A while back, a neighbor purchased some special plastic boxes for
container gardening. We looked at what she had, and the great
vegetables that she was able to produce in them, and thought that it
was an idea that could work for us. However, the boxes she had were
large enough to be unwieldy, and expensive.
We figured out a cheaper alternative that looks like it is going to
work great. Rubbermaid 18 gallon storage totes are a size that can be
easily moved (they even have handles) and have been on sale at Lo--s
for about $6 each.
To convert them to container gardening, I drill a 1/2" hole in one
end, about 4" up from the bottom. This acts as a weep hole for
over-watering and heavy rain. The bottom four inches contain nothing
but water and some 5" tall supports I made out of 3" PVC piping.
The supports hold up a hardware cloth grid, which is in turn covered
with a layer of newspaper and about 4" to 6" of soil and potting mix.
The grid is the hardest part of the construction. I used a bandsaw (a
hand jigsaw will do) to cut a section of plywood to fit at the 5"
level from the bottom of the tub (at the top of the 3" PVC pipe
supports). This plywood was then used as a bending and forming
pattern to make the hardware cloth grids.
Using a heavy pair of gloves and tin snips to cut the hardware cloth,
I cut a section of hardware cloth about 1/2 the width of a roll of the
cloth, and about 18" wide. I then fold that around the pattern and
remove the pattern. The folding of the edges gives support for the
wire mesh, which would otherwise flop down under the weight of the
soil. Two opposing corners get folded again at 45 degree angles. One
of them makes space for a 2" pvc pipe used to add water to the water
in the bottom (or to siphon water off before moving the box), and one
makes space for a tightly rolled newspaper, which acts as a wick.
The top of the box can be covered with screening to keep out insects,
or hardware cloth to keep out squirrels, or by the original tote
covers for more protection. Ideally, the boxes would sit in a screen
The concept is that the roots can penetrate the soil and newspaper to
get to drink out of the well of water in the bottom, while the soil
remains moist but never wet, because it sits above the water. A heavy
rain just flushes through and out the weep hole. In dry periods, the
water in the well keeps the plants growing without getting their
leaves wet and susceptible to fungus and rusts.
The 2" pipe also allows the water in the bottom to evaporate more
freely on hot days, which helps prevent cooking the plants in the
containers. We selected a silver colored container for the same
reason, although black containers might work further north.
Since the boxes are small enough for a single person to move, they can
be moved for different light, or indoors if a hurricane (or frost in
colder climates) threatens.
Another reason that we use the boxes is that Florida soil contains
nematodes which will stunt the growth of plants placed directly in the
ground. We've had some spectacular starts that suddenly failed due to
pests in the ground.
I mention these boxes now, because they can also be great for getting
an early start gardening lettuce, spinach and other cold weather
crops. Plop an aquarium heater in the bottom well, use the cover or
some polyethylene on cold nights, and people in the north can start
growing some fresh greens now. The sides of the boxes are high enough
to break the cold winds and offer protection.
I had the piping and hardware cloth on hand, and made a half dozen
boxes for the price of one of the fancy boxes our neighbor has. DW
will be harvesting mescaline mix for salad today. :-)