An estimated 24 billion tons of fertile soil is lost yearly due to global erosion! Imagine the Dust Bowl on a massive scale. Erosion is the accelerated loss of fertile topsoil due to water, wind, and mechanical disturbance. While our gardens may be small within the grand scheme of the planet, we can each do our part to prevent erosion. Protecting your garden from soil erosion also directly benefits your wallet, boosts crop productivity, and reduces the need for backbreaking labor.
Soil is a finite resource, meaning it cannot be recovered within a human lifespan. Once it is degraded or eroded, it is gone for the foreseeable future until weathered rocks, minerals, and microorganisms can chisel away at the bedrock and decompose dead things to form new soil.
Topsoil takes thousands of years to form and holds more than 2 billion tons of our planet’s carbon, making erosion also a climate-related issue.
What is Soil Erosion?
Soil erosion occurs when topsoil is displaced, disrupting and relocating particles.
Soil erosion is when topsoil blows or washes away due to wind, water, or gravity. Erosion disrupts and transports soil particles to another place. This natural geological process is exacerbated by human activities that leave soil barren without plant roots, organic matter, or vegetation to hold it in place.
- In gardens and farms, erosion can diminish fertility, reduce water-holding capacity, and hinder plant growth.
- In landscapes, erosion can cause major issues like water pollution, flooding, foundation issues, and land collapse.
- Over large expanses, erosion can create massive gullies in the earth, such as the Grand Canyon or the Saharan Desert.
- Erosion also creates economic devastation, like the Dust Bowl and the Great Depression in the 1930s.
Erosion can radically change an ecosystem over thousands of miles of land. Between 11,000 and 5,000 years ago, the Sahara was among the most abundant, verdant, plant-rich, and moist ecosystems in the world. There is some evidence that human activities contributed to the Sahara’s loss of vegetation and subsequent transformation into an arid desert.
Soil is expensive to import to your garden, and it must be extracted from somewhere. It takes up to 1,000 years to form just an inch of healthy topsoil! By keeping it covered and anchored in place by plants, you can prevent erosion and keep your most valuable garden resource where you want it— in your growing beds!
What Causes Erosion?
Soil can erode when left exposed to the elements, including wind, heavy rain, and flowing water.
When dirt is left vulnerable and exposed, it becomes susceptible to erosion by wind, heavy rain, and flowing water.
Think of soil as Earth’s thin, fragile layer of skin. You probably wouldn’t go out in a storm naked, and your soil doesn’t want to brave the elements without a protective layer of living plants or decomposing mulch.
The major causes of erosion across the world include:
- Deforestation and logging
- Industrial farming
- Tillage (mechanized disruption)
- Overgrazing of livestock
- Synthetic agrichemicals
- Housing and Urban Development
- Construction
- Re-routing of waterways and subsequent flooding
While these human activities set the stage for vulnerable soil, the true eroders are natural forces:
- Water (washing away soil in waterways and flooded areas)
- Gravity (sliding soil down barren slopes)
- Wind (blowing away the topsoil)
- Ice (movement of glaciers)
On a smaller scale, the most common causes of soil erosion and loss in gardens include:
- Bare soil left over the winter
- Lack of mulch
- Excessive tillage or soil disruption
- High winds and heavy storms
- Ripping out plants
- Sloped garden beds without vegetation
10 Tips to Prevent Soil Erosion
A little bit of erosion is inevitable due to the unpredictable forces of nature. We cannot control high winds or unexpected crop failures (like failed germination) that leave the soil bare. However, you can take several simple steps to protect your most valuable garden resource: the soil!
These tips not only prevent erosion but save you tremendous time and money while boosting overall yields and plant health. Happy, healthy soil yields healthy plants and healthy humans! Here’s how to keep your soil where it belongs:
1. Never Garden Naked
Naked soil can dry up, blow away, or erode into waterways, causing unprecedented loss.
When you look at healthy natural ecosystems, it is rare to find naked soil. Mountain slopes, riverbanks, and grasslands are all covered in vegetation.
Even in the desert, where the sand appears barren and lifeless, there are low-growing plants, hidden underground roots, and bacterial crusts that form over the surface to protect it from sudden rainfall.
Nature Tries to Cover Bare Skin
Nature strives to protect the earth’s delicate surface, often employing plants as its cover.
Returning to the analogy of soil as the earth’s fragile skin– Nature does everything in its power to cover her skin with a layer of “clothing.” Most often, this comes in the form of plants. The species we call “weeds” are actually early successional plants that nature uses to cover bare soil. These fast-growing, ultra-resilient species, like dandelion, bindweed, or opportunistic grasses, can establish quickly and anchor roots downward to hold soil in place, protecting it from erosion.
