Pallet Growing Boxes

Growing sweet potatoes in a pallet box. 

Beans growing in a pallet box. 

Some areas of Hawaii simply don't have enough dirt to grow much of anything except drought resistant scrubby grass and brush. While my main farm has nice soil, the warmer, lower acre has little. The land is mostly lava. So in order to use the land for growing, I had to come up with a solution.

The first thing people (not from my area) suggested was hydroponics. Well, that sounds good until you consider that the area is quite dry and does not have a source of water. All water has to be trucked in. Next, most hydroponic systems require electricity. This property has no electric. Ah, strike one and strike two! And since I only visit the property once a week, a hydroponic system isn't realistic. Strike three!

In keeping with my philosophy of being fairly self reliant and low input (a.k.a cheap), I concluded that some sort of container beds might do the job. I've seen nice beds made out of 2x12 lumber, others made out of concrete board. Both very pretty and effective. Both cost money. I wanted a better solution. Last year I attended a lecture about recycling wood pallets. Although the lecturer didn't mention boxes like these, it got me to thinking. I wrote down my requirements, gave it more thought, then picked up some pallets to experiment with.

Requirements:
   Quick and easy to make.
   Cheap to make.
   Easy to disassemble.
   Capable of holding soil.
   Easy to work with.

What I came up with:
   Four pallets-- trimmed to 36" length
   Three nailed together for the back and two sides, set up so that the slats run horizontally.
   Height 36" - easy for me to work with
   Fourth side wired to the sides (top and bottom) so that it can be easily disconnected.
   Inside covered with discarded tarps cut to size. I also have success using used heavy duty trash bags, old feed bags, etc. I just use a staple gun to tack the material in place. The soil does most of the work.

I run the slats horizontally because as I am filling the boxes I like to climb in and and tramp the material down. This way I don't have to keep a ladder handy.

These boxes cost me only the cost of the nails and the wire. The pallets are free. I get people to give me worn out tarps, feed bags, etc.

Since I don't have much in the way of soil to fill the boxes, I had to be creative in this department too. So I layer it like a layered compost pile. Ah-ha, now you may have guessed why I want to be able to open the boxes up. When whatever I was growing is done, I open the box and harvest the compost. I mix it up with the rototiller then use the material when filling other boxes. It gets recycled, creating more "soil".

The bottom layer is cardboard a couple of inches thick. I use this in order to keep the guinea grass from growing up through the box. That grass is incredible. It ruined the first few boxes I made by growing three feet through the compost layers then taking over the box. So, I've defeated it with the cardboard layer. The rest of the box is filled with repeated layers of lawnmower clippings, horse manure, discarded weeds, chicken pen litter, old mulch, and sprinklings of soil. I also add a little wood ash, biochar, burned coral, homemade bonemeal, and urine. Plus plenty of water, enough to keep it moist but not soaking. After the material has sit for a few weeks it's time to tramp it down and add more. Another tramping a couple of weeks later, top it off one more time then cover with a couple of inches of good soil.

When I plant the box, the  box is filled to the top. By the time the crop is ready to harvest, the soil level is down about one foot or more. That actually is a benefit because the sides of the box helps protect the crop from the tradewinds.

So far these boxes are working out great. I erect them so that there is an aislesway between them that I can take a wheelbarrow down. At first I thought that was a waste of space, but it turned out to be rather handy. It makes getting water to the boxes easier, re-working the boxes pleasurable, and gives some of the crops space to sprawl. The sweet potato vines hang down the sides of the boxes and actually look quite nice.