Picking a tree is a matchmaking game. Take some time to notice the trees in your neighborhood: how big are they? What do the leaves look like? What do I want to see out the front window each morning? What kind of foliage do I want to appreciate every time I come home from the grocery store? You can use apps like iTree or iNaturalist to identify local tree species by taking photos of their bark and leaves.
Sherwood Design Engineers sat down to review thousands of trees and are gathering a list of the best options for the Oakland EcoBlock. These species are well-suited for the neighborhood: they have relatively low water usage, low isoprene emissions (worsens local air quality), and high resiliency in a changing climate.
The team has broken down the decision into a few simple considerations:
What kind of foliage do you want to enjoy? You can look up the tree species to understand its seasonality and variation throughout the year. Be sure to chat with your neighbors to avoid placing a male and female tree next to each other, which would cause unwanted fruiting.
How does the light move throughout the day? Think about where the shade would fall—will it help shade pedestrians and cars, or help your household save energy in the summer? Consider where you might not want shade—what would be blocked by a big canopy? It is easy to underestimate how good trees are at growing, so be sure to match your long-term goals with fully developed tree growth.
LOW WATER DEMAND
We all know water conservation is critical. The last century has had as many drought years as wet years in the Bay Area. All the recommended trees do well in this climate, but some have particularly low water demands. Consider xeriscaping and grouping plants that have similar water demands so you can water areas on the same irrigation schedule.
Native species readily plug into the existing ecosystem and sustain a wide range of insects, birds, and animals. While it is impossible to exclude all non-native species—which provide ecological value—we should encourage a robust network of California natives to provide a stable ecosystem.
LARGE TREE WELL
Tree roots are incredibly important for the tree and soil. In urban spaces, we often give trees tiny, shoebox-sized areas to grow and they fight back, pushing up against the sidewalk and expanding beyond the soil that is provided. Imagine the tree flipped upside down–the root structure is up to 3x the expanse of the branches! If you want your tree to flourish, give it suitable room to grow big and strong.
Community engagement is critical to tree survival. In Oakland, 99 percent of trees planted by the City will die within ten years if they do not receive adequate follow-up care. Trees planted with community participation often avoid the top causes of tree death, which include a lack of water, physical harm, and dense soil compaction. Your plantings really rely on you and your neighbors to nurture them.
A lesson we can learn from trees–we all thrive together!
Cover image credit: Anna Haefele
Icon credit: Sherwood Design Engineers