really can’t be overstated and are certainly worth appreciating as we say goodbye to summer and head into the fall.
Everyone instinctively knows that the coolest place in your garden is under the largest tree, but the cooling benefits of trees go beyond simply blocking the sun’s rays. Neighborhoods and landscapes where trees are planted are measurably cooler than areas without trees—so much so, that temperature maps are an extremely accurate predictor of canopy cover in cities, and vice versa. When it comes to the cost of cooling your home in the summer, and even heating it in winter, the presence of trees can help reduce your utility bill and expenses.
DID YOU KNOW? Water movement through plants is actually a passive mechanism, controlled by the leaves at the very top of the canopy. Roots don’t actively suck up water in the soil, rather the whole plant acts like a straw, and water moves through the plant from the wettest part to the driest. That means water diffuses through the soil to the roots, into the truck, and then up to each leaf and out through tiny pores in the leaves called stomata. The openness of the stomata in the leaves dictates how much water a tree will move through its system. And when those stomata are open, the water escapes and evaporates into the surrounding air which reduces the temperature of the air nearby. This process is called transpiration, and is responsible not only for distributing water throughout the plant, but for significantly reducing the temperature of the air around trees.
Design & Aesthetics
Trees, whether evergreen or deciduous, help anchor the landscape. It might seem counterintuitive, but by bringing large plants into a small space, you can actually make it feel bigger. And in a larger space, the presence of height and structure helps the eye rest, allowing you to better appreciate the entire space. We are about to experience firsthand how well trees help us measure the passing of time. Autumn is right around the corner, which means brilliant displays of reds and yellows and leaves crunching underfoot (until the weekly maintenance crews arrive).
DID YOU KNOW? Leaves don’t actually “turn” red in the fall. The red, gold, and orange pigments in leaves are in the leaf all year round, masked by the overwhelming presence of electric-green chlorophyll. Chlorophyll is the most efficient molecule for turning sunlight into energy through photosynthesis, which is why the bulk of our landscape plants are green. Anyone with barberries or heuchera will know that plants do come in a range of colors, and in those cases, they are expressing very little chlorophyll and relying on secondary pigments. In autumn, deciduous trees and shrubs prepare for winter by going into dormancy, and one of the first steps is to dismantle their nutrient-rich chlorophyll molecules to store those building blocks for the following year. As chlorophyll breaks down, the underlying pigments, with their rich and brilliant tones of burgundy, crimson, and gold, are finally visible.
Every garden has space for another tree. Whether you need to hide an unwanted view, create a lovely new feature area, or just fill a vacant pot on your patio as summer annuals fade, there is a tree for you. And we’d love to help you find it!