9 Principles Of Natural Garden Design
It's time to bridge the gap between gardens and nature. Our gardens don't have to be separate from nature, in fact, we would all be better off if they weren't!
Traditionally, gardens have been a toxic way of controlling nature to suit our own idea of the 'perfect landscape'. Traditional gardening principles put an unbalanced emphasis on aesthetics with little thought given to ecology or how plants interact with each other. This results in static, ecologically dysfunctional outdoor spaces that require copious amounts of inputs (time, money, weeding, watering, etc.) to maintain because they are constantly fighting natural processes.
On the other hand, natural garden design seeks to work with nature. However, this is about more than just the plants you choose - It’s about changing your mindset.
We can’t approach natural garden design with a traditional gardening mindset if we truly want to reduce maintenance, increase wildlife value and ultimately have a healthy yard.
In this article we will explore how natural garden design requires a different mindset to that of traditional horticulture. Embracing these principles will help you on your journey to reaching an ecologically sound, low maintenance, naturally beautiful garden.
Table of contents:
1) Eco-regions, Not Hardiness Zones
Most gardeners have become accustomed to choosing plants based on hardiness zones. However, in natural garden design, this is not an appropriate measure of whether or not a plant is suited to your area.
In the USA, hardiness zones are based off minimum winter temperatures. In Canada, they are based off a wider variety of climatic conditions, including rainfall, frost-free periods, maximum snow depth, and more.
In both cases, these zones are helpful in telling us what plants from around the world will grow in our gardens (still useful if you are choosing fruit trees) but they do little to nothing to tell us what plants will benefit local ecosystems.
An issue with hardiness zones is that a plant from British Columbia can have the same hardiness zones as a plant from Nova Scotia on the other side of the continent! However, just because a plant can survive in another area, it does not mean that it is beneficial to the local ecology.
The problem is that these two regions have different native plants, animals and ecological communities. Plants from these two regions are simply not interchangeable in an ecological sense.
The solution is to forgo hardiness zones when choosing your plants and instead focus on a more accurate categorization for ecological value - eco-regions.
Originally designed for use in nature conservation, eco-regions are holistic representations/categorizations of major components of ecosystems such as temperature, hydrology, geology, elevation, native plant and animal communities and others.
Eco-regions are essentially communities of compatible plants and wildlife that are endemic to a particular region. If we choose plants this way, they will grow much better together and provide higher value to local ecosystems.
Eco-regions are divided into three levels with increasing specificity. Level 1 is a broad overview while level three is much more specific. I recommend sticking to level 2or 3 as level 1 is rather broad. The goal is to get as local as possible here without restricting plant availability for your design.
You may also notice that ecoregions don’t follow political boundaries. Plants and animals don’t, nor will they ever, acknowledge arbitrary man-made political boundaries. Political boundaries, like hardiness zones, should not be used as a way to choose plants.
Before choosing plants, figure out what eco-region your site is located in then start to research what plant & wildlife communities can be found there. This leads us into our next point: Gardening with plant communities.
2) Think Plant Communities, Not Individual Specimens
This prairie garden was designed with plants that are naturally found together in Ontario’s tallgrass prairies.
In nature, plants don’t grow separate from each other. They grows as part of diverse, interwoven communities of compatible plants.
As the result of thousands of years of evolution, these plants have not only adapted to specific site conditions but have adapted to fit between other plants of the same community, both above and below ground, and have found their niche in the ecosystem.
On the other hand, traditional horticulture places plants primarily based on aesthetics with little to no thought given to the ecology of how plants interact with each other. These random plant combinations will either lead to plant mortality or a high maintenance landscape that requires constant attention/babysitting in the form of watering, annual mulching or constant weeding.
The solution to this is to choose the ecosystem that your site most resembles and design your plant choices around species that grow there.
For example, a well-drained, sunny garden may best resemble the tallgrass prairie ecosystem that once covered significant parts of Southern Ontario. Not only will plants from this ecosystem be better adapted to the site but they will be better adapted to growing with each other.
This also results in more aesthetically pleasing landscapes because the plants work together to create visuals that we can relate to. In other words, a well designed prairie planting will evoke a feeling on being in a real prairie.
3) Stop Amending Soil
Butterfly Milkweed thrives in sandy soils. Amending it with compost would only encourage weeds.
Traditional horticulture teaches us that “poor” soil must be amended with compost, peat moss or synthetic fertilizer, especially if attempting to grow “the perfect lawn”.
