garden plants that capture carbon

Best Garden Plants for Carbon Capture (Carbon Sequestration)

In Lawn & Garden by Jamie

If you could make a difference in climate change by gardening, would you? Of course! And as a bonus, it’ll make your garden more fertile, more beautiful, and easier to take care of. Win, win, win.

So what could promise so much? Carbon gardening.

Carbon gardening is the same as carbon farming but on a smaller scale. By using specific gardening techniques, we can remove excess CO2 from the air and store it in trees, plants, and soil. And, in the process, you’ll create a healthier, more vibrant backyard garden.

In this article, I’ll share with you how to pick the right plants for your backyard and the best garden plants for carbon capture with a few suggestions to start your research. This isn’t meant to be an exhaustive list but as a place to start thinking, start imagining, and start researching. (It’s an exciting field to learn about, I promise.)

(A quick note on Latin names: they may seem intimidating, but they’ll help you pinpoint the plant you’re talking about. Plants can have so many common names that it gets confusing. And when the second word is spp., that indicates all the varieties of that genus.)

How Plants Sequester Carbon

All plants capture carbon as part of their photosynthesis process, although some do this more efficiently or more quickly than others. Plants breathe in CO2 from the air, break down these molecules into carbon, and mix that carbon with water to create sugars (AKA glucose).

Some of this glucose feeds the plant and, in trees and shrubs, becomes wood. This above-ground carbon store is released when a plant dies and decomposes.

The rest is secreted through the roots to feed the plethora of mycorrhizae, bacteria, and other beneficial microbes that in turn break down organic matter into vital nitrogen and phosphorus. These below-ground stores are released when the soil is broken up (like in tilling) or is disrupted if the population of beneficial microbes is destroyed by pesticides and chemical fertilizers.

How to Pick the Best Carbon-Sequestering Plants

The best plants are native

Native plants are better at sequestering carbon than even the most efficient non-native plants. A study from New Zealand found that when reforesters planted the “best” non-native trees, the exotic trees released 2.5 times more CO2 than native trees. While researchers aren’t sure yet why exactly this is happening, for now, stick with native plants.

Native plants also come with a ton of other benefits. They’re already suited to your conditions, so you don’t need to pamper them. This means less watering, fewer amendments, less buying things that put more CO2 in the air from manufacturing. They also provide habitats for beneficial insects and wildlife.

All in all, choosing native plants means less work for you and more time enjoying your garden!

Diversify, diversify, diversify (AKA mimic nature)

Creating carbon stores isn’t about picking the most efficient plant and planting fields of one thing. That’s the industrial agriculture method and it doesn’t work. You want to mimic nature because nature knows best.

A diverse selection of plants will support each other and make sure that something survives when the weather turns unpredictable, as climate change is doing. Instead of putting your eggs in one or two baskets, you have twenty. Most are bound to thrive.

Choose perennial rather than annual

Sure, those annual bedding petunias look so gosh darn cheerful in the garden nursery, but annuals come with two downsides:

First, you have to dig into the soil to plant every year, releasing the carbon stored there. Growing from seed or planting perennials will keep your soil and carbon stores intact — and you save time and effort by only needing to plant once.

Second, as I mentioned above, plants release their stored carbon when they die. That’s why people love trees for sequestering carbon — they live a lot longer. If you can choose a perennial over an annual, you’ll be keeping that carbon stored for longer.

Now that we’ve got the basics, let’s talk plants.

Best Types of Plants for Sequestering Carbon

Natural Prairie, Grassland, and Meadows

When people think of carbon-sequestering plants, they think of trees. But studies have shown that grasslands are even more efficient and can be a better choice. If you’re in a city or a region that is fire-prone or drought-prone (like California), then this is the best choice for you.

They also make wonderful, unusual gardens!

All three of these are a mix of NATIVE GRASSES + NATIVE FLOWERS. You need both to be successful.

Be wary of wildflower mixes or mixes that promise you an instant meadow. Just because they’re called wildflowers doesn’t mean they’re native to your area. It just means they grow wild somewhere in the world (like in Europe). This is how Purple Loosestrife became an invasive plant in North America.

I’ll detail a few native grasses in the next section, but here are a few common native wildflowers to get your research started:

  • Black-Eyed Susan (Rudbeckia hirta). Why plant daisies when you can have the more cheerful Black-Eyed Susan? They’re native to just about all of North America and they will grow in just about any type of soil and any light but complete shade.
  • Milkweed (Asclepias spp). Milkweed has a variety of species native to just about all of North America and they are an important habitat for monarch butterflies.
  • Gaillardia (Gaillardia aristata). If you’re looking for a super dramatic flower, the Gaillardia is for you. It’s native throughout most of Canada and the North and West US.

Lawn Substitutes

There’s been a lot of debate over whether lawns are actually a carbon sink. But no matter how much carbon they can store, if you have to slather them in pesticides, herbicides, chemical fertilizers, and water them constantly, they are not going to come out carbon neutral.

