The Ultimate Guide to Turning Your Turf Lawn into a Native Plant Forest
A forest isn’t just a collection of trees; it's a dynamic, living web where trees, plants, animals, fungi, microorganisms, and humans coexist with nonliving elements like soil, water, air, and landforms.
Together, these components form an intricate ecosystem, constantly interacting to support and sustain life. By understanding how these processes work, we can recreate them on a smaller scale in our urban and suburban yards, building self-sustaining, flourishing ecosystems that produce food and provide habitat for wildlife.
Our mission is to create native plant landscapes in urban areas that are not only edible and productive but also extremely livable—spaces that feel natural, abundant, and comfortable.
In this guide, we’ll explore how a forest functions, what an established Oregon native forest looks like, and how we can recreate these regenerative systems in city landscapes.
We’ll dive into the components of a thriving forest and show how the right native plants can come together to create comfortable, beautiful, and livable yards—spaces that require little effort to maintain but bring lasting joy and harmony to those who spend time in them.
The Forest as a System
These interactions drive the flow of essential resources—energy, water, carbon, air, and nutrients—throughout the ecosystem, sustaining life in intricate food chains and webs.
To replicate these systems on a smaller scale, it’s crucial to first understand how they function and the roles each component plays.
At the core of every healthy ecosystem is the food system, which is made up of three key categories: producers, consumers, and decomposers. Each group plays an indispensable role in the movement and cycling of nutrients, ensuring the ecosystem remains balanced and self-sustaining.
Producers
Producers are organisms like plants, algae, and some bacteria that can produce their own food through photosynthesis, a fundamental process that powers nearly all life on Earth.
During photosynthesis, producers convert sunlight, carbon dioxide (CO₂), and water into glucose (sugar) and oxygen. The glucose provides the energy needed for growth and reproduction, while the oxygen is released into the atmosphere as a byproduct. This process fuels the producers and forms the foundation of the entire food chain by providing energy to herbivores and, subsequently, carnivores.
In a forest ecosystem, the young native trees, shrubs, and grasses are the primary producers. These plants play a crucial role in supporting life on multiple levels. They serve as food for herbivores, provide habitat and shelter for wildlife, and help maintain a stable climate by regulating atmospheric carbon dioxide levels. As plants absorb CO₂ from the air and convert it into glucose, they also release oxygen, which is vital for life on Earth. Over time, as plants mature, they contribute to the formation of humus (rich, organic soil), supporting further plant growth.
To recreate this process in your own yard, the first step is to introduce a diverse range of native plants that are adapted to your local climate and soil. Native trees, such as oaks, maples, and pines, are excellent producers that can anchor the system, while shrubs like elderberry and grasses like blue wildrye provide energy at various levels.
By planting a mix of perennials and annuals, you create a self-sustaining system that mimics the natural processes of a forest or meadow. These plants will absorb sunlight, CO₂, and water to fuel the cycle, creating a food-rich, oxygen-producing ecosystem in your own yard.
Urban Rewilding can help you kickstart your rewilding journey with expert native plant design, installation, and ongoing maintenance. Book a rewilding site visit, and we'll assess your landscape, analyze microclimates, and understand your intended use of the space. From there, we'll connect you with the perfect plants tailored to your yard’s unique conditions, helping you create a vibrant, sustainable, low-maintenance ecosystem.
Consumers
Consumers rely on other organisms for their energy and nutrients, as they cannot produce their own food through photosynthesis. Consumers are an essential part of the ecosystem because they help regulate populations of producers and other consumers, ensuring balance within the food web.
There are several categories of consumers based on what they eat, and each group plays a vital role in maintaining a healthy, functioning ecosystem.
Herbivores are consumers that feed directly on producers (plants). They include animals like rabbits, deer, and insects that graze on grasses, leaves, and other plant materials. Herbivores are the primary consumers in the food chain, and they convert the stored energy in plants into the energy they need to survive and grow. As they feed, they help keep plant populations in check, preventing overgrowth and promoting plant diversity.
Carnivores are consumers that eat other animals. They can be further classified into primary and secondary carnivores. Primary carnivores, like foxes and hawks, hunt herbivores, while secondary carnivores, such as wolves and larger predatory birds, prey on other carnivores. Carnivores play an important role in controlling the herbivore and other smaller carnivore populations, preventing overgrazing, and ensuring the continued health of plant populations.