The reality is that, in most cases, there is no such thing as poor soil - only poor plant choices.
Natural garden design seeks to reduce cost and labor in the landscape by embracing the current environmental conditions (soil type, moisture, etc.) of a site and working within them. I recommend working with your sites current conditions even if this means using a slightly more limited palette of plant species (this is usually due to limited commercial availability, rather than a lack of suitable species).
For example, lets take a look at that dry, sandy site in your garden. Traditional horticulture would tell us to add compost and spread mulch, to add nutrients and increase water retention, then install an irrigation system to keep plants well-watered.
That sounds like a lot of (expensive) work!
On the other hand, if appropriate plants are chosen for the site, such as the very-drought tolerant Butterfly Milkweed or Pearly Everlasting, then adding amendments is a waste of time and money because these plants naturally grow in these conditions and actually prefer them! In fact, the roots of Butterfly Milkweed often rot when planted around well-used irrigation systems.
In addition, the newly amended soil (which may contain thousands of weed seeds brought in from topsoil or compost additions) will encourage weeds to thrive in newly rich soil that they couldn’t have thrived in before.
Chances are that there are far fewer weeds that can grow in that sandy soil than the newly amended, compost-infused soil.
When it comes to the use of synthetic fertilizer amendments, the effects on the surrounding landscape may be even more profound on pollinators. In fact, recent (as of Nov 2022) studies suggest that synthetic fertilizers can cause flowers to become less attractive to bees by disrupting the electric fields that help bees find the right flowers.
Who would have thought that doing less work in the garden could help the bees?
4) Cover the Ground
A dense matrix of plants of varying heights will cover the ground and push out weeds.
If you look carefully at healthy plant communities, you will notice that bare ground doesn’t last very long in nature before something is trying to grow there.
If you look at construction sites, vacant lots or areas burned by wildfire, it is only a matter of a few weeks before plants have colonized these sites. This is essentially natures way of healing itself after a natural or man-made disturbance removes vegetation.
The same laws apply to your garden which is part of nature too. Yet, all too often, gardens are dominated by neatly trimmed shrubs spaced out by a few feet of wood mulch or worse - bare soil!
Bare soil is not only an invitation for weeds but it is prone to erosion and desiccation, both of which negatively affect soil health by creating unfavourable conditions for beneficial soil micro-organisms.
Any bare soil in your garden that isn’t covered by a desirable plant is guaranteed to eventually be covered by an undesirable plant - it’s just the way nature works. Any gardener who chooses to fight nature and maintain bare soil will need to get used to perpetual weeding!
Stop fighting nature and start learning from it.
Natural garden design seeks to occupy every growing space before the weeds do. We can achieve this by using a dense, multi-layered design structure comprised of a diversity of plants of varying heights and compatible growth habits.
This method will be far more effective at controlling weeds than anything else and is the biggest contributor to creating a low maintenance landscape. It is worth spending more money on your garden upfront to get this step right otherwise you WILL be spending more time/money/labour later on trying to fix the mistake.
5) Embrace a Dynamic Garden
Let the garden express itself and evolve to take on new forms of beauty.
Our environment is, always has been and always will be, in a constant state of flux and change. Whether that change comes from seasons, climate or species adaptation, nature is never static.
Even ecosystems (gardens) created by humans are subject to this rule and require specific and intensive management practices to fight this change.
Fighting change is a concept that has come to define mainstream horticultural practices. These practices promote a relentless desire for perfectly manicured lawns, neatly pruned boxwood hedges and rows of pansies that give most human-dominated landscapes a predictable, static look.
Any plant that self-seeds “out of line” is quickly weeded out, shrubs are confined to a certain shape and landscapes don’t change dramatically through seasons. This mindset creates a relentless struggle against the dynamic forces of nature and turns weeding, pruning, mowing and re-planting annuals into equally predictable, routine chores.
It is time to accept that nature is a dynamic, ever-evolving force and our choice to control it is what makes a garden high maintenance.
The Columbines you planted might have started off under your Serviceberry but they are self-seeders and will likely move around the garden over time to fill in gaps for you, free of charge (who can say no to free plants?).
The Hoary Vervain you planted is a short-lived perennial, so it won't live in one spot forever. However, if you allow it to, it will pop up in that open patch of soil that your dog dug up, because their seeds need that disturbance in order to germinate.
Acknowledging this means that no garden will ever stay the same, but that is okay because any other approach condemns a gardener to a lifetime of weeding and re-planting to keep plants in one spot.
