The evolutionary history of native plants is the most important reason to plant native plants

The Most Important Reason to Plant Native Plants

In this episode, we’re going to look at the most important reason to plant native plants. In short, it’s because native plants share a long evolutionary history with the other life that live around them. This long-shared history has resulted in native plants being more connected with the life around them than non-native plants are. This means that a landscape filled with native plants will be more abundant than one without them. Let’s talk a bit more about why this is.

More...

This post was made possible with support from people like you.

As a thank you, patrons can gain early access to our podcast episodes and unlock exclusive content to make our living world come alive.


Posts may contain affiliate links, which allow me to earn a commission at no extra cost to you. Your purchase through the links helps me create content like this post (full disclosure).

If you’ve been following Growing with Nature for any length of time then you know I talk a lot about native plants. Native plants are one of our 5 pathways to abundance.

I’ve featured some of my favorite Pacific Northwest native plants like Henderson and rose checkermallows and miner’s lettuce. And I’ve talked a bunch about how native plants can help you deal with pests. And how native plants support picky insects and in turn the other wildlife that eats those picky insects.

But unfortunately, I often see native plants being ignored or even dismissed in gardening and permaculture circles.

It’s frustrating to me because it often leads to whole groups of amazing native food plants being ignored. And it leads to the critical role that native plants play in any landscape being ignored.

I’ve studied permaculture for quite some time now and I’m also a lifelong gardener. I’ve learned a ton from people in these circles and I have a lot of respect for them. But I’m also an ecologist.

This is why I think I get frustrated when native plants are left out of the discussion or dismissed and not viewed as more important than non-native plants.

I have a lot of respect for many of the people who dismiss native plants because they’re doing great things where they live and work so it’s frustrating when they fall short on this issue.

One reason some of them dismiss native plants is due to another type of frustration. That frustration comes from native plant advocates who argue that you should only plant native plants.

I get this frustration. Especially, if your goal is to grow food for your family and community.

While there are lots of edible native plants that I want people to grow it doesn’t make much sense to exclude non-native food plants that aren’t invasive.

For example, there aren’t really any great native fruit trees here in Western Washington. We’ve got a crab apple and a very bitter cherry along with a native hawthorn. Without apples, pears, and other non-native fruit trees we wouldn’t have much in the way of fruits here. Though we do have some great native berries.

And while there are native staple crops like Wapato and cattails I also don’t want to ignore non-native staples like potatoes.

It makes a lot of sense to combine native and non-native food plants to build a resilient and abundant food system that supports people and wildlife.

So I get the frustration when people say you should only plant native plants.

But you also can’t ignore the role that native plants play in a healthy, abundant landscape. And this is the area I want to focus on today because I don’t think people understand why native plants are needed.

I think it often comes down to a focus on the ecosystem services that plants provide. Services like providing cover for wildlife, filtering the air and water, blocking the wind, creating micro-climates, building soil, etc.

So let’s start there.

Let’s take a moment to talk about why focusing on the classic ecosystem services that plants provide is missing a critical piece of the puzzle that can lead to native plants being ignored or dismissed.

But before we do I want to take a quick moment to thank our newest patron Finley.

Thank you so much for supporting us, Finley.

The support of our patrons like Finley allows us to create weekly free podcast episodes. It takes a lot of time to create these episodes and it costs money to host them online and run our website.

Our patrons help cover these costs and provide us with the support we need to create free weekly episodes.

So a big thank you to Finley and the rest of our patrons. If you’re able to please consider supporting us on Patreon—there is a link to our Patreon page in this episode's description and show notes.

Okay, let’s get started.



Episode Resources:

Further Listening and Reading: Growing with Nature episodes and blog posts with more information about the topics covered in this episode.

Books and Other Resources

Plant List: More information about some of the plants covered in this episode.

Looking Beyond Basic Ecosystem Services

The most important reason to plant native plants is to support all the wildlife that depend on them

While some aphids are generalists many aren’t and are actually specialists that focus on specific types of plants. I found these on some of my native willows but I’ve never seen this type in my garden.

Are you familiar with the term ecosystem services?

While there are lots of ways to define this term you can think of it as the benefits that are naturally provided by a landscape to people and wildlife.

I’ve included wildlife but often discussions around ecosystem services focus on the benefits provided to people.

This is because the idea of ecosystem services was developed so economic discussions would be able to quantify and include the benefits provided by the living world. Before many of these benefits were ignored as externalities.