Omnivores are consumers that eat both plants and animals. Examples of omnivores include raccoons, humans, and bears. They contribute to ecosystem balance by consuming a wide range of organisms and help maintain diversity within the food web.
To recreate a balanced ecosystem in your own yard, it’s important to support consumers at all levels of the food chain. Start by introducing a variety of plants to provide food for herbivores and include natural habitats for wildlife such as birds, insects, and small mammals. Incorporating native species that attract beneficial pollinators, such as bees and butterflies, will also encourage herbivores and pollinators.
By supporting a healthy population of predators and decomposers, you create a food web where each organism has a role and contributes to the overall health and sustainability of the system.
You can further enhance this process by providing animal water sources, dense plant cover for shelter, and avoiding using chemicals that could harm these organisms. By fostering biodiversity in your landscape, you create a yard that is not only full of life but also capable of sustaining itself for years to come.
Decomposers
Decomposers are organisms that break down dead organic matter into simpler substances, such as fallen leaves, dead animals, and decaying plants. This group includes fungi, bacteria, and detritivores like worms and beetles.
Decomposers release nutrients such as nitrogen, phosphorus, and carbon into the soil by breaking down dead material. Plants then take up these nutrients, enabling the life cycle to continue.
Decomposers are essential in nutrient cycling, enriching the soil, helping sustain plant life, and supporting consumers. Without decomposers, dead organic material would pile up, and ecosystem nutrient flow would be disrupted.
Wood chips in new forests support decomposers and enhance soil health. As the chips break down, they provide an ideal environment for mycelium, forming a nutrient-rich foundation. We then add rich soil, logs, and seeds, replicating the structure of a natural forest floor.
The Cycles of Life in a Forest
Forests thrive on four key natural cycles—oxygen, carbon, water, and nitrogen—and keep the continuous flow of essential elements coming.
The Oxygen Cycle: Plants absorb carbon dioxide and release oxygen through photosynthesis, providing the air we breathe. In turn, plants and animals respire oxygen and release carbon dioxide into the atmosphere.
In addition to producing oxygen, plants help filter pollution from the air, making urban environments healthier. Trees, shrubs, and groundcovers absorb harmful pollutants like carbon monoxide, nitrogen oxides, and particulate matter while also trapping dust and toxins on their leaves and bark.
A dense, diverse urban forest can reduce smog, lower temperatures, and improve overall air quality, creating cleaner, fresher air for communities. By integrating more native plant landscapes into cities, we can mimic the purifying power of natural forests, turning urban spaces into resilient, breathable environments that support both human and ecological health.
The Carbon Cycle: Trees act as carbon sinks, storing carbon absorbed from the atmosphere. When trees die and decompose or burn in a fire, this carbon is released back into the environment, continuing the cycle.
The Water Cycle: Water moves through the forest as precipitation, runoff, groundwater, and evaporation. Forests are critical in regulating water flow and maintaining clean water supplies.
In urban areas, the water cycle is disrupted by impervious surfaces like asphalt and concrete, which prevent water from naturally soaking into the ground.
By integrating native plants and forest-like ecosystems into urban landscapes, we can help restore the natural water cycle.
Plants absorb and filter rainwater, reducing stormwater runoff that can overwhelm drainage systems and pollute local waterways. Trees and vegetation help slow down water flow, and rainwater gardens can allow water to seep back into the ground, allowing it to seep into the ground and recharge groundwater supplies.
Additionally, plants release moisture back into the air through transpiration, contributing to cooling and increasing humidity in dry urban environments. This natural water management system creates cleaner water and helps reduce flooding, control erosion, and create more resilient urban ecosystems in the face of climate change.
The Nitrogen Cycle: Nitrogen is essential for plant growth and cycles between the soil, plants, and atmosphere. Decomposers, such as bacteria, break down organic matter to release nitrogen into forms that plants can absorb.
In a newly established forest or garden, we can help quickstart the nitrogen cycle by adding a thick layer of wood chips and a rich soil blend. The wood chips act as mulch, helping to retain moisture, regulate temperature, and provide a habitat for decomposers like fungi and bacteria that break down organic material. As these organisms work, they release nitrogen and other essential nutrients into the soil, giving the plants the best possible start.