6) Learn to Love a “Messy” Yard
Leaving plants standing over winter is an easy, yet effective, way to increase wildlife value in your garden.
Fall and spring clean ups are seasonally marketed by gardening and landscaping services as a necessary chore in order to keep a garden in tip top shape. Beds are tilled, plant stems are cutback, lawns are fertilized, leaves are raked up and thrown to the curb and the leaf-blowers are out in full force.
In natural garden design, these chores no longer serve us well.
Our whole goal in natural garden design is to take lessons from nature. Do you ever see chipmunks running around cleaning up fallen leaves in the forest? I certainly don’t, yet we appreciate the beauty of the forest nontheless!
My point here is that your garden is not an extension of the inside of your house and does not have to be kept clean to the same standards. Not only does excessive garden clean up create unnecessary work, but it is devastating to the wider ecology of the landscape and results in a loss of winter interest.
Many wildlife species over-winter under leaf litter, rolled up in leaves, under logs, in hollow stems and many other types of features.
Routine garden clean up chores, such as removing leaves from beds and cutting back plant stems to the ground, potentially (most likely) reduce the amount of butterflies and other beneficial species that will be found in the garden next season because their habitat is now being thrown to the curb.
Leaving your plants standing over winter doesn’t make a garden look scruffy at all. It is one of the best ways to add winter interest to your yard. Anyone who has enjoyed the ice or frost-covered seed heads of a winter garden or joyfully watched finches pluck seeds from the spiky seed heads of Echinacea can attest to this.
7) Leaves are made to be eaten
One sign of a successful garden is native caterpillars eating your plants!
As gardeners, we have often been taught that insects eating our plants is a bad thing. In reality, holes in leaves is a sign of LIFE in our gardens!
I think it's safe to say that most gardeners enjoy having birds visit but most don’t realize that insects are a vital source of food for birds. In fact, about 97% of birds require insect protein to feed their young (not seed or berries), with their top choice being caterpillars.
Most caterpillars are only able to eat the native plants they have evolved with (there are exceptions) so when we choose exotic plants that they can't eat, we are essentially preventing birds, and caterpillars, from completing their life-cycles.
If you see caterpillars munching away on your plants then you know that you are feeding the ecosystem!
As gardeners, we should learn to accept some leaf “damage” in our gardens. I put the word damage in italics because once you change your mindset you realize that it isn’t damage but a sign - a sign that your garden is contributing to a healthy ecosystem and well-fed birds.
8) Find Beauty in Function
Plants should be beautiful but they should also be functional
To become an ecological gardener we have to acknowledge that plants are not here to look pretty for us, but rather, they exist to fulfill important roles in ecosystems - like provide us with ecosystem services such as clean air, water, pollination, carbon sequestration and many more.
Of course the plants we choose for our gardens should be beautiful, but they should also be functional! Fortunately, it is easy to have both beauty and function. In fact, I argue that choosing plant based primarily on function adds more beauty to our gardens than choosing plants based on looks. Here is why
If you choose Pearly Everlasting because it feeds the caterpillars of Painted Lady Butterflies and looks beautiful then your garden benefits from the beauty of the plant and the butterflies it brings to your yard.
When choosing plants, consider what their role is in the surrounding ecosystem. Do they support local specialist native bees? Do they feed caterpillars of local butterflies/moths? Will birds eat the seeds over winter?
Once we acknowledge plants’ roles in local ecosystems, our gardens become so much more than just ornaments - they become tools for positive environmental change.
9) Nature Belongs in Your Yard
Nature doesn’t only belong in conservation areas - it belongs in your backyard too!
We may think that there are enough natural areas or conservation parks outside of our neighborhood to support a healthy environment. In reality, these natural areas are becoming too few and far between to support a healthy level of biodiversity.
The natural areas that we do have are small and disconnected from each other. We call this fragmentation. When habitats are fragmented it stop wildlife from moving between them which limits their ability to reproduce or find food.
Lawns and exotic plants reduce the amount of biodiversity that a landscape can support. When biodiversity is reduced in our urban areas, people start to believe that nature simply isn’t, or shouldnt, be found in these areas. This mindset fosters a toxic relationship with the natural world where the only interaction people have with nature is in landscapes where nature is suppressed with lawn mowers, pesticides, exotic plants, etc.. This further disconnects society from nature and the life-giving services it provides us.
Nature belongs in your backyard.