Building Raised Beds (Part 1)

Raised Bed Gardening is just one of the many viable methods for laying out a vegetable garden.  In an “urban garden” setting, raised beds can be an ideal setup, if you have any type of outdoor ground to work with.  Although, to be sure, “ground” is a relative term; I’ve seen photos of amazing raised bed gardens located on building rooftops.  

A raised bed garden is, in many ways, a large-scale container garden…which is kind of how we ended up with raised beds.  It’s not an exaggeration to say there’s a slippery slope from having a few large ceramic pots to wanting raised planter beds; and that’s exactly how we got into this crazy adventure.  “Hey, remember that one time when we thought it would be fun to have a couple tomato and pepper plants in some pots?”, is a frequently used one-liner between the Rocket Scientist and I when we’re exhausted after a long day working in the garden.  

After doing our usual voracious, ceaseless, compulsive research into all the possible details, we decided to build raised beds for many reasons, including:  the ability to have “good” soil, less weeding (at least the first year), better drainage, warmer soil, fewer back aches from hunching over to tend the plants, AND it would be impossible for our French Bulldog “Gardening Assistant” to mistake our tomato beds for a place to do his “business”.

Our "Gardening Assistant" Kirin

Just as there are a variety of ways to lay out a garden, there seem to be endless ways to build raised beds.  If you want to get creative, do a quick Google search and see what's out there.  Here are a few examples from around the web:

Below, you'll find what we did last year, what we learned (both good and bad) and what changes we’ve made for this year.


Bed Size

Last year we built 4 raised beds, each 12 feet long by 3 feet wide, and 1 foot deep.  

Our four raised beds, 3' wide by 12' long

We debated for some time about whether to build eight 6’ long beds, or four 12’ long beds, and ultimately we decided that since we had the space for long beds, we would go for it.  They have worked out well, although this year's "new" beds are going to be 6' long to fit their location.  Many of the sources that I turned to, in researching raised beds, recommended building beds 3 or 4 feet wide; the logic being that you don’t want your raised bed to be so wide that you can’t easily reach the center of it.  I agree with their advice, and I've been very pleased with my 3' wide raised beds.


Bed Framing

Last year we used 2”x12” lumber for the sides of the beds, and 4”x12” lumber for the ends.  To be perfectly honest, this was overkill.  It took a while to cut the 4” thick boards using only a circular saw, and our cuts weren’t always perfect…after a while, as your apathy increases, you start to tell yourself, “Screw it, it’s only a garden bed.”  This becomes a familiar phrase...trust me.

The reality is that you can use whatever kind of lumber you want for your beds, cheap scrap will work just fine as long as you support it and seal it.  Boards that are 1/2” or 1” thick would be perfectly sufficient, you could even use fence slats if you wanted to.  Your choices are only as limited as your imagination, motivation and budget.  

This year, our two new garden beds are going to be “pretty”, well, “prettier”.  See, we have an addiction to overly ambitious projects, especially the kind that require (or encourage) the purchasing of new super-cool power tools, and the new garden beds are just that kind of project; the kind that falls within the Rocket Scientist’s department…the department that he bought a new miter saw for…and a router…very essential…um, yeah…but very, very cool.  They will be beautiful and lovely, I have no doubt.  And there will be a post about that adventure once they’re finished being built. 

For now, I've decided to increase the depth of the “old beds” from last year.  While 12” deep raised beds are “ok”, from what I’ve read, with tomatoes you really shouldn’t go any shallower than that.  And since we lined the bottom of our raised beds with landscape fabric and chicken wire, to prevent weeds and burrowing critters from uprooting our tomatoes, to give our tomatoes really deep roots, we need to go “up” with our soil, and not down.  If you have good ground soil in your garden, you can till the soil under your raised bed and skip lining the bottom.  As the plants grow, the roots will grow down into the soil below your raised bed.