Our soil blend is designed to be nutrient-dense, with organic matter that enhances soil structure and supports microbial life. This initial support helps the plants quickly establish strong root systems to begin cycling nutrients and going through the nitrogen cycle on their own. Over time, the ecosystem becomes more self-sustaining over time, with plants, soil organisms, and decomposers working together to cycle nutrients and naturally support healthy growth.
Layers of the Forest
When designing and installing a new urban forest, it’s important to consider the different layers of a natural forest. Each layer has a unique role in the ecosystem, and when we replicate these layers in an urban setting, we create a more resilient, self-sustaining environment.
The Canopy
The highest layer consists of mature trees whose leaves form a dense cover. This layer captures sunlight, enabling photosynthesis, and is home to species like eagles, bats, and insects.
Canopy trees can range from 80 to over 200 feet tall, and they come in a variety of shapes—some grow widely, while others have a more columnar form. When choosing the right canopy tree for your space, it's important to consider factors like height, spread, and overall shape to ensure it fits within the proportions of your yard and complements the surrounding landscape. The right tree can provide essential shade, habitat, and aesthetic beauty, all while supporting the broader ecosystem in your yard.
Some of the major trees that make up a Pacific Northwest Forest Canopy are:
Douglas-fir (Pseudotsuga menziesii): Provides habitat and food for wildlife, stabilizes soil, and improves air quality. Supports bark beetles, Douglas-fir tussock moths, and over 100 bird species like woodpeckers and nuthatches. Mammals include squirrels, deer, and black bears. Max Height: 200-300 feet.
Urban Planting Tips: It needs well-draining soil and plenty of space for its roots and canopy. Plant in parks or large open spaces, and avoid areas near power lines.
Oregon White Oak (Quercus garryana) supports diverse wildlife, improves soil with leaf litter, and provides shade. It hosts hundreds of insect species, such as moths and beetles, and mammals like woodpeckers, deer, and western gray squirrels rely on its acorns.
Max Height: 60-90 feet.
Urban Planting Tips: Prefers full sun and well-drained soils. Avoid overwatering. It is ideal for larger yards, parks, or naturalized areas.
Bigleaf Maple (Acer macrophyllum): Produces abundant leaf litter that enriches soil and provides shade and water retention. Supports pollinators like bees and butterflies. Seeds feed birds like grosbeaks and mammals like chipmunks.
Max Height: 50-100 feet.
Urban Planting Tips: Thrives in moist, well-draining soils and can tolerate some urban pollution.
Western Redcedar (Thuja plicata): Provides bird shelter and nesting sites, stabilizes soil, and regulates water flow. Supports cedar waxwings, owls, and deer species. Its foliage is a food source for moth larvae.
Max Height: 150-200 feet.
Urban Planting Tips: Plant in moist, shaded areas with good drainage. Avoid planting near concrete to prevent root damage.
Western Hemlock (Tsuga heterophylla): Creates dense canopy cover that moderates soil temperature, reduces erosion, and retains moisture. Its needles enrich the soil with acidic organic matter as they decompose. Supports caterpillars of various moth and butterfly species, bark beetles, and sap-feeding insects. Provides critical nesting and roosting habitat for owls, woodpeckers, chickadees, and kinglets.
Max Height: Up to 200 feet
Urban Planting Tips: Prefers partial to full shade, especially as a young tree, and moist, well-drained, acidic soil with decomposing wood. It thrives in cool, damp environments.
Urban Tree Planting Tip: Groves
Planting native trees in groves is beneficial because it mimics the natural structure and function of forests, creating a more resilient and self-sustaining ecosystem. In a natural forest, trees grow in communities where they support one another through interconnected root systems, shared mycorrhizal networks, and wind protection.
Planting trees in groves mimics natural forests by fostering ecological relationships that enhance soil health, regulate temperature, and provide habitat for wildlife. For example, a grove of bigleaf maples and doug firs will naturally enrich the soil with organic matter, create shade that benefits understory plants, and help the trees withstand storms, drought, and pests more effectively than lone trees.
