Tuesday, November 5, 2013

Building Raised Beds for the Vegetable Garden

When we moved into our new house, I knew right away that I wasn't going to be able to have the same type of vegetable garden I had at our previous home - one that was low to the ground and relied heavily on the natural soil in our backyard.  Here, we have little to no top soil.  Dig a couple inches down and you'll find plenty of fist-sized rocks and heavily compacted dull-brown subsoil.  The good news is that there's not a slug, grub, vole or other soil-bound pest to be found anywhere near this area.   The bad news is that there are no worms or other beneficial insects either.  My only real option in this case was to build my garden up.

There are definite pros and cons to having a tall raised bed vegetable garden. In this type of garden, you can import high-quality soil and have greater control over the growing conditions of your plants.  In addition, I think raised bed gardens are generally easier to weed and maintain.  The major con, however, is the higher start-up costs.  Each of my 8' x 4' x 20" beds will cost me about $70 - $80 in building materials and that's not including soil.  Times that by 8 or 9 beds and it can get quite expensive.  Tall raised bed gardens also require more water, which is why I'll have to seriously consider installing a more efficient drip irrigation system next year. 

Building the beds themselves was actually quite simple.  In this case, I used 2" x 10" x 8' boards of Douglas fir,  a total of 6 for each bed.  For the corners, I used 2 feet lengths of 4 x 4's and 3 1/2 inch wood screws.  The extra 4 inches at the bottoms of each corner act as footings, though I seriously doubt these beds (which weigh a ton) would be going anywhere even without them.

I also considered using pressure treated wood but in the end decided against it.  Though the chemicals used nowadays in the pressure treating process are much less toxic than the ones used a decade or two ago, I figured the 7 to 10 years of life I'll get out of these untreated boards won't have too much impact on my wallet in the long run.

I also installed 1" PVC pipping in the corners and middle of each bed using medal straps at the top and 2 1/2" screws at the bottom.  These will allow me to install 3/4" PVC or metal hoops easily to each bed if needed.  I can also use them to hold up simple trellises. 

Once the beds were installed, I added a thick layer of partially composted grass clippings from this past summer and dried leaves.  Not only will these break down during the winter and help feed the plants next year, but they'll also help to cut down on the amount of soil I'll have to add to each bed.  (Another reason why fall is a great time to start a garden.) The soil I'm using is from a local company and is a mix of loam, vegetative compost and horse manure. 

And here are the finished beds.  Two down and many more to go. 

10 comments:

  1. I'm happy to see just how deep you made the beds. I don't know how anyone grows a decent garden with only 4-6" of good soil. I kind of miss my boxed in beds (I'm down to three, as the wood rots it's removed). I did find they heat up very quickly here, resulting in some burned plants. However, the yields I got from them were much greater than what I'm getting in the wide row planting method I'm using now. They were also much easier to care for, and easier on the back!

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    1. I remember all of the raised beds you used to have, Gran. But you're garden looks just as lovely without them!

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  2. Your beds are beautiful, I think you'll be really happy with them. I have a couple of observations based on my own experience with tall raised beds on top of crummy soil. First, you will be amazed at what moles and voles can tunnel through, you might consider putting hardware cloth or small mesh chicken wire at the bottoms of the beds. Second, all that lovely new soil is going to settle down quite a bit. I filled my beds to the brim and they settled down to about the level that you have in your bed now.

    You know the flip side to being hard to water is not having to worry about over watering. :)

    I like your idea of putting the PVC pipes to support the hoops. I've been toying with the idea of doing something like that so that I can enclose a bed and get a jump on the summer crops.

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    1. We spotted a field mouse the other day! I blamed you, Michelle! I was planning on installing the hardware cloth but couldn't find any this time of year in 4 ft width. I will definitely be doing this to the other beds next year.

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  3. Beautiful deep beds, a drip system makes life a lot easier, can't wait to see the beds fill with veggies.

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  4. Lovely beds. Another flaw to raised beds is when you want to grow vertically, you can't reach as high. I notice it with just a 6" raised bed. I still like them and it is a good solution to really bad top soil.

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    1. I agree Daphne. It will be tricky with tomatoes and the amount of ocean wind that we get here. I can see a number of toppled plants.

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  5. Love your new beds. I did the same thing. I have moved to Florida near the gulf and only have sand so my garden is 20 inch depth grow beds also. They are doing wonderfully and seem to be deep enough for everything. I may have to use your PVC pipe idea. That would make some things easier.

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  6. Wow! Can't wait to see those beds filled with your favourite veggies....good luck & happy gardening! :)

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