You see the same pattern wherever land is logged or cleared for development. Aggressive thistles, blackberry vines, ragworts, and many other invasive weeds rapidly try to take hold of the barren land. With no “desirable” native species or crops for cover, nature attempts to resolve her nakedness as quickly as possible.
If you leave a garden bed unplanted for too long, it will inherently try to cover itself by germinating weed seeds. If you don’t want to grow weeds, never garden naked!
2. Switch to No-Till
Tillage is the mechanical churning, chopping, flipping, and disturbing of soil structure. Plows, rototillers, subsoilers, and even aggressive hand digging are forms of tillage with varying degrees of damage. No-till is an agricultural method that aims to minimize disturbance as much as possible. Switching your garden beds to reduce or no-till methods can dramatically improve health and yields while reducing weeds and disease pressure.
Bulldozing the Underground City
Understanding the complexity of the ecosystem is essential for properly implementing no-till practices.
There are billions and trillions of bacteria, fungi, nematodes, protozoa, worms, spiders, and all manner of little creatures working together in a complex food web to cycle minerals, nutrients, water, and oxygen throughout the soil.
A tiller or plow is like a Godzilla-sized bulldozer plowing through the city. It destroys all the infrastructure for life, ultimately making your garden beds inhospitable to the beneficial underground allies that help plants grow most abundantly.
No-Till Practices
These methods prevent erosion, keeping the underground structure intact.
- Living Mulch: Cover crops and ground cover plants maintain living roots at all times so weeds can’t take over
- Biological Tillage: Using deep-rooted cover plants like daikon “tillage” radish to break up hardpan compaction
- Tilthing or Raking: Very shallowly preparing a seedbed by only disturbing the upper 1 inch of soil while leaving lower layers intact
- Occultation: Using tarps to smother weeds without tilling or ripping them up
These and many other methods prevent erosion because the underground city remains intact while the upper layers of “skin” remain protected. Plus, I enjoy no-till because it’s easier on the back and requires little mechanized equipment.
3. Mulch in the Fall
Erosion is most common in fall and winter due to cold climates that hinder plant growth.
Runoff and flooding happen regularly in areas with wet winters. Raindrops are actually a major catalyst for erosion.
It may seem strange to imagine that little raindrops could erode away soil particles at any major scale. Still, when you consider the winding gullies through fields, roadsides, or ditches, you can see how powerful water accumulation can be. Rain must flow somewhere, and once it starts to form a trickling stream through your garden beds or pathways, it tends to pick up anything in its track.
Best Autumn Mulches
Mulch can be applied to most areas, including raised beds, pathways, ornamental beds, and borders.
Raised beds, pathways, ornamental beds, and borders are all mulched with one of the following:
- Deciduous leaf litter (best for unused veggie beds)
- Straw (never hay, which may have seeds)
- Coniferous needles (like pine, for acid-loving plants)
- Wood chips (ideal for preventing muddy pathways)
- Compost (great for covering vegetable beds)
Any form of coverage over the winter is better than nothing. Avoid mulches that have been dyed or treated with synthetic chemicals, like many sold for ornamental landscaping. If you can’t find organic decomposable mulch or you’re in a pinch, throw a silage tarp over your garden beds to protect them from eroding in winter storms. Fall is a great time to feed your soil in preparation for the cold.
4. Use Cover Crops
To protect your garden beds when not in use, consider using cover crops.
Excellent species for vegetable gardens include:
- Winter rye
- Crimson clover
- Tillage daikon radish
- Oats
- Hairy vetch
- Winter wheat
- Cover crop seed blends
5. Keep the Roots Intact
The absence of roots in the soil leads to the displacement of particles by wind and water.
This simple plant removal or “bed flipping” technique is more gentle and can prevent erosion while boosting microbial activity underground. It also makes gardening easier! You can even use a small lawn mower or hoe to chop up the residues for low-growing crops. Add a layer of compost on top, and you’re ready to seed or transplant the next crop!
Key Caveat: Avoid leaving diseased or invasive plant roots in place. If you notice any signs of fungal infections or root rot, it’s best to rip up as much of the plant as possible and throw it away or burn it. Don’t compost infected plant matter.
Similarly, if you are facing invasive perennial weeds that spread by rhizomes or vegetative root propagation, pulling up as much of their root system as possible is crucial. If you only chop off the top of the plant, the roots will still be in the soil, ready to push up more weedy growth.
6. Practice Succession Planting
A skilled succession planter maximizes garden space by ensuring no beds remain unused.
A pro-succession planter aims to maximize garden space as much as possible, which means no bed is ever left bare. When you pull out one crop in the spring (overwintered kale, for example), you should aim to plant the bed with another plant succession immediately. If you prefer to practice crop rotation, you might put your next kale planting in a neighboring bed and seed lettuce in the bed where you just removed the kale.