The method we’re using this year to raise the walls on our existing beds is the way that, in hindsight, we would have used to build our beds last year, “if we knew then”.  Since our bottom tier is already built, we’re doing a little bit of “retrofitting”, but essentially the pieces are the same as they would be for building new beds.  We’re raising the walls of our beds up to 24” because tomatoes love deep roots.  Each side of the raised bed will be comprised of two 12” wide boards, with each board fastened to posts located in each bed corner to hold the frame together.  The posts are 4”x4”, although you could use 2"x4"s and they would do just fine.  To provide extra support, we’re adding a 2”x2” post half way along the length of the bed, on the inside.  If our beds were 6’ long rather than 12’, we would skip the extra support posts.  


Materials
8 - 12 ft long, 2"x12" boards
8 - 33" long, 2" x 12" boards*
16 - 23" long 4" x 4" posts
8 - 23" long 2"x2" posts
1 Box of wood screws, at least 4" long
Water Sealant
Roller Brush
Paint tray
Roll of landscape fabric, > 48' long
Roll of chicken wire, > 48' long
Staple gun & staples
*2"x12" boards are actually 1 1/2" thick, so to make the beds exactly 3' wide:  36" - 1 1/2" - 1 1/2" = 33"

Here's an example of our "retrofitting" goals.

Last year we nailed our raised bed frame together.  We chose to do so because, along with many other fine and fun tools, the Rocket Scientist has a very sexy nail gun arsenal and a 25 gallon air compressor.  Using a nail gun with framing nails is fast.  And I’m the kind of girl that really likes to use a nail gun.  This year we’re using screws; screws are also quick to install and most importantly, they’re much easier to remove if you decide later to do any “retrofitting” of your own.  Take it from me, the girl who loves any excuse to use a nail gun: use screws, especially if you don’t have a super-duper framing nail gun at your disposal.

Super Sexy Nail Gun

Last year we lined the bottom of our raised beds with landscape fabric and chicken wire.  We attached both layers to the underside of the beds, simultaneously, with a staple gun.  Another way to do this, one that we’re adopting for our new beds this year, is to lay out the landscape fabric and chicken wire on the ground, stake down the corners, and place the raised bed frame on top.  If you ever need or want to move your raised bed, it will come in handy.  This would be another lesson we learned the hard way.

The raised beds, upside down, after attaching landscape fabric and chicken wire

*A benefit that we discovered in building our beds 3 feet wide, is that both landscape fabric and chicken wire are sold in rolls that are 3 ft wide.  It was a big time saver to be able to avoid cutting lengthwise strips of chicken wire and landscape cloth.

Prepping your Lumber

You’ll want to use some type of sealant on the lumber for your raised beds.  The instructions will tell you to clean and sand your lumber.  I did that last year, using a mild bleach solution and my electric sander.  This year, I didn't care so much.  We did, at least, wipe all the dust and dirt off the boards with a shop rag...that counts, right?

A water sealant will protect the wood from water, rot, and other factors that can weaken the walls of your raised bed.  If you’re building beds with thin sides, say ½”-1” thick, its especially important to seal your wood to prevent the walls from breaking down.  

Last year I used a brush to apply wood sealant to all eight 12’ long boards and eight 3’ end boards.  This took way longer than it should have, and I spent an entire day doing my impression of Daniel in the Karate Kid “brush on, brush off”.  This year I got smart(er).  There are choices in the wood sealant market, and I fully endorse the kind that can be applied with a roller (or a sprayer, if you have one).  Read the label.
  

Additionally, my new, more efficient, method this year also included setting up an assembly line for my pre-cut boards.  Using a couple long 2"x4" boards and some buckets, I constructed my own factory line.  

We were able to get sealant applied to 3 sides of all the boards in mere minutes by using roller brushes.  

Do you ever have those moments where you remember your “old way” of doing something, and you wonder how you could have ever been so naïve?  Yeah, that was the feeling we had this year after we used a paint roller on these boards.

After the sealant has dried, its time for assembly.

To be continued in "Part 2"...