By replicating these natural patterns in urban and restored landscapes, we create thriving ecosystems that require less maintenance and provide long-term benefits for people and wildlife. Native tree groves improve air and water quality, prevent soil erosion, and support pollinators, birds, and other wildlife, helping to rebuild the interconnected web of life that defines a healthy forest.
The Understory
The understory of a Pacific Northwest forest is the layer of smaller trees that grow beneath the canopy of Douglas fir, western red cedar, and hemlock. This layer consists of shade-tolerant species like vine maple, Pacific dogwood, and cascara, which thrive in the dappled light that filters through the upper branches.
These trees provide essential habitat for birds, insects, and small mammals, offering shelter and food through seeds, berries, and nectar. Many understory trees, such as vine maple, have multi-stemmed growth patterns that create dense thickets, offering protection for wildlife and adding to the structural diversity of the forest. Some of the major trees that make up the understory of an Oregon native plant forest are:
Pacific Dogwood (Cornus nuttallii): Provides food for pollinators, birds, and mammals; enhances soil health with its leaf litter. It supports butterflies, moths (like the spring azure), and birds such as robins and cedar waxwings. Mammals like deer eat berries and twigs.
Max Height: 15-30 feet.
Urban Planting Tips: Prefers partial shade and well-draining, acidic soil. Avoid compacted areas and overwatering.
Vine Maple (Acer circinatum):
It stabilizes soil, provides cover and nesting sites, and supports pollinators. It hosts moths, butterflies, and sap-feeding insects. Birds like grosbeaks and mammals like chipmunks and deer consume seeds and twigs.
Max Height: 15-25 feet.
Urban Planting Tips: Thrives in partial shade and moist, well-draining soil. Great for small yards or as part of a multi-layered planting.
Cascara (Rhamnus purshiana):
Provides nectar for pollinators, berries for birds, and shade for soil health. Attracts bees, butterflies, and birds like waxwings and thrushes. Bears and other mammals feed on its berries.
Max Height: 20-40 feet.
Urban Planting Tips: It does well in sun or partial shade and in moist, well-drained soils. Avoid planting near sidewalks, as roots can lift concrete.
Beaked Hazelnut (Corylus cornuta): Beaked hazelnut stabilizes soil and provides dense cover and forage for wildlife. Its nuts are a critical food source for many species, enhancing biodiversity in understory habitats. It attracts pollinators like native bees and supports the larvae of moths and butterflies. Squirrels, chipmunks, deer, and bears rely on their nuts, while birds like jays and woodpeckers feed on them.
Max Height: Typically grows 10-15 feet, forming a dense, bushy habit.
Urban Planting Tips: Thrives in partial to full shade but can tolerate sun. Prefers moist, well-drained soils but is adaptable to various conditions.
The Shrub Layer
Made up of saplings and woody plants like ossoberry and blue elderberry, this layer supports browsers like deer and insects, including mosquitoes. Some of the major plants that make up the shrub layer of a forest are:
Snowberry (Symphoricarpos albus): Offers shelter for birds and small mammals; stabilizes soil and prevents erosion. Attracts pollinators like bees and moths. Birds like towhees and thrushes eat its berries; small mammals use it for cover.
Max Height: 3-6 feet.
Urban Planting Tips: Grows in various soil types and tolerates shade, making it great for urban rain gardens or under canopy trees.
Salal (Gaultheria shallon): Excellent ground cover for preventing erosion; provides food and shelter for wildlife. Bees pollinate its flowers, and birds (such as thrushes and jays) and mammals like deer eat its berries.
Max Height: 3-7 feet.
Urban Planting Tips: Thrives in partial to full shade and acidic soils. Ideal for woodland gardens and under taller trees.
Produces Food: Yes, sweet berries are edible for humans and wildlife.
Osoberry (Oemleria cerasiformis): One of the first shrubs to bloom in spring, providing essential early-season nectar for pollinators and food for wildlife. Supports native bees and butterflies. Birds like robins and cedar waxwings eat the berries. Deer browse the foliage.
Max Height: 6-16 feet.
Urban Planting Tips: Prefers partial to full sun and moist, well-drained soil. Works well in naturalized areas or mixed hedgerows.