No matter the rotation, the continuous coverage of crops ensures that new roots are constantly growing to hold the particles in place, preventing erosion. Moreover, microorganisms can quickly colonize new plants to aid nutrient mineralization and transport water.
At any given time, a garden bed can have a few rows of freshly seeded radishes, a row of “teenager” radishes, and a row of radishes you are currently harvesting. Succession planting ultimately makes your garden more productive, colorful, and healthy over time. It prevents naked soil and naked dinner plates!
7. Add Organic Matter
Organic matter transforms into humic acid by microbes as it fully decomposes.
While modern industrial farming methods have taught us that uniform sand-like soil is the best, this is untrue. A healthy soil ecosystem has a range of particle sizes, from tiny clays to mid-sized silts, and a wide array of differently sized clumps of organic matter.
Imagine these different particle sizes as stacks of balls. Clays are like tiny marbles or even flattened stacks of paper. Silts are like baseballs. Sands are like bowling balls.
If all of these are mixed and stacked together, they leave lots of different-sized pores for water, air, and microbes to hang out. But if you put that stack of balls through a giant blender, the sizes become uniform and sink to the bottom. There are no aggregates or varying particle sizes to support the air spaces. This is why a lack of organic matter and disturbance can cause major compaction issues.
The best ways to boost your garden’s organic matter include:
- Adding high-quality compost every season
- Planting cover crops
- Using organic mulches
- Practicing lasagna gardening when building new beds, as shown in this video:
8. Plant Windbreaks
Taller trees and shrubs effectively block wind, preventing erosion and damage to crops.
Taller trees and shrubs block wind from blowing away soil or tattering crop leaves. Better yet, hedges create a more private garden oasis where you can nurture healthy soil and plants without disturbing your neighbors. Flowering edges also create a habitat for beneficial insects and pollinators.
Here are my favorite flowering shrubs that make beautiful privacy hedges, including:
- American Beautyberry (Callicarpa americana)
- Camellia (Camellia japonica)
- Fragrant Sumac (Rhus aromatica)
- Gardenia (Gardenia jasminoides)
- Hardy Hibiscus (Hibiscus moscheutos)
- Lilac (Syringa vulgaris)
Be sure to consider the height of a windbreak before installing it, as you don’t want to shade out your most valuable crop-growing area.
9. Terrace or Stabilize Slopes
Terracing involves creating steps on the slope to farm without worrying about severe erosion.
Terracing is an ancient technique that creates “steps” on a slope to cultivate crops without risking massive downhill erosion. Each flattened terrace becomes its own planting zone. However, terracing can be very labor-intensive and expensive over large scales.
If you don’t want to move a lot of land or your slope is just too steep, the best thing you can do is stabilize the hill with quick-colonizing vegetation, especially perennial plants. Never ever leave a hillside with bare soil!
These plants are excellent for preventing erosion on slopes:
- Periwinkle (Vinca minor)
- Forsythia (Forsythia spp.)
- Creeping Juniper (Juniperus horizontalis)
- Japanese Spurge (Pachysandra terminalis)
- Elderberry (Sambucus spp.)
- Yarrow (Achilles millefolium)
- Creeping Phlox (Phlox subulata)
Hillside plants not only prevent erosion, but they create a beautiful sloping landscape that is far nicer to look at than eroding mud.
10. Retain Soil Structure
It’s best to disturb only the upper few inches of soil to aid crop germination and establishment.
These upper two layers are the most vulnerable to erosion because they are the closest to the surface and the most commonly disturbed by human activity. Nature can take 100 to 1,000 years to form just one inch of topsoil!
When working on your garden soil, always keep the cake layers intact. If your cake has rich chocolate frosting on top, you don’t want to chop it all up and flip the layers over, or you might incorporate chocolate and vanilla into the lower strawberry layer. While this isn’t a perfect metaphor, surely you can see how the integrity of the layers is important.
Inverting the soil makes it lose its natural structure and become more vulnerable to erosion. Instead, practice only disturbing the upper few inches, just enough to allow your crops to germinate and get established. Let the plant roots and microorganisms take care of the rest!
Final Thoughts
You probably put a lot of time and effort into building your garden soil, so it’s important to protect it so it doesn’t get lost in the wind. The easiest ways to prevent erosion are simply by observing and mimicking nature. Remember to:
- Never garden naked (keep the soil covered!)
- Reduce or eliminate tillage.
- Maintain living roots.
- Protect the soil layer cake.
- Mulch regularly.
- Plant cover crops.
- Plant windbreaks that won’t shade out your garden.
- Protect fragile slopes and hillsides with vegetation.