While a prairie garden is always going to be more effective, if you are attached to your lawn, there are a few ways to turn them from a carbon nightmare to a carbon sink. And you also won’t have to pour hours of labor and thousands of dollars into keeping them alive.

Allow your grass to grow longer. Longer grass means you burn less CO2 with your lawnmower and your grass develops deeper roots. This latter means that there’ll be fewer weeds and you’ll need to water less. Wins all around.

Leave grass clippings on your lawn. The clippings will compost in place, feeding your lawn yummy nitrogen without you having to lift a finger. If you really don’t like the look, compost them.

Add or replace with native grasses. Native grasses have much longer roots than turf grass (so fewer weeds and less watering) AND they sequester 20 to 40 times the carbon that turfgrass does. Plus they can remain green even during the hottest drought months. (Diverse mixes will perform better!)

Here are a few grasses:

  • Clover (Trifolium spp.). Clover adds nitrogen and aerates your soil, and if that wasn’t enough, their blooms will provide a food source for bees. (If that’s a problem, mow before they flower.) Clover is also super soft. Some varieties are native to North America.
  • Red fescue (Festuca rubra). A cool season, shade and drought-tolerant grass. It’s not as soft as turf grass, but it’s rugged enough for your little ones to run rampant over. Some varieties are native to North America.
  • Sedge (Carex spp.). There’s a variety of sedges native to the US and Canada that will fit your region, whether that means dry weather or rain-soaked. These low-growing, low-maintenance grasses can be grown either as a lawn or as an ornamental grass.
  • Creeping thyme (Thymus serpyllum). While native to Europe and North Africa, creeping thyme grows in most conditions, doesn’t require mowing, and handles high levels of foot traffic. Plus it smells amazing underfoot.

Shrubs

But what if you want more than grasses but don’t have space for a tree? Shrubs are the answer, especially if you’re in the Midwest where the natural shrublands have been steadily destroyed.

Because of their smaller size, shrubs are a lot more adaptable than trees. They spring back faster after forest fires. They grow to mature size faster. They’re really hard to kill. (If you’ve ever had to try to remove a shrub, you know what I mean.) Some shrubs even act as a nurse species to nurture young trees.

Here are a few shrubs to start your research:

  • Dogwood (Cornus spp.). There are so many varieties suited for wherever you live. They like dry sites, so they’re fine with little water, but you may want to choose something else for the spot in your garden where all the water pools.
  • Chokecherry (Prunus virginiana). If your yard already gets a lot of shade, then try chokecherry. They prefer the woodland understories and the edges of woodlands.
  • Juniper (Juniperus spp.). If you need a super hardy, super drought-tolerant, super versatile shrub, then the juniper is for you. Junipers can grow almost anywhere in North America, but they are most common in the Western US.

Trees

While they may not be as effective as grasslands, trees are still really effective at carbon sequestration. Plus they can provide shade for your house (keeping those air conditioning bills down) and even provide food that would otherwise have to be shipped across the country (if you can grow fruit trees).

Different trees have different positives. Fast-growing trees will store the most carbon in a short period of time. Long-living trees will keep carbon stores for longer. Trees with large leaves and wide crowns will have the most photosynthesis. And trees that are tolerant of pollution and road salt will be best for urban and suburban areas.

The best tree for you will depend on what’s native to your region, and a combination of the above. Here are a few trees to start your research:

Vegetables

Okay, I admit it. This one is a bit of a cheat! The reason I include vegetables is that so much of the produce we consume is grown with destructive industrial agricultural techniques (even organic) and shipped over thousands of miles to reach our plates. That’s a lot of CO2 that’s being released. By growing your own vegetables, you’ll cut down on pollutants before they get into our air.

Also, it’s a fact universally acknowledged that homegrown vegetables always taste better than store-bought.

(If you can’t grow vegetables, then buy from local regenerative farmers! Support them and their efforts to nurture farmlands back into health.)

I suggest starting with these relatively easy vegetables:

  • Strawberries (Fragaria x ananassa). Strawberries top the dirtiest dozen list (produce with the most residual pesticides and other contaminants) and they’re shipped in from far away. But strawberries are easy to grow either in your backyard or in a container, and as a perennial, they’ll grow for years. (Plus, you’ll find there are much tastier varieties than those commonly found in North American grocery stores.)
  • Spinach (Spinacia oleracea). Spinach is number two on the list, and it’s frightening the number of times they’re sprayed during their 40-day growth cycle. I grow spinach in my kitchen over the winter.
  • Kale (Brassica oleracea var. sabellica). Kale is number three, and another super easy to grow vegetable! Kale will keep producing all summer long and can overwinter in some growing zones, so you don’t even need to grow very many plants.

Conclusion

By planting a diverse range of carbon-sequestering plants, you’ll help fight climate change.

But carbon gardening doesn’t stop at just planting the most efficient plants. It’s also about changing our gardening practices from destructive practices like tilling, pesticides, and chemical fertilizers. Or, in essence, nurturing your soil to keep carbon sequestered and to help your plants grow up stronger and healthier. You’ll be glad you did.