Salmonberry (Rubus spectabilis): Stabilizes streambanks and moist soils while providing food and cover for wildlife. Flowers attract bees, bumblebees, and hummingbirds. Berries are a favorite for bears, deer, squirrels, and birds like robins and cedar waxwings.
Max Height:Typically grows 3-10 feet, forming dense thickets.
Urban Planting Tips: Prefers moist, rich soils in partial to full sun but can tolerate some shade.
It is best planted near rain gardens or alongside water features to replicate natural conditions. If necessary, prune to manage the spread.
Produces Food: edible orange-red berries enjoyed by both wildlife and humans. The berries are tart and can be eaten fresh or made into preserves.
Thimbleberry (Rubus parviflorus): Provides erosion control on slopes and streambanks while offering habitat and food for wildlife. Flowers attract native bees and butterflies, supporting pollinator populations. Berries feed bears, deer, small mammals, and birds like wrens and grosbeaks. The foliage also provides cover for small wildlife.
Max Height: Grows 3-8 feet, with broad, soft leaves creating a lush appearance.
Urban Planting Tips: Thrives in partial to full shade with moist, well-draining soils. Its tolerance for dappled light makes it perfect for planting under taller trees.
Produces Food: Produces sweet, edible red berries for humans and wildlife. These soft and flavorful berries can be eaten raw or used in jams and desserts.
Pacific Rhododendron (Rhododendron macrophyllum): Known for its stunning flowers and evergreen foliage, the Pacific Rhododendron plays a critical role in stabilizing soil and preventing erosion, especially on slopes and near streambanks. Its flowers attract a range of pollinators, including bees and butterflies, while its dense foliage provides shelter and cover for wildlife.
Max Height: Reaches heights of 6-10 feet, with large, leathery leaves that add structure and richness to the landscape.
Urban Planting Tips: Prefers partial to full shade and thrives in moist, well-draining soils. It is particularly suited for planting in shaded woodland gardens, under taller trees, or along the edges of wooded areas in urban environments.
Western Azalea (Rhododendron occidentale): The Western Azalea brings beauty and biodiversity to urban gardens. It supports pollinators like bees and butterflies with its fragrant, showy blooms and offers habitat for birds and small mammals. This plant plays a role in maintaining ecosystem health by attracting beneficial species and providing food and shelter for wildlife.
Max Height: Grows up to 6-8 feet, with delicate, fragrant flowers and deciduous leaves that add seasonal interest to landscapes.
Urban Planting Tips: Prefers partially shaded areas with moist, acidic soils. This azalea thrives under the canopy of taller trees or in spots with dappled sunlight, making it an excellent addition to woodland gardens and shaded urban yards.
The Herbaceous Layer
Grasses, wildflowers, ferns, and other nonwoody plants dominate this layer. It provides food and shelter for snakes, mice, and other small creatures.
This list focuses on herbaceous plants adapted to the shaded conditions of Oregon's forest understories.
Inside-Out Flower (Vancouveria hexandra): Provides ground cover to stabilize soil, retains moisture, and suppresses weeds. Attracts native bees and supports pollinating insects. Small mammals use it for cover.
Urban Planting Tips: Thrives in partial to full shade and moist, well-drained soil. Great for shaded borders or under trees.
Western Trillium (Trillium ovatum): Provides early-season nectar and pollen for pollinators; helps stabilize forest soil. Attracts bees and ants, which disperse seeds. Deer and rodents may browse on foliage.
Urban Planting Tips: Plant in deep shade with rich, moist soil. Avoid areas with heavy foot traffic, as they are sensitive to disturbance.
Vanilla Leaf (Achlys triphylla): Acts as a ground cover, prevents erosion, and deters pests with its aromatic leaves. Provides shelter for insects. Deer avoid eating it due to its strong scent.
Urban Planting Tips: Prefers full to partial shade and moist, well-drained soils. Excellent for naturalizing shady areas.
Piggyback Plant (Tolmiea menziesii): Provides dense ground cover to retain soil moisture and control erosion. Attracts small insects and provides cover for amphibians and small mammals.
Urban Planting Tips: Thrives in shady, moist areas. Great for container planting or as a ground cover under trees.
Wild Ginger (Asarum caudatum): Offers ground cover, prevents soil erosion, and supports soil organisms. Flowers attract flies for pollination. Small mammals and amphibians use it for cover.