An example of ecosystem services would be flood control provided by a healthy flood plain filled with native vegetation. Or the role plants play in cleaning water runoff from farms.

There are lots of examples but on the level of your backyard people often focus on other benefits that plants provide.

Shade from the hot summer sun is a good example. Another could be providing shelter for wildlife—such as providing a place for nesting birds. Others are:

  • Pollen for pollinators.
  • Blocking a cold northern wind.
  • Building soil.
  • Cleaning and slowing water runoff.

And even just adding beauty to the landscape.

All of these are great benefits that plants can provide. But there is a problem with just focusing on these benefits.

Let’s start by looking at the benefit of building soil.

A plant can help you build soil in a couple of ways.

  • It can be a source of biomass—leaves, twigs, branches, etc.
  • If it’s a nitrogen fixer it can help increase the nitrogen in the soil.
  • It can prevent runoff and erosion.
  • It can feed soil life which can help build soil.

Now some plants are going to be better than others at doing this. A fast-growing nitrogen-fixing tree that regrows after being cut (coppicing) could be a great option for building soil.

The same approach can be taken to look at the benefit of providing shade from the hot summer sun. For a plant to be good at doing this it would need to:

  • Be tall enough to provide shade.
  • Have a dense structure/canopy to block the sunlight.
  • And ideally, grow fast enough to provide this benefit to the current people living on the land.
  • And of course, be able to survive on the site in mind.

When you look at it from this perspective it really doesn’t matter if the tree or other plant is native or not. What matters is can the plant provide the benefit you want in a reasonable timeframe.

But this perspective ignores the most important reason to plant native plants—their long evolutionary history with the other life around them.

Here’s the Most Important Reason to Plant Native Plants

Plant-eating insects damage leaves but also provide food for other wildlife

Our native cascara trees always show signs of caterpillars. This is great!

You can think of this evolutionary history as the place the plant has in the complex web of life. The reason we sometimes use the imagery of a web of life is that a web is all interconnected.

Every strand is connected to other strands around it in multiple ways. It’s this interconnection that results in a resilient and abundant environment.

And when a plant or wildlife species have lived in an area for a long period of time it will build more connections to the other life around it.

When you plant a non-native plant it might have some connections. Birds might eat their berries for example and nest in them. But it will lack other connections.

Wild Tip:

I’m about to dive into some numbers to help you understand this concept. All of these numbers were taken from Douglas Tallamy’s great books Bringing Nature Home and Nature’s Best Hope. I’ve put links to both of them in the resources section of the show notes. Make sure to check them out to learn a lot more about the importance of native plants and their role in supporting a complex web of life.

This lack of connections to other life is why eucalyptus trees in Australia where they’re native support 48 different insect species but only 1 insect species in California where it isn’t native.

Eventually given thousands of years other species would adapt to using eucalyptus trees in California and it would also have more connections to other life.

But that takes a long time and we’re losing species of wildlife today—wildlife that depends on the native plants they evolved with.

The greater number of connections that native plants have to the other life around them is the most important reason to plant native plants.

Wild Tip:

This is why I tend to use the presence of these connections in determining if a plant is truly native or not. I don’t worry about how long the plant has been in an area—instead, I focus on does the plant share an evolutionary history with the life around it. If not it isn’t native.

A non-native plant may support some wildlife—often these will be generalists that can use lots of plants. But many more types of wildlife won’t be able to use a non-native plant.

This is especially true for plant-eating insects which make up 37% of all animal species and roughly 90% of those are specialists aka picky. All these insects can only eat a small number of plants that they evolved with.

Sometimes a non-native plant will be similar enough to support them but even then, at a much-reduced number.

Phragmites in the Eastern United States is a classic example of this. This plant is native to parts of the United States and Europe. But the 2 subspecies have been separated for long enough that even though they’re very closely related and often considered to be the same species they don’t support the same insects.

The subspecies of Phragmites native to Europe supports over 170 species of plant-eating insects in Europe. But in the United States, it only supports 5 species of plant-eating insects.

The reason for this is simple—plants don’t like their leaves to be eaten. Plants develop defenses such as hairs and chemicals that stop most insects from eating them.

Some generalists might be able to eat them but most of the time it takes insects that have specifically evolved ways around those defenses.

When you introduce a new non-native plant to your landscape most of the plant-eating insects in your area won’t be adapted to eat that plant.

