Weeds are unwanted plants that often make your garden or driveway look unkempt and disorganized. Luckily, a layer of gravel makes for an excellent way to keep them at bay, but how deep does gravel need to be in order to help prevent weeds from growing in your garden or driveway?
A gravel layer needs to be about 3 to 5 inches (7.62 to 12.7 centimeters) deep to prevent weeds from growing in your garden. This depth is sufficient to keep weeds from coming up to the surface and ensures your garden stays pleasing to look at.
The rest of this article will focus on how gravel helps control weeds, common weed plants to look out for, and how to stop these weeds from growing through the gravel. Let’s get started!
Does Gravel Help Prevent Weeds From Growing?
Weeding is probably the most stressful aspect of growing and maintaining a garden. Weeds compete with your plants—including vegetables and flowers—for essential resources like sunlight, soil nutrients, and water. Therefore these weeds can affect your garden’s aesthetics and stunt plant growth.
However, gravel remains one of the best materials you can use in your garden and driveway to prevent unwanted plants from growing in that space.
The material provides some shade to the soil and prevents beneficial amounts of sunlight from reaching the soil’s surface. This stops weed seeds from rooting and breaking through the ground and can also disrupt the weeds’ development cycle.
Gravel can also affect weed seeds that manage to sprout or root. The material’s density will prevent most plants from emerging to the surface, reducing their chance of survival.
Still, some weeds are hardier than others. These plants will grow through gravel—regardless of how deep or efficiently you cover the soil. I’ll explore these types of weeds in the next section.
What Types of Weeds Can Grow Through Gravel?
Weeds refer to unwanted plants, and there are as many weed species worldwide as there are plants—millions. Each of these species has its own unique vegetative and adaptive features for thriving and surviving. However, very few weed species can survive being wholly covered under layers of gravel—no matter how tenacious the plant might seem.
Here are three of the most common types of weeds that can grow through gravel:
- Broadleaf weeds
- Grassy weeds
- Woody weeds
Let’s see what makes these plants so tenacious.
Broadleaf weeds are plants that have annual, biennial, and perennial life cycles—making them a hassle for you to manage effectively. These weeds can take over your garden within a week or two if you don’t maintain your space as well as you should. They’re also famous for being fast growers.
Some popular broadleaf weed species that you can see breaking through your gravel include:
Their leaves are relatively broad compared to other weed types, making them easy to identify. Some species of broadleaf weeds can break through the surface of gravel and can be extremely hard to pull out. The plants often have moderately strong root systems that may make uprooting a challenge.
Grassy weeds are another class of common weed types. These plants are true grasses that develop from seeds into a single leaf. Their hollow and rounded stems give the plants enough force to push through gravel bedding.
Grassy weeds also often consist of long leaves with parallel veins.
And while most people use them as ornamental plants for lawns and porches, they can be a problem when they grow in garden beds and driveways.
Some examples of grassy weeds include Bermuda Grass, Quackgrass, and Wild Fescue.
Woody weeds may look like flowers, but they’re far from it. And unlike grassy and broadleaf weeds, these plants have a decent amount of plant tissue that allows them to grow thicker. If left unchecked, woody weeds can grow as big as small shrubs.
Due to their thick structure and cell composition, they also have enough force to move through dense gravel layers and reach the surface.
Like broadleaf weeds, woody weeds have robust root systems that make uprooting a challenge. Therefore you might need to brace yourself or use special tools if you want to get rid of them.
Most woody weed leaves are deltoid or elliptical and usually grow flowers.
How Do You Keep Weeds From Growing in Gravel? (PAA)
Gravel is a beneficial material for controlling and preventing weed growth. Still, it’s common for some plants to break through the dense layer and thrive. Fortunately, there are several ways to manage these plants and ensure they don’t take over your garden or driveway.
Here are four of the most common ways to stop weeds from growing in gravel:
- Use landscape fabric
- Use a flame weeder
- Use weed killers
- Hand-weed the garden
Let’s explore these methods in detail.
Use Landscape Fabric
Landscape fabric is one of the most common materials used to curb the development of weeds. You spread it underneath the gravel layer, which works by further isolating the weed seeds from sunlight while creating a barrier preventing more tenacious plants from emerging through the soil.
And while landscape fabric is dense enough to prevent weeds from germinating, it’s still loose enough to allow water into the soil.
However, maintaining landscape fabric can be pretty challenging, especially as time passes. Soil that gathers on the fabric can facilitate weed growth, defeating the entire purpose of the material in the first place.
Therefore, I recommend using landscape fabric as a short-term measure for controlling weed growth.
Use a Flame Weeder
Flame weeding is an exciting practice that involves the use of quick bursts of flames to kill weeds. Contrary to popular belief, it doesn’t mean you need to burn the weeds. Instead, the practice involves passing a flame over weeds long enough to kill their plant tissues.
This method saves time but doesn’t wholly kill plant roots. Therefore, while it’s an excellent measure for annual plants, it doesn’t work for perennials as effectively.
So, I recommend you use other forms of weeding in addition to flame weeding if you’d like to use it as your main form of maintenance.
When using flame weeders, you must never point the flame directly at the plant. I recommend positioning the burner a few inches away from the plants you’re trying to kill. The heat from the fumes is enough to get the job done.
Use Weed Killers
Weed killers are practical for driveways as well as areas isolated from your plants. These chemicals are effective for all types of plants, and they’ll kill any plant they touch. However, they can also harm ornamental and wanted plants, so I recommend using weed killers with as much care as possible.
An excellent weed killer you can use is the Ortho GroundClear Year-Long Vegetation Killer 1 (available on Amazon.com). Its fast-acting formula kills any plants in the soil within 3 hours of use. This product can also leach into the ground and kill plant roots, so it’s perfect for perennials and more tenacious weeds.
Hand Weed the Garden
Hand weeding involves uprooting the weeds entirely from the soil. The practice remains one of the most natural and effective ways of killing weeds in your garden or driveway. And while this method might require relatively more effort, its effectiveness makes it a go-to when all else fails.
Getting more hands on deck is best to make the process as fast as possible. Interestingly, hand weeding is more effective than many homemade DIY solutions you’ll find online, including vinegar and boiling water.
You can also use tools like shears and hoes to make the process easier.
Still, hand weeding requires much effort if you want to do it well. As such, there’s a chance you might hurt your back in the process.
Now, Before trying any weed preventative measures described above, ensure your gravel layer sits on an excellent area. Slopes and ridges might affect the effectiveness, and you might need to level your garden or driveway before adding gravel.
Still, driveways and passageways are exceptional cases. These surfaces typically consist of 4-layer thick gravel beds to prevent weed growth.
Gravel needs to be about 3 to 5 inches (7.62 to 12.7 centimeters) deep to prevent weeds from growing. However, while this depth can help control and prevent most weed varieties, it might not be sufficient for more tenacious plants.
Fortunately, you can control these weeds using the methods discussed in this article. Finally, always remember to place the gravel layer on even and well-prepared ground for the best results.