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Raised Beds 101:
We started off removing about 150 square feet of lawn to put in four 4' x 8' raised beds. The first three were done with 2 x 10's of pressure treated wood. Except for that "small arsenic problem", they are still doing fine many years later. The fourth, we made out of regular pine 2 x 10's. Alas, it only lasted about three years before becoming so rotted, that it was not only ugly, but ineffective. (Note: It turns out that using "regular" wood in raised beds that get watered regularly produces an optimal environment for termites, definitely NOT something you want too near your house!) So it was removed, and the hunt for alternatives began...
Over the last few years, Kristen had also been "complaining" about how the 4' x 8' x 10" raised beds forced her to spend a lot of time on her knees bent over. So, the alternatives also needed to be taller, and possibly smaller. We had seen on some gardening show a woman's garden made up of nothing but 4' x 4' raised beds, and had commented about how easy they would be to care for...
Now about a year ago, one of our local gardening celebrities, Ciscoe Morris, mentioned using plastic lumber for raised beds...
So, the criteria for non-wood raised beds are:
We immediately decided on Plastic, mostly because of the long life span and arsenic free nature of it, but the question then was what kind of plastic?
(It is interesting that we never even considered brick, maybe because brick always seemed so rough and whenever you brushed up against it, it would either scratch you or snag you clothes...)
It turns out that plastic lumber, while having both good tensile and compression strength, does not have good resistance to bowing.
This means that for longer spans, the "lumber" would need to be very thick or have additional bracing. And, to support leaning and sitting on it, the "lumber" would need to be either: very thick, or be shaped into a 'T' beam (either as a single piece or as two pieces so tightly connected that they would "act" as a single piece). If the 'T' beam approach is taken, then the "top" of the raised beds would "overhang" into the work area. This seemed less than desirable.
After some research, we discovered that plastic "lumber" is actually rather expensive!
there were four options:
By this time we had settled on having "many" 4' by 4' raised beds (very easy to work with).
With this size in mind, and our criteria from above, the options were evaluated:
Well, as should be obvious by now, we choose option 4, SmallRock Design's Plastic "rock" walls, you can check out our project here.
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