Decomposed granite is an excellent ground covering, and it can be used for a wide variety of landscaping projects. It’s fairly simple to install too. In this article, I’ll share some of the tips I’ve learned about using “DG” for landscape projects. But first, a quick definition:
Decomposed Granite — Also referred to as DG, this type of gravel is a byproduct of granite decomposition. As the rock decomposes, or breaks down, it begins to crumble into a fine gravel-like material. It’s generally reddish brown in color, and it sometimes has shiny flecks that reflect the sunlight.
Decomposed granite can be used as a ground cover or mulch. Most plants will thrive in it, because it contains minerals. It actually helps to nourish the roots. It is often used in landscaping projects, because it’s cheap and versatile. It’s also commonly used on hike-and-bike trails.
Note: Decomposed granite is often referred to as crushed granite. From a landscaping perspective, however, they are not always the same product. DG tends to be reddish-brown in color with a fine grain. Crushed granite can be gray in color and have much larger chunks, like a standard gravel. Keep this in mind when you’re shopping around and getting price quotes. I’ve seen many supplier websites with cost estimators that had different prices for DG and CG.
This is what it looks like when it’s installed in low-water or “xeriscape” yard projects. You can see the decomposed granite on both sides of the driveway in the picture below. There’s also a dry stream bed in this design, which adds visual interest.
Below is another picture of decomposed granite being used for landscape purposes. This is a yard in Arizona, a climate where people commonly use desert landscaping design (a.k.a. xeriscaping) due to the lack of rainfall. Here, the homeowner has created a simple, low-maintenance design with DG as the ground covering. Note the use of agave and other drought-tolerant plants.
DG is a popular material in residential landscaping, especially in arid climates. But it’s also widely used in commercial landscape design. The picture below shows a government building in Tempe, AZ. This is the main office of the East Valley Bus Operations and Maintenance Facility. This building features a beautiful example of desert landscaping / xeriscaping. Note the decomposed granite installed on the right side, around the rows of agave plants. The left side of the design features rows of barrel cactus plants, along with a DG / gravel mixture.
This picture illustrates one of the key benefits of using DG in landscape designs. It tends to stay put. It doesn’t blow away like dirt or wood mulch. This makes for easier maintenance. If leaves or trash collect in the garden, you can simply use a leaf blower to blow them away (or into a corner for collection and bagging).
After installing the DG, you can give it a light spray with a garden hose. This will help it settle into place. Rain performs the same function. Once the DG has been set, you can use a blower on the low setting to get rid of leaves. It’s an easy cleanup process, and one of the many reasons I love to use decomposed granite for landscaping projects. It stays where you put it.
How to Install Decomposed Granite
So how do you lay decomposed granite? It’s actually very simple. You basically just dump it and spread it wherever you need it. Some basic ground preparation is needed, though. And proper containment is a must. So let’s cover some of the basics…
- The first thing you need to do is find a store that sells DG in amounts suitable for your project. If you’re doing a residential / back yard type of job, you’ll be happy to know that most Home Depot stores sell DG. You can buy it small bags, just like you would purchase mulch or soil.
- For large projects, you’ll want to have a truckload of the stuff dumped in your driveway. Then you would simply wheelbarrow it to the project site, dump it and spread it.
- The cost of decomposed granite varies based on availability and the color you choose. The larger stone yards might have a half-dozen or more colors to choose from. Quotes: You can use the link at the top of this page to get a quote for professional delivery, installation and landscape design.
- Tip: Decomposed granite never goes as far as you think it will. You have to lay it down pretty thick, in order to cover the area well. So when in doubt … buy extra bags. You can always save them for future spot treatments, if you have extra.
- DG spreads easily. This is a good thing, because it makes it versatile as a ground cover or mulch. But it also means you need some form of containment. Without borders, the wind and rain will wash away your decomposed granite. It stays in place better than dirt and wood mulch, but it’s certainly not impervious to a strong wind / rain storm.
- If you’re filling your entire yard with decomposed granite (which is common in hot climates like Arizona), you can use the driveway and curbs for containment. You can also install some kind of border or edging material, which is commonly available in hardware and garden stores. When creating DG walkways and paths, you can use the aforementioned edging material, wooden timbers, bricks or blocks.
- If you’re removing grass or weeds in order to install the decomposed granite, be sure to remove it all … right down to the roots. For a small area, you can use the flat side of a pick to scrape the ground clear. Keep going until you don’t see anymore roots.
- You should also lay down some heavy weed-blocking material. The gray cloth stuff works best. It’s usually labeled as “commercial grade” weed blocker. Stay away from the black mesh stuff — weeds can grow right through it.
- I recommend putting down at least two layers of the weed-blocking fabric (more is better). This will prevent weeds and grass from growing up through the decomposed granite later on. Remember, you can’t mow or weed-eat an area with DG, so you want to prevent that stuff from growing back! The extra effort up front will save you plenty of time and hassle down the road.
- After you install the decomposed granite, it will stay put fairly well. It sort of “sets” a bit, once it has been exposed to the elements. So it would take some gale-force winds to blow it away. Even so, you will have to lay down some additional DG over time, in order to cover any bare spots. This is a quick and easy process. Just dump the new DG on top of the old. It will look like it’s a different color at first, but don’t worry — the sun will blend it after a few days.
So there you have it, a comprehensive guide to installing decomposed granite for landscaping purposes. I hope you found this lesson helpful. Good luck with your landscape design project. If you have any questions about this topic, just use the comment box below.