Garden Recipe: How to Build Roof Tile Raised Beds

When we moved into our house in September, we had a roughly square area of grass in the middle of our yard. I'm not a fan of grass in California gardens--still in a drought, despite El Nino--but I am a fan of edible gardens. Duh. So the plan to swap one for the other was obvious.

After having a mixed garden of perennials (artichokes and blackberries--yes, what was I thinking? O how much I've learned) and annuals at our last house, we wanted our annual edibles to be separate from our perennials. Annuals and perennials need different things (soil tilling, fertilizer, and watering schedule to name a few).

It was also important that the new kitchen garden blended with the style and materials of the hardscaping left by the previous owners. After removing the ivy and trimming the wisteria and folding in our fava beans, we were able to clearly see the underlying structure and materials of the garden: A mix of brick, slate tiles, clay roof tile garden beds and wooden arbors. The clay roof tiles and the brick worked well together with the wood, but the slate had to go to unify the space. When planning out our kitchen garden, we decided raised beds was the way to go (I'll write another post on that later!) and copied the raised clay roof tile beds in the back.

Terra cotta roof tiles sold new are around $6 each, which isn't exactly the most efficient way to spend a gardening budget. While Craigslist did have some listings for discounted, used tiles, I ended up going to Heritage Salvage (one of my favorite places!) to buy our salvaged tiles where they were $.40 each--quite the discount! The tiles don't need to keep water off a roof, just soil in beds.

After finding the tiles, first thing to do was to swap out the slate tiles for terra cotta roof tiles in the long side bed. I then expanded the one-brick-wide path to a two brick wide one to allow future access.



I measured out two, two-foot wide paths, crossing in the middle and dividing the space into four, four-and-a-half-foot squares.

For a little while I had edging all around the beds, thinking I would plant small plants in the small spaces between the metal edging and tiles, but it looked too busy, so I eventually took it out.



I dumped the soil into the raised meds before adding the gravel to make sure the gravel stayed clean--let's be honest, messes happen when dealing with dirt and wheel barrels.

Laying down the gravel was seriously rewarding--and the crunch of that gravel? O man. Made me so happy.

After almost four days of work building the beds, we planted our about 100 starts and seeds in the raised beds, despite the beds looking pretty empty at the time of planting.

Less then two months later, we have a lush garden, bursting at the seems! I love my kitchen garden so much. 

Designing and laying out your raised beds is particular to your garden, space, and style; here are some questions to think about while designing your beds: 

• How high will your raised beds be? (With tiles, your are limited the height of the tiles)
• What dimensions will your raised beds be? (Remember, you will have to reach into the center of the bed so I wouldn't recommend much more than 2 feet from any direction)
• How many beds will have you have? (Or how many can you fit?)
• What will the width of the paths between your beds be? I recommend big enough for a wheel barrel, which is just over 2 feet.

And, without further ado, here's my garden recipe for building raised beds with terra cotta tiles.

Ingredients

Terra cotta roof tiles; I found 7 tiles makes 4.5 ft length

Soil (I used this soil calculator to figure how much I needed)

3/4 inch crushed gray gravel

Metal edging 

Tools

Rubber mallet

Tamper

Wheel barrel 

Shovel

Trowel 

Rake

String 

Stakes

Weed cloth or cardboard

Hardware cloth if you live in an area where gophers are

Elbow grease 

Instructions

1. Before doing anything: Plan. I listed a few questions above to help you get started.
2. Clear the area of weeds where you're hoping to create your raised beds.
3. Measure out your paths and garden bed boundaries; use your stakes and string to mark where these will go.
4. With your shovel, dig out the areas where your paths are going to be by 4 inches; add this soil to the raised bed areas. Use the tamper to level out the paths. 
5. Put down edging if you have any path borders that don't meet a raised bed--gotta keep those pebbles where they belong! 
6. With your shovel and trowel, dig out a narrow trench about 4 inches deep and 2 inches wide around the borders of your raised beds. Push the excess soil into the middle of the raised bed area. 
7. Place the terra cotta tiles, one at a time, into the trench; using your rubber mallet, bang the tile into the ground and then push soil to fill the trench behind the tile to stabilize. Don't bang too hard as the tiles may flake--some inevitably will no matter how careful you are, so make sure you have extras in case this happens.
8. If you do live in a gopher region, before you add your soil to the beds, line the bottom with hardware cloth.
9. Once your raised beds are made, start filling the beds with good quality garden soil, mixing in with your existing soil. Some may choose to replace all of their garden soil with new soil, but it's more economical to do a cover crop before building your beds to boost soil nutrition and mix. 
10. Rake and tramp down your soil until it is even and compacted somewhat--while loose soil is great for plants' roots to grow, too loose soil compacts over time, and will also compact the plants roots, which isn't ideal or good for your plants. I kept my soil level within 2 inches of the top of the raised beds.
11. Cut weed cloth or cardboard to fit the path dimensions. Lay the cloth and pin down with stakes. Weed cloth/cardboard will suppress/stop weeds from growing through your gravel. 
12. Spread your gravel across the path and rake until the gravel is even at a depth just shy of the 4 inches you dug out. 
13. Your raised beds are ready for your starts: Start planting!