Landscaping with Lava Rock

October 13, 2017


Lava rock landscaping has become quite popular in recent years. Maybe part of the excitement is that they really come from volcanoes? Either way, lava rock works best when it blends in with a natural desert landscape or purposely stands out in order to draw attention to an area of your yard, like an island. Lava rock draws a lot of attention so it’s better to leave plenty of open space with few plants if you are using very much in your landscape. If you do want to accentuate other plants, it’s important to leave them plenty of soil space.

Pros and Cons

You can mulch with lava rock. It won’t provide your gardens with nourishment, but it will last longer than traditional organic mulches that will. The dark color will also enrich your garden as far as looks go. Another pro – lava rock is a lightweight rock mulch that is easy to transport and spread. Lava rock is a very sustainable material that will only need to be replaced when it gets blown or washed away. When used in combination with a fabric weed barrier, lava rock is highly effective at keeping the weeds away. (If you have a material weed barrier underneath the layer of lava rocks, you’ll want to check it every so often, because it will likely need to be replaced sooner than the lava rocks.) Lava mulch retains heat during the day and releases it at night, cooling your plants in the daytime and keeping them warm in the evening. One con to consider is that lava rock can be difficult to remove in comparison to natural mulches that degrade on their own more quickly over time.

Things You Should Know

It’s a good idea to keep lava rock in enclosed beds only. It is a sharp material that will not only be uncomfortable to step on but could also damage your lawn mower blades.

Since lava rock is a more permanent option, it is more likely to collect dirt and dust so you will probably want a plan to keep it clean. You can simply spray them off with water, as long as you’re spraying in the direction of the proper drainage (usually whichever way the garden slopes). Don’t spray the rocks when you have anything freshly planted because it could harm new plants. If you do have to remove the lava rock to replace the underlying material, you might as well remove the lava rock and give them a good hand washing at the same time. You will want to keep the lava rock away from direct contact with plants while removing them though, to keep the material from latching onto the plant. Since lava rock attracts heat, direct contact can cause your plants to overheat. If you have a material weed barrier underneath the layer of lava rocks then you’ll want to check it every so often as it is more likely to need to be replaced before the lava rocks will. Consult a landscape center near you for more information on lava rock.