Lava rocks have become popular for landscaping because they’re permanent mulch and can be used as beautiful hardscapes. Some people also love to use lava locks in their fire pit constructions because they’re so good at tolerating high temperatures.
Before using lava rock in landscaping, you should think about some of the common problems you might experience with them.
Lava rock landscaping problems include the fact that they can damage your gardening equipment, such as your lawnmower’s blades. To combat such problems, you should only install lava rocks in areas of the garden where you don’t need to mow the grass.
In this article, we’ll explore how lava rocks are used in landscaping, their pros and cons, and some common lava rock landscaping problems and solutions.
How are Lava Rocks Used in Landscaping?
Lava rocks are used in a variety of ways in landscaping. For example, they can be used to construct fire pits and pathways. This is because of how beautiful and durable they are. They have air pockets that keep them lightweight, making them easy to carry around and use in different places in your garden.
Interestingly, minerals in the rock affect their color—some lava rocks can be gray, while others can be reddish-brown or black. These colors can bring a pop of brightness to dull areas of your garden.
Other Uses for Lava Rocks
- Enhancing the appearance of water features. If you have a pool or pond in your garden, you can make it look prettier by placing lava rocks around it.
- Providing a backdrop to your plants. If you’ve got an area of the garden where you’ve planted pretty flowers, you can use lava rocks as a backdrop because their rough texture will add visual interest.
- Providing water drainage. You can use smaller lava rocks in areas of your garden where you need to encourage better water drainage or collect water. These rocks absorb water effectively, which will help you to prevent giving your plants too much water.
- Using lava rock in flower beds instead of mulch. Lava rock doesn’t decompose, which makes it a convenient way to mulch your plants.
- Using them to break up the soil. Lava rock helps to break up compacted soil, so it ensures that your plants get enough nutrients and oxygen.
Pros and Cons of Lava Rock Landscaping
Lava rock landscaping has many advantages and disadvantages. Let’s explore them to see if lava rocks are worth adding to your garden.
- Lava rock is porous. This type of rock drains water well, so it won’t only encourage soil drainage for your plants but will also prevent water from accumulating between the rocks.
- It prevents fungal diseases. With less water and dampness in your garden, because you’re using lava rocks, you’ll reduce fungal diseases in your plants. You can also use lava rocks at the bottom of a planter to encourage better soil drainage and prevent your plants’ roots from becoming waterlogged, which can lead to diseases such as root rot.
- Lava rock as mulch doesn’t decompose. This is why some savvy gardeners like to use it as permanent mulch in their gardens. You can add it to your garden and then forget about it, as it only needs to be replaced every few years. This also makes it less maintenance than using organic mulch.
- Lava rock is beautiful. If you want to add some color to your garden, you can do so with the vibrant colors of lava rock. These rocks will become statement pieces in certain areas of your home and will complement the plants you’re growing. To find the most beautiful lava rocks, read our guide, The Best Lava Rocks For Your Garden.
- Lava rock works well to suppress weeds. If you want to get rid of stubborn weeds in your garden, you can use lava rock and a fabric weed barrier underneath it to effectively suppress weeds, so they don’t compete with your plants for nutrients, water, and oxygen.
- Lava rocks repel snakes. Research has found that an effective item to repel snakes is sharp lava rock. The University of Illinois Urbana Champaign reports that to make the most of lava rocks for this purpose, you should position your rocks so they’re adjacent to structures that keep snakes out. The rocks should be about three feet (0.9 m) wide and about six inches (15.24 cm) deep.
- Lava rocks can damage gardening equipment. You need to be careful where you install lava rocks because if your lawnmower blades strike them, this can damage them. When chips of the rock fly off the blades, this can also pose an injury risk to people in the surrounding area.
- Lava rocks can be blown away. If you’ve placed them in areas of the garden where the rocks will be exposed to strong winds, this could cause them to blow away. This is why it’s essential to install your lava rocks about an inch (2.54 cm) below the ground so that they won’t move around when not placed in beds. Make sure you use a border to keep the rocks in place.
- Lava rocks can be difficult to clean. When using lava rocks in landscaping, debris can get caught between them. This can be difficult to clean, making the area in which they’ve been placed look messy. In addition to this, once the lava rocks have lodged into the soil, it can be difficult to dig them out if you want to move them.
Common Lava Rock Landscaping Problems and Solutions
Now that we’ve looked at the advantages and potential drawbacks of lava rock landscaping, it’s a good idea to explore some common problems you might encounter when using them in your garden. Here are the problems and their solutions.
Problem: Your Lava Rocks are Disrupting Your Plants
When choosing lava rocks in different colors, you must first consider your plants’ requirements because lighter lava rock colors will reflect light onto the plants, while darker rocks will absorb heat, which could make the soil temperature too high for specific plants.
Always check what growing conditions your plants require before you choose lava rocks. For example, if you want to grow sun-worshiping succulent plants in a flower bed, you should consider lava rocks that are darker in color so that they will increase the soil temperature and allow your succulents to thrive.
Problem: Your Lava Rocks are Becoming Moldy
If you can see that mold has started growing on your lava rocks, this can spread mold and mildew to your plants. You’re likely to see mold growing on rocks that you’ve placed in shady or damp areas of your garden.
To remove mold, your best bet is to place the lava rocks in an area of the garden where they will get a lot of sun—mold thrives in dark, damp places. Check that your lava rocks aren’t getting too much shade from nearby structures or bushy plants, as this can also cause them to become moldy.
Problem: Your Lava Rocks are Sinking
If your soil becomes very soft during rainy conditions, your rocks can start to sink into the ground. This can make them more hazardous for gardening equipment and also ruin the visual interest you were using them for.
To prevent your lava rocks from sinking into the ground, you should use fabric that will keep them on the ground surface, such as landscape fabric or perforated fabric. To use this fabric, first, place your lava rocks on the soil, and then place the lava rocks on top of it.
Problem: Your Perennial Plants are Dying
Not all plants can thrive in the presence of lava rocks. Perennial flowers, for example, can become weaker because the lava rocks are so porous, which causes them to be unable to add nutrients to the soil. This causes nutrient deficiencies for your plants.
To prevent this problem, you will have to transplant your perennial flowers so they are not exposed to your lava rocks. Other plants that don’t really work well in lava rocks are those that require a lot of moisture or those that have large root systems.
Adding lava rocks to your garden has many benefits, such as weed suppression and soil drainage, but it also has some potential drawbacks, which you should consider.
For example, they’re not always easy to keep clean and can be blown away by strong winds. Some of the best ways to use lava rocks so that they don’t cause problems in your landscaping, include to:
- Consider your plants’ requirements before installing lava rocks, such as how much heat they require.
- Use it with landscape fabric to prevent weeds from growing in the garden.
- Keep your lava rocks out of the shade, so they don’t grow mold.