How We Built Our Tiered Raised Bed Vegetable Garden on a Slope

When we bought our house and saw the slope in the backyard, we knew we had some challenges ahead of us. The yard extended about 15 feet out at grade, and then the slope began. We wanted to plant a vegetable garden, but we were not sure how to do that on the slope. For the first two years, I planted only tomatoes in a small bed on the slope which receives a lot of sun.

Now and then, we discussed how we wanted to build some garden beds. We did not want wood because it would not last long. We would have used cedar which would last quite a while, but we wanted something a little more permanent. Eventually, we discovered some retaining wall stone at Home Depot that seemed perfect for the job. These are made by Pavestone® and they have a lip on the bottom back which helps to hold them in place. Since we did not want to mortar our garden beds, these building stones seemed like a good choice.

Upside down paving stone with lip on bottom

After doing some research, we decided to build our garden. Although I helped my husband with some of these tasks, he is really the one who built these beds. After doing a couple of them, he became very proficient at it.

To get the beds to grade we needed them to be about two to two and a half feet high, and we decided to make them about five feet wide and about three feet deep. Sometimes those measurements varied as the hill grade changed. At first, we decided on four beds. However, we later realized we needed at least two more for a total of six beds--three on each side.

Each bed is about two to two and a half feet tall

Tools needed:

Level
Rubber Mallet
Sand
Crusher run or crushed stone
Pea Gravel
Pavestone® Anchor™Windsor Stone®
Shovel
Garden Trowel
Hammer
Chisel

To begin, we dug a trench about the height of the stone to lay the first row at the bottom (down the slope) of the bed. Digging in the first row adds stability to the bed. We spread a thin layer of sand over the trench and then spread the crusher run or crushed stones. We laid the stones in the middle of the first row and worked our way around, using the level to make sure each stone was level. We used the trowel to adjust the sand and crusher run/crushed stone to level the stones out. After placing each stone, we used the rubber mallet to secure it in place.

The first row is placed in the trench to add stability for the stones above.

Once the few stones are in place at the bottom of the bed, we began working our way around the bed. The hill guided us as to when to start the next row. The first row does not go all the way around the bed because of the hill grade. After the first row, things became a bit easier because only a few stones need to be dug in as they meet the sides on the slope. The remainder of the stones are stacked on other stones. We staggered the stones by placing the center of a stone over each joint for stability.

The rows meet the slope, and then the next row is laid.

After the first bed was completed, the remainder of the beds in that row came up to meet the first bed without going all the way around as the first bed did.

The first bed's top row encircles the entire bed, but the beds down the row meet the bed before it.

We dug out some of each bed, and then spread pea gravel against the first row of stones for good drainage.  Then, we filled each bed with soil, compost, humus, and manure. The instructions from the manufacturer suggest spreading landscape fabric around the inside against the stones to prevent soil from escaping through small openings. We did not do this, but we may do it in the future. We have not really had a major problem with soil escaping.

We laid some gravel against the first two rows for better drainage and then backfilled with soil, compost, humus, and manure.

As we came around the rows setting the stones, there were times when the stones did not fit. We had to cut a few to make them fit. We used a chisel and hammer to mark where we needed the cut, and then hammered off the excess. Sometimes the stone broke at the cut, and sometimes we had to shape it a bit with the hammer.

The third stone from the end is a cut stone.

Given that we have this slope, I cannot say enough about how much I love these garden beds. They have extended our yard so we can have a vegetable garden. The beds are easy to work in and around, and they have held up without incident for four years now. Last year, we placed pavers in between the rows because sometimes the hill is slippery. And this year, we hope to create a path and a fence all around the garden because rabbits are frequent visitors.

For more information, the manufacturer, Pavestone®, has some building instructions on their site.

I am linking up with My Romantic Home for Show and Tell Friday.
©Michelle A. Potter