Adventures in Lasagna Gardening

Up until recently I’ve more or less stuck with raised garden beds for all of my veggie growing, but recently I’ve decided to take a different approach as a bit of an experiment. You may have heard of Lasagna Gardening or maybe sheet composting. Either way is basically the same thing. You take “green” and “brown” materials and layer them (like a lasagna — brilliant isn’t it?) anywhere from 8 to 12 inches deep. Over time the materials should decompose and give you some prime planting material.

One of the benefits of lasagna gardening is you don’t normally need to do a lot of hard labor. Just collect materials and stack ’em up. That said I chose to do a fair bit of labor to get my garden beds ready. The top 3 to 6 inches of my soil are filled with gravel and large rocks. It’s not exactly a prime planting material, so I decided to dig out a bit of a pan to cook the lasagna garden in. That was the hard part. Everything else? Cake.

You can see in the images below the progression of one of my beds, as well as sheet composted garden bed I completed about a month ago. The actual layering is the easiest thing ever. I started with a thin layer of steer manure, then topped that with sheets of wet newspaper (you can also use cardboard) to help block weeds. On top of that I put more manure (approx 2 inches) and then about 4-5 inches of straw followed by another thin layer of manure followed by 3-4 inches of leaves followed by another 1-2 inch layer of manure. Super easy. The hardest part (if you’re not digging and just stacking) is collecting the materials. Try asking neighbors or family if they have leaves, straw, stable bedding, grass clippings, manure, etc. to spare.

Once you’ve collected all of the materials just layer up and then wait around 4 – 6 months and you should have a beautiful new garden bed. You can also try covering the bed with plastic to help retain heat and speed up the composting process. If you don’t want to wait that long to plant in it you can top it up with 2-3 inches of topsoil or compost and plant directly in that.

Building a Raised Bed for Your Garden

For those who have lived in the desert you might know what it’s like to try and dig in the rocky soil. In a word, frustrating. The soil in the Phoenix area isn’t terrible, but more often than not it needs amendments such as rock removal and organic fertilizers. For those who don’t have the time, energy or desire to dig and amend the soil (and then wait) a raised garden bed is a fantastic option.

A picture of a raised garden box I builtI’ve built three raised garden beds now (click here to skip right to the directions on how to build your own). I built the first one a few years ago and just a few weeks ago built box numbers two and three (the third one I built for my mother-in-law).

The first box I built was pretty basic. Nothing more than a little bit of lumber and some deck screws. I made that box’s dimensions approximately 3 x 6 x 1.5 (in feet). When I decided I wanted to expand my garden area some by building another raised box I wanted to go just a little bit bigger. I ended up with a new box with outer dimensions approximately 4.3 x 8 x 1.5 (again, in feet).

This time, on top of increasing the size of the new raised garden bed I also decided to add a few new features: a sitting bench on top of the box and the ability to easily add plastic or shade cloth on top of the box as the weather requires.

How to build your own raised bed

Required Materials

  • Nine 8 ft 2×6’s
  • Box of 21/2 inch deck screws
  • One 6 ft 4×4

Optional Materials

  • Two 8 ft 2×6’s
  • One 10 ft 2×6
  • 1/2 inch chicken wire
  • 1/2 inch PVC pipe
  • 1/4 inch flexible PVC

Required Tools

  • Electric drill
  • Drill bit
  • Screwdriver bit
  • Miter Saw (optional)
  • Staple gun (optional)

Before you do anything you’ll want to cut the wood to size (try to get the hardware store to cut this if you can). Feel free to make variations on the size of the lumber to fit your needs.

I bought nine 8ft 2×6’s for the actual box and only had to get three of those cut (in half). I ended up with six 8ft 2×6’s and six 4ft 2×6’s. I also bought a 6ft 4×4 and had it cut into four equal pieces (the 4×4 is for extra support). Make sure to buy either Redwood or Cedar as they’ll last the longest.

That’s all the lumber you’ll need for the actual garden box (if you want to build a bench on top like I did you’ll need more lumber — directions below). Now that your lumber is cut and ready to go, let’s start with the fun stuff.

First, find a level surface to build your box on (I used the cement patio in my backyard).

Now lay down one of your 8ft boards (the 2×6) and one of the 4 ft boards (2×6). Line the edge of the 4 ft board against the inside edge of the 8 ft board and drill two pilot holes through both boards (you’ll want a drill bit that’s just a bit smaller in diameter than your screw). Now drill in your screws. Continue to connect the 2x6s until you have one entire row screwed together.

Now take the 4×4 posts and connect them to the inside of the box. Make sure you drill a pilot hole before trying to screw everything together. Now add the second row of 2x6s. Finish the raised bed off with the the third row now and you’re done with the basic box.


Options, Options, Options

Keep out Gophers

If you want to keep gophers and other burrowing animals from digging up into your garden you’ll want to install some chicken wire on the bottom of the box. This isn’t too difficult, just cut it to size and staple it to the bottom of the garden bed with a staple gun. You’ll want to use long-ish staples if you can, to keep them from popping out when you’re trying to get the chicken wire installed. Try at least 1/2 inch staples, although you’re probably better off with 3/4 inch.

Add a ‘bench’ to your garden bed

For the bench you’ll need a miter saw to cut angles into the lumber. You’ll need to start with that. You should have two 8ft 2×6’s and one 10ft 2×6. Your completed garden box should be about 4’3″ wide and 8′ long, which is why you’ll need a 10′ board for the top. Cut the 10′ board into two pieces that are approximately 4’3″ long (these should be the same length as the width of your box). Now use your miter saw to cut 45 degree angles into each end of the 8′ and 4’3″ boards.

Now all you have to do is screw the bench onto the top of the garden box. You can use the same screws you used on the construction of the box. I put a screw in every 2 feet and it’s plenty secure. Use more or less as you prefer. The corner of your box will look something like the picture to the right.

Protect your garden from the sun and the cold

One great thing about gardening in the desert is that our cold season is generally pretty short and we don’t often have to cover our plants to protect them from the cold. On the other hand, shade cloth is almost an absolute necessity during the warmer months.

With that in mind, I wanted to make it as easy as possible to put up and take down shade cloth (and plastic during the cold season). I dug around the internet and found this idea: attach 1/2 inch PVC pipe to the edge of the box and then use 1/4 inch flexible PVC to hold up shade cloth. If you built a bench for your garden box then installing the 1/2 PVC is easy. Just drill a hole in the bench and drop the 1/2 PVC in the hole. Now you can take up and put down the 1/4 inch flexible PVC whenever you need it.

Alternatively, if you didn’t build the bench then you can just attach the 1/2 PVC with a few screws and a PVC pipe bracket. Easy as pie. Here’s one last look at the finished product:

Full view of the raised garden box I built
Notice the white 1/2 inch PVC pipe I dropped in so I can add easy shade later on.

That should do it for the instructions. Good luck building your very own raised garden bed. If you have any suggestions, questions, etc I’d love to hear them. Leave it in the comments below!