23 May Retaining Wall Ideas (and how to know if your yard needs one)
Let’s look at different retaining wall materials which handle slopes in Minneapolis/St. Paul yards. Retaining walls, of course, aren’t always necessary. If you just want to keep your hill from eroding, and it’s not too steep, oftentimes sod or mulch and some plants will do the trick. If you want to USE the sloped areas, you’ll need to make the space flatter. In some cases, this can be done with grading in more dirt, or changing the dirt you have. But it’s not always practical (or cost-effective) to regrade your whole yard just to make a flat spot to put a patio.
Retaining walls allow you to create flat spaces where you want them, while leaving the rest of your property slope natural as it is now. Retaining walls support the new height and slope and make sure it stays how you want it— because the wall is “retaining” what you built up. (Clever, aren’t I?)
Below is a video of some walls we made in 2011 so the client could have flat planting beds to garden, and no longer had to mow his big front slope.
Do You Need a Retaining Wall?
Well, you clicked on this article, so in all likelihood, you DO need a wall. Right? 😉 You have an area or several areas which are not flat, or which are too low, and you want them higher so you can do something with them. Or you just want to add some structure to the hill, to make it more attractive to look at from the street. Retaining walls do all of this.
Let’s look at different materials we can use to build retaining walls.
Natural Stone Retaining Walls
Let’s look at an example photo of a Chanhassen retaining wall we built in 2017. Here we see retaining walls performing a variety of tasks.
- Get rid of the steep, non-useful hill
- Provide flat sidewalk spaces in between steps, so you can walk up this hill easily.
- Create flat spaces for gardening
- Provide an attractive foreground for the house — curb appeal
These walls are made of Fondulac limestone, which gives a formal look.
Here’s another example of using natural stone retaining walls in Edina to create flat space for a patios, an outdoor fireplace, and steps/walkway to get up and down the hill. These walls are Weathered Chilton Limestone. This was a total transformation of this space, and it’s all thanks to retaining walls (and my wife’s design, my crew’s amazing installation, great clients, etc, of course.) 🙂
Before this project, they barely had a 10×10 area of flat space anywhere. With retaining walls, we were able to create over 500 square feet of usable, attractive outdoor space. This is where landscaping truly can add value to your home, both for you to enjoy and for when you go to resell someday.
We won a Minnesota Nursery and Landscape Association Award for this project in 2010.
The rear part of this project needed a wall to hold up the fireplace patio, but this wall will never be seen. It faces the woods. So we used boulders for this one. Don’t worry about that fireplace so close to the edge of the wall– it’s resting on eight-foot deep footings. The wall doesn’t have to hold any of its weight.
Just one more photo of a sawn limestone. This means the top and bottom are sawn flat to a consistent height, so there’s very little gap between each row of stones. This has a really nice clean look to it.
Boulder Retaining Walls
Boulders make great, strong walls as well, with a more natural, less formal look. Here is an Eden Prairie retaining wall project we won a Minnesota Nursery and Landscape Association award for back in 2004.
In this case, the retaining walls:
- Eliminate the ongoing maintenance of the old deck
- Provide flat spaces for plantings
- Provide two huge flat spaces for patios. Unlike the deck, the paver patios will need nearly zero maintenance going forward.
- Provide easy entry from the back lawn into the two sliding glass doors of the house.
Here’s the old deck:
Here’s what we replaced it with:
Boulder walls can be installed differently to look even more natural, or more formal. They don’t always have to be installed in rows like we see here. From this view (taken from the golf course), you can see that the wall still has a nice clean look. Each row has varying sized boulders, but because it is very level and flat at the top, it still looks more formal.
Here’s a different back yard where we made flat spaces for a patio, plantings, and a walking area. The swooping lines of the walls are fun to look at. Boulders can create a variety of looks and feels depending on how they’re installed.
Concrete Block Retaining Walls
Concrete block retaining walls are another option. These generally have a more “hard” appearance. There are some block designs and patterns which soften this look, but another way is to add plantings which grow on or in front of the walls, like these:
We built seats into these retaining walls in Minneapolis! We custom cut Indiana Limestone to fit the space and form the seat.
Timber Retaining Walls
Timber walls are making a bit of a comeback now that manufacturers have developed this nice CedarTone color. They’re meant to look like real cedar timbers. It’s a rich brown color which looks very natural and softer than concrete or stone. Timber walls are an especially good choice for areas which have bad access for equipment.
This property had no access for big equipment, so this was the only way to get the timbers up into the back yard. There would be no way to cost-effectively get material to where we needed it using any other type of retaining wall. It had to be timbers!
The cheapest quick and dirty retaining wall material is green treated, undyed timbers. They are not super attractive, although after a few years of weathering they will look less greenish. These timbers are fine for two situations: People who like the look, which some do! And for spots where you need a retaining wall, but it faces a direction where it won’t be seen much or ever. Below is a large timber wall we built facing the woods. For this situation, it’s the perfect choice of material.
Bonus: It was bad access, but at least we could get our small Bobcat back there.
So, after all of this, which material is right for you? Cost is obviously going to be a factor. Generally speaking, just looking at the cost for us to buy material, natural stone is most expensive, then concrete block, then timbers, then boulders. In terms of installation labor, natural stone is the hardest, then a tie between concrete block and boulders, and timbers being the easiest.
For patios and driveways, we’ve given rough pricing. It’s a lot harder with walls because so much depends on how tall the wall is, where the wall is, and so on. A 1.5 foot tall wall will cost a lot more per square foot than one which is 3.5 feet, because we spend so much time prepping the base. Adding rows doesn’t take anywhere near as long as properly building the lowest row.
So, I’m not going to try to ballpark the pricing on retaining walls. I don’t think I can be accurate enough for it to be useful. However my wife can usually give a pretty decent idea over the phone. Or head over to our photo galleries sorted by price to get more of a feel for what retaining wall projects can cost.
We’re around anytime, so feel free to call or email with any questions, or if you see something you want!