If you saw my last post about my DIY Pond and Waterfall that I built, you’ll know I have been on an outdoor beautification streak this year (even though it has been miserably hot outside this summer!). One of the projects I started this year was adding a DIY Retaining Wall Flower Border around a few areas directly behind my house. In one section, in front of a large boulder (just as in my inground pond that I built, I added a small waterfall. (In case you can’t tell, I do love myself some water features!) The previous owner had used wood and the flexible plastic borders to create the flower bed borders. The wood, of course, had begun to rot and was no longer working as a border, and the flexible borders were so low to the ground that they didn’t provide much to look at, the area was pretty plain and required a lot of weed control. Here are some before pics of the area:
Here are the details on how I turned this somewhat boring section of my yard into a beautiful masterpiece (according to me anyways!).
DIY Retaining Wall Flower Border w/Waterfall Materials & Supplies:
(Please note: this post contains affiliate links. I may receive a small commission for items purchased through these links. These small commissions help to support the cost of adding to and maintaining this website).
Flower Bed Supplies (amounts will vary depending on length and height of wall):
- Belgard Quarry Riverbend Retaining Wall Block (or block of your choosing)
- Belgard Retaining Wall Caps (12x2x8)
- Rubber mallet
- Construction Adhesive
- Masonry Saw or Circular saw with masonry blade
- Pond liner
- Solar fountain water pump kit (20 Watt/360 GPH)
- Solar fountain pump backup battery
- Waterfall spillway
- Multi-hose adapter
- 3/4″ tubing
- 1/2″ tubing
- Miscellaneous rocks and boulders or slate pieces
DIY Retaining Wall Border Tutorial
A few years before starting on this project, Hubs and I removed the bushes next to the deck. Since we live in an area considered a wildland urban interface, which means we are in a high wildfire danger area, the bushes didn’t allow for 100 ft of defensible space around our home as part of fire prevention measures, so out they came! We also removed the bushes next to the fence line in the pool area as they blocked the view of the pool and just looked a little out-of-place.
Another task I undertook before building the walls was moving some of the large succulent plants to different locations on our property. Since the larger succulents were super sharp and spiky, I was worried they were going to take out the eye of a pet or small child when walking by (in addition to permanently scarring the legs of anyone daring to walk by these beautiful but a bit vicious plants)!
Once I had all the plants in the spots I wanted then, it was time to remove all the old rotting wood borders, and the flexible rubbery borders that were in place when we bought the house over a decade ago.
Once, the old borders were removed, it was time to dig out the space for the new retaining wall block borders. I used a shovel to dig out the dirt around the flower bed areas, ensuring it was level (using a level). The shovel I chose was just slightly wider than the concrete blocks I was using, so it worked perfectly for removing just the right amount of dirt.
I started on the side with the lowest ground level and worked my way to the higher side. If there is a big difference in ground height, you can also make the first level of blocks equal to the second level in the areas where the ground is higher/lower. That prevents you from having to dig out a lot more dirt on the higher side of the flower or garden bed.
Once the ground is dug out where you want it to be, it’s time to start laying the blocks. If the dirt in your area is pretty loose, you may want to consider using a rock base for the blocks. Where I’m at in Northern CA, the ground is pretty much bone dry (we are in a years-long drought here and haven’t seen any rain in quite some time), so the ground where I was placing the blocks is extremely hard. So, I chose to forgo the rock base. I started laying the blocks on the side with the lowest ground height and then worked my way around the area for the flower bed, making sure each block was completely level front to back, side to side, and with the block on each side of it. I would add more dirt if necessary to even out any high or low spots. I used my rubber mallet to ensure each concrete block was well-seated in the ground. Here’s a pic after the first row had been set into place, you can see the areas where the ground was higher and I started the first row in those areas at the height the second row will be on the lower areas.
Once the first row was complete and level, begin placing the second level of blocks on top of the first row. Use construction adhesive to adhere the top blocks to the bottom blocks, and make sure the top blocks are placed offset from the blocks below. You likely will have to use a masonry or concrete saw to cut the first block of the second row in half to ensure the blocks are evenly offset. Repeat this process for each row until your wall is at the height you want it to be. Also, do this for each retaining wall (I built three).
