Concrete Garden: Building

As I mentioned in yesterdays Blog, there were a number of potential problems that I needed to address before I could realistically set about building a Raised Garden Bed on my Concrete Slab. The primary problem I had to solve was of course space. Obviously I wanted to make sure that I had enough room to make a Raised Garden Bed worthwhile and I also wanted to make sure that I was going to be able to work on it from all four sides.

So I set about removing all of the items that were currently sat on the Slab before getting out my trusty measuring tape. As you can see from the picture below, the right-hand side of my Concrete Slab receives the majority of the sunlight, while the left-hand side is normally shaded throughout most of the day. With the sunlight as a guide, I worked out that I could build a Raised Garden Bed and allow myself a narrow walkway within a 48 by 80 inch area.

The next problem I had to grapple with was the type of enclosure that I wanted to use. I had already determined that I didn’t want to use a pre-fabricated enclosure. Not only would doing so restrict me from maximizing my available space, but the cost of buying such an enclosure would stretch my budget without giving me any real benefit for the added cost.

So I took a long look at the cost and strength of various Plastic and Wood Panels compared the various techniques for building an enclosure and got a little discouraged, that is until I hit upon a simple, durable and cost effective solution.

Concrete Blocks.  

Concrete Blocks would blend nicely with the underlying Concrete Slab, are durable, cheap and unlikely to be blown, flooded or moved out of place during some of the more extreme weather that we can get here in Central Florida. They are easy to fit together, don’t require any assembly and the two large holes in each block allowed me the flexibility to plant compact flowers and crops. Finally at 8 inches wide, 8 inches deep and 16 inches long, the blocks fit perfectly into my designated available space.

With my available space assigned and the Concrete Blocks assembled, the final problem I was concerned about was drainage. Unlike a conventional Raised Garden Bed which can rely on excess water draining through it and into the underlying soil, my Raised Garden Bed is going to sit on a non-porous, flat, Concrete Slab. After some research and closer examination of the Concrete Blocks, I realized that if I had a small gap underneath each Concrete Block, I could rely on gravity pushing out any excess water and the plants to drink anything that was left. In the end I decided to line the bottom of my Raised Garden Bed and its Concrete Blocks with a product called Weed Block. This relatively cheap product is in essence a fine mesh that is designed to stop weeds from pushing in to a soil based Raised Garden Bed, while allowing water to seep out. In my case, the Weed Block will lift the Concrete Blocks just enough to allow water to seep out underneath them while stopping soil from escaping and staining my Concrete Slab.  

With my building materials purchased, I measured out the Weed Block and cut it to size. I had purchased the smaller of the two rolls that were available in order to save on cost, so I measured and cut out two 26 by 80 inch strips which allowed for a little overlap when laid next to each other. I placed one strip down, aligned and flattened it out until it was in the place that I had marked out and then started weighing it down with Concrete Blocks as I made final adjustments. Finally I had one whole side assembled.

Important Note:   Each Concrete Block has a small channel on the bottom. Be sure to lay the Block down so that this channel is facing down, this channel will assist with any drainage that is needed.

Once I was happy with the layout and appearance of my initial work, I laid down the other strip of Weed Block and placed the remaining Concrete Blocks down on top of it. I then checked each block to make sure that it was snug against its neighbors and that the Weed Block covered all available space.

Once I was happy that everything was laid out correctly, I checked that the Weed Block was fulfilling its primary role by soaking the entire enclosure with water. As I watched, the water seeped out in the manner that I intended and it became clear that short of a monsoon, drainage would not be a problem.

With everything in place, the final building task for the day was to fill the main growing space and small side growing spaces with soil. While I would normally prefer to use generic soil and control the amount of fertilizer going into the garden, I ended up taking advantage of a special offer and purchased six bags of Miracle Gro which I poured in and racked. I also treated myself to a trellis with the savings and placed it with respect to the normal movement of the sun on the northern end of the garden. 

 

The last step I preformed today was to soak the soil and leave it overnight. While I was sure the Weed Block would do its work and retain the soil, I wanted to be entirely sure before doing any planting, I also wanted to let the soil breath some before planting. 

Talking of planting, check back tomorrow and see what we decide to put in our new Concrete Garden Bed