Well, we did it again.  Proving that we are capable of small feats of structural engineering, spacial reasoning, and basic math, my brother and I completed the construction of another set of raised beds last week!  

I had outlined  my initial plans for this project back in February with some uncertainty.  Between (still) yet to be determined deck plans and slightly different ideas on what would look best in this space, Mike and I found our way to an agreement: I could go ahead with my plans as long as I didn't have to spend any extra money to make it happen.  Challenge accepted!  (read that with your best Barney Stinson voice for the full effect). 
We had already purchased the wood last spring when we built the other raised bed, so as far as construction went, it was really just a matter of rounding up a few tools and waiting for a rain-free day when my brother was available to help (that part took a couple of weeks, actually).  Each new raised bed is constructed out of three 4' boards, with the side of the existing "sandbox" garden as a shared wall.  We started by squaring up and assembling the three 4' boards, and then moving them in place.     
Before we could attach them to the existing garden, we needed to dig them into the ground slightly to get the new beds to sit flush with the existing bed (most of this was done from the inside, so as to disrupt the new lawn as little as possible).  Getting the new beds level and square with the existing bed was an adventure.  Since the existing bed was not level to start with, it took a little finesse to get the beds to both look and actually be level and square.  I'm quite proud of how close we got, though if you come over with either a level or a square to check our work, I'm going to have to distract you with rhubarb baked goods.
After the new beds were attached, I had to figure out how to fill them without spending any money.  Every fall we bag up all of our leaves and line them around the house for a little extra winter insulation, and every spring it takes us several weeks to fit all of our fall leaves into the yard waste bin, So I had the idea to start by adding a bag of leaves to the bottom of each bed.  This actually provides very little filler material, as the leaves compact quite a bit once soil is added, but they will start to break down pretty quickly, adding valuable nutrients to the garden soil.  
Next, we headed over to the city's public works department.  They compost all the leaves that the street sweepers collect each fall (along with other organic material they have to clear out of other public spaces) and make the compost available to residents when it's ready, free of charge.  I had no idea what the condition of the compost would be (I honestly had envisioned something with a lot of identifable organic material in it), but we were pleasantly surprised to find out it was really great soil-like compost. We also had acquired several bags of organic fertilizer (also known as manure) from a friend, free of charge, so I began to fill the beds by alternating layers of manure, compost, and black dirt from the existing garden.  I used a rake to mix in each layer as it went down. 
Once both beds were full, I added the remaining compost to the existing bed and turned it thoroughly to mix it in with the soil to make up for the soil that was added to the new beds.  This garden was disease-free as far as I could tell last summer, so I was comfortable introducing some of this soil into the new beds.  You would definitely not want to do this if you had any issues with tomato blight or other diseases in recent years.

And... the finished project!
I didn't waste any time marking off where the rows would be and getting my spinach, lettuce, carrots, radishes, beets, and scallions in the ground!  When we get a little more consistently warm weather, I'll start planting popcorn for the three sisters planting in the bed on the left, and transplanting my tomatoes along the fence.