Once the retaining walls were at the proper height and the construction adhesive had dried, it was time to place the retaining wall end caps. These required a lot more cutting using the masonry saw as my walls were mostly curved. However, if your wall is straight, there may not be much cutting of the wall caps needed.
To start, I lined the wall caps up on the wall, making sure the caps were lined up at the front or back, depending on if the wall curved inward or outward.
Next, measure the distance between the front (or back) corner of the end caps.
Once you have the distance, divide it by 2. (In the picture above, the total distance is 2 1/4″, divided by 2 is 1 1/8″. On each of the two end caps, mark a distance that is that half distance (1 1/8″ for example), from the back (or front) corner inward.
Once the top cap is marked at the correct distance, draw a line from that mark to the front (or back) corner.
Use a masonry saw to cut along the diagonal line.
This should be done for the two side-by-side block caps. You’ll need to measure the distance between each of the adjoining wall caps and cut to the appropriate sizes. Attach the wall caps to the retaining wall blocks below using construction adhesive. Continue this process until all endcaps are cut and attached to the retaining wall. Here are some pics of the retaining wall cap additions in progress:
As I mentioned in the intro to this post, I also added in a DIY fountain with a waterfall using a large granite boulder and the curved portion of the retaining wall that rounded in front of the boulder. You can see the area here:
You can also use an area like this as a planter, but since I love the sound of fountains, and this area is right outside my bedroom sliding door, I wanted something where I could hear the running water at night if we have the slider open.
First, I added some dirt around the inner edges of the fountain area, this would allow me to stack small rocks around the inner edges to hold the pond liner in place and to hide the pond liner. I then used a pond liner to line the inside of the retaining wall and the front of the granite boulder. I used a large piece of slate to cover the liner that was against the front of the granite boulder, this also held it in place. I then stacked rocks around the edges of the pond liner, using the raised dirt underneath those areas as a place to stack the rocks around the edge. Unfortunately I didn’t get a lot of pictures of this in progress, but here is one I remembered to take as I was adding the rocks. Here you can see I parts of the pond liner sticking up behind the large slate piece against the boulder as well as the liner sticking up at the front of the fountain. You can also see the rocks starting to be stacked around the edges to cover the liner.
To create the waterfall as seen in the picture above, install the solar water pump and waterfall spillway (make sure the fountain/pond is filled with water, and the pump is in the water before hooking the pump to the solar panel):
- Attach the 1/2″ tubing to the water pump and cut to a size that works well for your situation. Attach the other end of the 1/2″ tube to the multi-hose adapter.
- Attach one end of the 3/4″ tubing to the other end of the multi-hose adapter.
- Place the waterfall spillway in the location it will be permanently, and use large rocks or pieces of slate to wrap around the spillway and hold it into place.
- Cut the 3/4″ tubing to length and attach the other end to the nozzle on the back of the spillway.
- Place the water pump in the fountain, filled with water. before completing the next step
- Attach the power cable from the water pump to one of the cables on the backup battery.
- Attach the other cable on the backup battery to the solar panel.
Once rocks are placed all around the inner edges of the fountain and covering any areas of the liner that are in the fountain, use scissors to cut away any excess pond liner that is sticking up out of the fountain
Make sure you solar panel is in direct sun, and listen to the beautiful sound of your new fountain! Here is a pic of the completed fountain during the day and at night (after I added some submersible solar lights to the fountain):
And here are some pictures of the finished retaining walls:
These DIY retaining wall flower borders give this area a lot more character and charm. and the addition of the waterfall makes it a calming, serene place to sit and relax. The most difficult aspect of this project is cutting the blocks with the masonry saw, but that type of saw can be rented from Home Depot, and are pretty simple to use. No more difficult than using a miter saw, accept the addition of water really helps keep the concrete dust under control!
The weight of the blocks can also be an issue for transport. We had to make several trips to Lowe’s during the project to buy more blocks. Hubs has a Tundra pickup, but these blocks are a little heavy, so we could only safely transport 50 blocs at a time. If you are going to be purchasing a large quantity of these blocks, I would recommend having them delivered from Lowe’s. It adds to the overall cost, but is worth it if needing a large amount of blocks for your project!
Now, don’t forget to check back soon for my next post, which is a continuation of this project! Come back to see how I drastically improved this area even more after adding the retaining walls! Be sure to come take a look in a week or two….