This is one reason why non-native plants can become invasive.

They have the potential to grow and reproduce far quicker because they don’t have to deal with pests eating them. The native plants on the other hand have to contend with dozens and even hundreds of native insects all wanting to feed on them.

In this situation which plant do you think will grow and reproduce quicker?

The answer is likely the non-native plant since it isn’t being eaten.

The result is the non-native plant will slowly and sometimes rapidly replace the native plants. It isn’t because nature is choosing the non-native plant over the native. It’s actually the opposite—the native plant is supporting the complex web of life due to all the connections it has with the life around it.

The non-native plant on the other hand is only supporting a handful of generalist species.

The result is less diversity and less abundance.

This translates to fewer songbirds, fewer butterflies, and just less life in general.

Supporting a Diversity of Life

Explore a food forest so you can start your own

This food forest has a mix of native and non-native plants. The majority are native but I’ve included high-value non-native plants like several fruit trees to provide more food for my family and me. This supports my family but also supports more wildlife than a food forest that only had non-native plants in it.

I want to end this episode by talking a bit about diversity. Because promoting diversity is often another reason why people sometimes dismiss native plants.

It isn’t hard to understand why people might think planting a bunch of plants from all over the world would increase the diversity of life on their property.

Because when you look at the sheer number of plants they might be right.

Especially if all they had before was a classic suburban lawn with a couple of ornamental trees and shrubs. Or even a modern farm filled with monoculture crops.

Adding in a food forest, hedgerows, and gardens filled with productive but non-native plants would result in a massive increase in diversity.

And the result will be a much healthier landscape than before—one filled with a lot more birds and other wildlife too.

But only when compared to the starting point—the lawn or monoculture farmland.

What would be missing from this system is those 90% of plant-eating insects that are picky and only eat native plants. And you will also be missing all the songbirds and other wildlife that rely on those insects for food.

The remaining 10% of generalist insects would support birds and other wildlife. But not as many as all those picky insects would.

So imagine instead that alongside your food crops you mixed in native plants.

Perhaps you grew native lupines for nitrogen-fixing instead of non-native clovers. And perhaps you mixed in some native berries, and native vegetables in your food forests.

And you could plant your hedgerows so they were mostly planted with native trees and shrubs.

Try mixing native strawberries in at the base of your fruit trees. And plant a native maple instead of a Norway maple for shade.

There are lots of other ways to mix in native plants—you just got to give it a go and experiment and see what works.

And the result will be a landscape that is even more diverse than the systems mentioned earlier. This is because of the evolutionary history that native plants share with the life around them.

That is the most important reason to plant native plants. This is why native plants are one of our 5 pathways to abundance.

If you want to help heal the living world and cultivate abundance for people, plants, and wildlife then you need to plant native plants.

And stay tuned for our next episode where we will look at why messy is beautiful. We’re going to look at why skipping the fall clean-up could make your land more abundant. So stay tuned for that episode and don’t forget to check out the show notes for more links and resources related to this episode.


Thanks to our wonderful patrons for supporting Our Mission

We're on a mission to make the living world around us come alive with abundance for people, plants and wildlife—one backyard at a time.

Patreon is a way you can support that mission with a monthly contribution. Our Patrons help us bring free weekly content to help people make the living world around us come alive—from the soil to the sky—and cultivate abundance for people, plants and wildlife. This also allows us to keep our site add free.


As a thank-you for supporting our mission, patrons gain exclusive benefits based on their support level. Benefits include early access to our podcast episodes and show notes, and instant access to our complete library of 50+ cheat sheets and other content upgrades.


Thank you, Patrons!


Newest Patrons: Cat W., Adrienne R., Kelli S., Finley, and Amanda.

Support Growing with Nature on Patreon

Follow Growing with Nature

Follow us to get help, tips and inspiration to heal the living world by cultivating abundance for people, plants and wildlife delivered to you daily:

Daron

Daron is a restoration ecologist, lifelong gardener, and founder of Growing with Nature. He created this site to help people enjoy wildlife, grow food, and help heal our living world. He has managed the restoration program for a local non-profit, and he’s applying principles of restoration and permaculture to transform his property in western Washington to forests, wetlands, hedgerows, food forests, and permaculture gardens. He holds a Masters in Environmental Studies and an Associate of Applied Science degree in Water Resources. He loves sharing the joy of growing food with his two beautiful children.

>