Urban Planting Tips: Thrives in deep shade with moist, rich soils. Ideal for under trees or shaded perennial beds.
Sword Fern (Polystichum munitum): Sword fern is a robust, elegant groundcover that helps control soil erosion while fostering a healthy, diverse soil ecosystem. Its lush fronds shelter small mammals, insects, and amphibians, supporting local wildlife.
Urban Planting Tips: Sword fern flourishes in partial to full shade and moist, well-drained soils. It's perfect for planting in shaded woodland areas, under trees, or along the edges of perennial beds, where it creates a rich, verdant backdrop.
Forest Succession: A Cycle of Renewal
Forests are ever-changing, cycling through growth, death, and regeneration stages. This process, known as succession, is influenced by natural and human-caused disturbances. For example:
Natural Disturbances: Events like wildfires, storms, and insect outbreaks create opportunities for establishing new plant and animal communities.
Human-Caused Disturbances: Logging, urbanization, and farming can alter forest composition and structure.
Succession begins with hardy pioneer species, such as grasses and sun-loving trees, which pave the way for intermediate species and eventually mature forest communities.
When a forest is newly forming or recovering from a disturbance, it follows a natural process called succession. Initially, the area was dominated by fast-growing plants like grasses and wildflowers, which took advantage of the open sunlight and bare soil.
Over time, shrubs and pioneer trees, such as douglas firs and big leaf maples, begin to establish, providing shade and enriching the soil with nutrients. As these trees mature, they create conditions that favor more shade-tolerant species like hemlocks and cedars, gradually shifting the composition of the plant community.
Eventually, the ecosystem reaches a stable climax community, where long-lived trees dominate, and the forest supports diverse plants and animals. This cycle continues as natural disturbances reset the process, allowing the forest to evolve and regenerate.
When we install a new forest, it mimics the natural process of succession, starting much like a newly disturbed area. Initially, the landscape is dominated by fast-growing grasses and wildflowers, which help stabilize the soil and attract pollinators.
As the ecosystem develops, shrubs and pioneer trees like douglas firs, big leaf maples and Oregon White Oaks take root, enriching the soil with organic matter and providing shade. Over time, these early species create the conditions for more shade-tolerant trees, such as vine maple and cascara, to establish and gradually create the understory.
Eventually, the forest matures into a stable, self-sustaining ecosystem that supports diverse plant and animal life. By intentionally planting forests this way, we accelerate natural regeneration and create thriving habitats that will evolve and sustain themselves for generations.
How Can Rewilding Benefit Portland?
Rewilding Portland, Oregon, with a focus on forests, can profoundly impact the city by restoring critical habitats and natural systems that are essential for the environment and its residents. By reintroducing native trees, shrubs, and plant species, we can help balance the urban ecosystem, mitigate the urban heat island effect, and improve air and water quality.
Forests, in particular, act as natural sponges, absorbing rainfall, reducing flood risks, and stabilizing soil. They also provide homes for wildlife, support pollinators, and enhance biodiversity, creating healthier ecosystems within the city. Additionally, forested areas help filter carbon from the air, improving local climate conditions.
Beyond the environmental benefits, urban forests offer tranquil recreational spaces, encourage physical activity, and boost mental health by connecting residents to nature. Portland can revitalize its natural landscape by focusing on rewilding efforts that include forests and creating a more resilient, vibrant city for future generations.
A Web of Life
Rewilding Portland with a focus on forests can transform the city by restoring critical habitats and natural systems that support the environment and its residents.
By reintroducing native trees, shrubs, and understory plants, we can rebalance the urban ecosystem, cool the city, and improve air and water quality. Forests act as natural sponges, absorbing rainfall, reducing flood risks, and stabilizing soil while providing wildlife shelter, supporting pollinators, and increasing biodiversity.
They are crucial in filtering carbon, improving climate conditions, and creating a thriving urban environment. Beyond these benefits, urban forests offer peaceful spaces for recreation, inspire physical activity, and enhance mental well-being by reconnecting people with nature. Prioritizing forested rewilding efforts will restore Portland’s natural landscape and ensure a healthier, more vibrant city for future generations.
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