Blog

Mar 26 2015

Building raised garden beds with Restoration Juniper

By Tamra

Juniper raised beds

There are many benefits to constructing your raised bed with juniper lumber. Restoration Juniper is long-lasting, beautiful, and chemical-free lumber that supports family-run mills committed to restoring Northwest ecosystems. Juniper lasts much longer than cedar or redwood, up to 50 years or more in ground contact applications because of its naturally high oil content that is decay and rot resistant.

It is genuinely not a good idea to use pressure treated lumber for raised beds: the chemicals can leach into your soil and ultimately into your vegetables. So juniper is a good alternative for the environment AND your health.

Understanding juniper lumber is key to successfully building a raised bed out of Juniper.  Juniper landscape timbers come in a variety of sizes.  The most common sizes for raised beds are 2"x6"x8' and 2"x8"x8'.  Juniper lumber comes from a small tree that has a great deal of character.  Landscape grade lumber will often have some bark, wane, knots and is rough sawn. Understanding Juniper’s unique character before you embark on building your raised bed will provide a much more satisfying experience.  

Let’s take a look at what is required to build a 4-foot by 4-foot raised bed out of Juniper boards. I chose this size for our example raised bed because it makes sense from a materials standpoint, as there will be little waste. It’s always a good idea to sketch out your project first to take into account the ideal length of lumber you’ll need, as well as how many pieces you’ll need so you can get everything in one trip.

This project will require one 4x4x8 Restoration Juniper timber, four 2x6x8s or 2x8x8s depending on the height of the bed walls, coated (or stainless) 3/16” or 1/4”  (min. 3-1/2” long) flat-head or hex-head timber screws, a saw (circular or hand), measuring tape, a pencil, a carpenter’s square (or “speed” square), power drill, drill bit that matches the diameter of the shank (unthreaded portion) of your screws, a drill bit that MATCHES the diameter of the screw threads, and a driver bit (for the drill) or a socket wrench.

The first thing you need to do is decide on the height of the walls e depth of the beds. Beds that are at least 12” deep can support most vegetables.  Deeper beds with higher sides, those that are 16” to 18”, are wonderful for limiting back strain.  My own raised beds are 24” tall with a 6” ledge running around the top for sitting and for placing garden tools (and the taller beds are the perfect height for very young gardeners). 

To create a 12” deep bed you will need 2x6x8 Restoration Juniper, which can be found at Sustainable NW Wood. Our staff can help you select the Juniper that will work for your project. We’re using 8-foot long pieces because the raised bed will be 4’ long and 4’ wide. Two rows of 2x6 per side will get the 12” depth for your bed.  If you would like the walls to be taller, two rows of 2x8s will give you a 16” depth, which is close to standard chair height (for comfort). Using 8’ lengths helps to eliminate too much waste. 

Start by cutting the 4x4x8 into the correct length using a circular saw, four pieces at 12” long for the 12” walls or four pieces at 16” long for the 16” length. Many circular saws won’t cut all the way through a 4x4 post, so you will have to mark around to the opposite side to make your cuts on the opposite side line up properly.  If you don’t have a circular saw, you can also use a handsaw, it will just take some muscle.

Now measure your boards to make sure each cut will give you a 4’ section.  Make all your cuts at once so that everything will be ready to assemble. You will need to cut two pieces of 4’ for each side. You now have everything cut to the right lengths to get started on building your raised beds.

Fasten the 2x6 Juniper boards to the posts using the timber screws (which are very rust-resistant). You will need to be careful to position the screw holes so they won’t hit each other coming in from a right angle. To do this, you will alternate our holes at high and low points on the post at each corner for each 2x6. 

Since our screws are at least 3-1/2” long, we will take our drill bit that is the diameter of the SHANK of the screw and drill the FULL depth of the length of the screw. This is the PILOT hole; this is the hole that the screw threads bite into.  Then follow this with the larger drill bit (sized to the diameter of the screw threads) JUST to the thickness of our outside board. This is the CLEARANCE hole; this allows you to easily pass the screw through the first board and allows ALL of the attaching power of the threads to be applied to the second board (your upright post).
            
Screw the first board to a 4x4 post making sure it is flush with the bottom. Repeat this at the opposite end of the board with a second post.  Secure the second row in the same manner.  Now you are ready for the next side. As explained earlier, stagger the attachment holes on the right angle of the post and screw the bottom tier to the post and repeat with the second tier. 

Now you are ready to set the 90 degree angles of the two sides.  This can be done using a carpenter’s square, or, if you only have a measuring tape, the 3-4-5 method (SEE ILLUSTRATION).  It is important to make sure each corner makes a 90 degree angle or your raised bed will not be square. You just have to repeat these steps for the two remaining sides, making sure each board is secured to the post with two timber screws.

When you’re finished, get someone to help you position it where you want the bed, making sure it gets plenty of sun.  I recommend laying steel mesh (also called ”hardware cloth”) followed by landscaping cloth on top before you add the soil.  This allows for good drainage while keeping gophers and other unwanted critters out. Pick a screen size that is less than 1” squares; DO NOT use window screen. If you want to put a layer of gravel before the soil goes in, this will further aid drainage, also. I recommend 3/4–minus gravel (can be purchased in bags) about 2” deep.

Basically, you’re done. But if you want to add a sitting/tool ledge around the top, remember to figure in extra 2x6s for that; these can also be added later if you decide.

There you have it! Now it’s time to fill it up with your favorite mix of garden soil and other soil amendments and you’ll be ready to plant your healthy garden.  Your new Restoration Juniper raised bed will give you many years of gardening enjoyment and without the introduction of any harsh chemicals from the lumber.