Building a Sunken Container Vegetable Garden: Part One - Two Containers

The benefits of sunken containers is similar to a raised bed. They will warm faster and you won't be stepping on the plants root systems. They also allow you to concentrate resources and grow a variety of crops. The space between them gets filled with mulch. You can let vines grow over the mulch while the weeds stay under control. The key is sinking the containers and opening holes in the bottom. The plants roots will grow through container's holes and into the ground. This provides some security from watering issues. I use recycled black nursery containers. They are easy to cut, cheap, and black to absorb the sun.

The Empty Space to Become a Sunken Container Garden.

I chose a space connected to my vegetable garden that was only getting walked on and cut. It was also away to get more growing space without discussing "another box!" with my wife.  After you find the spot, get an idea of what you want to grow and how big the containers should be. This isn't science so do your best. I create as if it is a canvas. I rarely have a plan. Some ideas work and some don't but in the end it all works out. Plants just want to grow.

The containers should be laid where you wish. You will notice the steps I used to mark the ground and cut the containers. The holes just have to be cut out in a similar manner and size. Good enough for roots. I cut lines too. The root can fit through anything.

Turned Over Where I Want Them. Holes Cut Out. Traced in Peat Moss.

Containers Removed. General Circle Traced in Peat Moss.

Remove the circle of grass to a depth of 3 to 6 inches. Less for smaller containers and more for larger containers. These containers might even be 8 inches deep. You can really go as deep as you want. If you don't want to see them... bury the containers by 1/2 their size.  Put the grass to the side. You will be doing four main things.

• Removing the grass
• Loosening the soil remaining in the circle (ground)
• Amending the soil in the circle (ground)
• Setting the container and returning the grass to it (only do this for large containers)
• *Toss the grass for smaller containers. You don't want it growing up if it isn't smothered.

Remove the Grass to 3 to 6 inches Deep. Or More if You Wish.

Loosen the Soil to a Depth of 8 to 12 inches. Nothing Fancy.

That is the Hole on the Right. It is Amended with Peat Moss. 

I am using a very large container. Smaller containers don't need this much preparation. I amended the soil in the hole where the container will be placed. It is loosened to a depth of 12 inches. I might of added some fertilizer but don't recall. Feel free to boost it with what you have available. I also placed some soil to the side (left). That will go back in the container and around the container. This doesn't have to be perfect. You aren't following a recipe.

The Container is in the Hole. The Grass is Placed in the Bottom as Chunks.

For large containers you can place the soil with the grass roots right in the bottom. The depth of soil placed in the container and on the grass with prevent growth. It is in chunks. The roots will grow through it and into the loosen soil beneath the container.

The Set Container. The Sides Filled.

The sides are filled with the soil I kept to the side. I added peat moss and soil to the bottom and a hand full of vegetable fertilizer.

The next step is filling your container. I am making CHEAP soil. I used peat moss and the cheap bag of soil I told you not to buy. I bought a bag and opened it. It turned out to be sandy and that is what I wanted. My soil is mostly clay. You never know where the soil in the cheap bags come from. This batch happens to meet my needs. I used my large 18 gallon blue container (there on left) to make the planting material. I used peat moss and cheap bags of dirt to about a 1 to 1 ratio. Lots of peat moss was used for moisture control. I also added in all the soil in the picture that I removed.

The Amended Soil Placed in the Sunken Container. 

Two Complete Containers.

They are in the garden as sunken containers and can be planted with just about anything. I will blog about planting them and creating supports for plant growth. This is a fairly quick and limited labor way to cheaply add to your vegetable gardening space. You can never have to much room to plant in your garden. Try it out and let me know what grows.