While many of us dream of becoming one with the woods, most of us in the urban Midwest are only working with a few acres of backyard land. The forest ecosystem is incredibly diverse and complex, so how can we grow a forest in a modest backyard? By copying nature, that’s how. Here’s what you need to know to become a naturalist in your very own backyard.
Definition of a Tree
Let’s begin with the simple definition of a tree. Surprisingly, many people confuse this terminology and accidentally commingle it when referring to many species that are, in fact, shrubs. In general, a tree is a woody perennial that grows to approximately fourteen feet tall or more. We can also divide tree species down into further categories:
- Native trees are essentially naturally occurring, region-specific species. Often, their original occurrence (or naturalization) dates back almost 20,000 years ago through the migration of melting glacial ice sheets.
- Non-natives are trees that have been introduced to a region. However, their environmental requirements are well-adapted and considered ‘hardy’ to the region in which it was introduced, and therefore thrives even though it didn’t occur naturally.
- Conifers (cone-bearing trees), also commonly referred to as evergreens.
- Broadleaf trees (flowering trees), also commonly referred to as deciduous.
Mimic the Natural Forest Ecosystem
Mimicking the natural forest ecosystem is a lofty goal and one that cannot be perfectly or completely replicated (we’d be ignorant to think we could try). Essentially, nature knows best. A natural, undisturbed forest ecosystem consists of a diverse grouping of living flora, fauna, and abiotic elements such as water, soil, and air—all of which are interdependent. Let’s look at the basic layers of a forest stand to understand better how we can attempt to replicate this diverse ecosystem on a much smaller scale, albeit an imperfect one.
The main layers of a forest are:
- Canopy: This is the very top layer of the forest. While it can be sparse below, the crowns of the trees are wide, lush, and open to photosynthesis.
- Understory: This layer is composed of dense, young trees and vegetation that are competing for establishment. Many animals prefer this area as it is more protected from the elements and eyes of predators.
- Shrub layer: This area lies low beneath the canopy in a relatively shady and humid environment, where low-light plants and shrubs are often found.
- Forest floor: Just as it sounds, the forest floor is comprised of herbs, ferns, and emerging trees and plants. It is also a very complex micro-ecosystem of decaying forest matter, insects, and soil, all of which are interconnected and dependent on each other.
How can we attempt to mimic this forest diversity and grow our own forest? To keep it simple, we need to assemble our yards in a manner that copies the above-mentioned forest layers with a mixture of large canopy trees, understory, shrub, and forest floor layers. For simplicity, the remainder of this article will focus on the main deciduous and evergreen trees to grow in your Midwest landscape.
Once you have a combination of these trees established, you can begin creating the lower levels of your forest by planting shrubs and perennials—but it’s always easiest to start with the big task of tree planting and fill in the remainder afterward. No forest was created in a day, and it will take years to attempt to replicate and grow one in your yard. Before you begin tree planting, let’s look at the most popular trees for our Midwest landscape.
The Best Trees for Your Midwest Landscape
- Black Spruce (Picea mariana) may not be as popular as the blue spruce (Picea pungens); however, blue spruce has had a problem in our region with rust, a needle disease caused by fungi in the Chrysomyxa genus. Meanwhile, black spruce seems to be more resistant to this fungus while offering the same ‘Christmas tree’ silhouette that we all love.
- Norway Spruce (Picea abies), a local favorite for its slightly weeping, grandiose growth habit, is a large tree that can reach upwards of 60-70 feet in height. A smaller yard could only accommodate one of these beauties, but it’s worth compromising some space to allow for this majestic spruce.
- Eastern White Pine (Pinus strobus) is a stately soft pine that can reach up to 60-80 feet in height. Its soft, blue-green needles rustle in the wind and create a soothing aesthetic that every landscape should have.
- Maples hail from the genus Acer, with hundreds of varieties. Prized for their autumn colors, many Quad Cities landscapes look lovely with the addition of hard maples such as the sugar maple (Acer saccharum) or smaller, softer wood maples such as the Japanese bloodgood maple (Acer palmatum & dissectum) species.
- Oak (Genus Quercus) are prominent forest species to add stately elegance to any landscape. Most common to our region are the red oak (Quercus rubra), white oak (Quercus alba), and swamp oak (Quercus bicolor).
- Birches are very adaptable and tolerant of our Quad Cities environment. The most common birch (Betula sp.) in our region are white birch (Betula papyrifera) and river birch (Betula occidentalis).
- Smaller ornamentals such as serviceberry, crabapples, cherry, redbuds, and Japanese tree lilac are also great varieties to explore and help create the understory of your backyard forest.
While this is only a simplified overview of the elements of a forest, we hope this information has inspired you to begin to grow your own forest by planting a mixture of evergreen and deciduous tree species into your landscape. Come visit our garden center in the Quad Cities metro area for more information and planting tips!