How would I go about draining a raised garden?

Question

I am new to gardening, so I am eyeballing this first project. Please give me tips on anything I should change.

I'm refurbishing a relatively small (24 x 52 inch) raised wood garden. My current design includes mounting the legs at a variable height, so the bed sits at a slight angle. This lets the water drain to one edge. I would then drill a hole in the corner, and attach a thick cloth and wire mesh above to maintain its integrity, but be permeable enough to soak up moisture from the soil. The bottom and inside are already waterproofed.

It is 24 inches deep but I will be putting about 16 inches of soil inside. I am planning on growing (hopefully): Carrots, radish, bell pepper, tomatillo, and basil, and some flowers I actually have three separate units, so I have room to plant any natural pest repellents needed. I am in Tucson, AZ. This is just a small project so I can learn more about gardening.

I am not sure if this is a good idea, or if I am missing some key details. Please let me know how to improve it! Thank you

Answer 1

My experiment with a drainless flat raised bed has shown no problems with stagnant water. Furthermore 30cm(12") soil has proven sufficient for large plants (bigger than me).

That being said, combining plants is a topic far beyond my knowledge. Carrots expect a very aerated soil that is often watered. Tomatoes expect to never freeze and never need to deal with basic pH levels.

Answer 2

I haven't seen an entire raised garden bed inclined like that to promote drainage, but I suppose it would work.

A more common method would be to do as you describe, but leave the bed level and possibly add more drains. You are aiming for gravity to drain 1 inch or more of standing water per hour, which for a 9 square foot bed is about 5.5 gallons/hour.

I like your idea though. What's so special about flat ground? The garden you described has a good variety of plant heights in it, maybe work that into your incline and do something artsy?