Wide Row Planting and Trench Composting
in the Vegetable Garden
By Ginny Stibolt (Listen to my podcast on composting
Composting is that magical process in which garden waste, water
weeds, kitchen scraps, dryer lint and other organic materials are
turned into a dark, nutrient-rich soil amendment that looks nothing
like the original materials. Microbes, those unseen soil inhabitants
including bacteria and fungi, do most of the work but worms and
other larger critters play roles as well.
Kitchen scraps enrich the soil in your garden beds--in
situ composting. >>
I wrote an article Composting for Your Garden in 2006,
which continues to be one of my most visited articles. I also included
even more details about various ways to compost in Chapter Three
of my book. Since 2004, when we moved to northern Florida, we've
produced many huge piles of wonderful, rich compost. Our successful
vegetable crops over the years make the case for using compost alone
to fertilize crop plants.
In previous articles I've mentioned in broad terms that trench composting
can work in vegetable gardens, but now let's fill in some details.
The wide row planting arrangement that I use in most of my vegetable
beds is perfect for trench composting.
Wide row planting: the details
Wide row planting is one of the intensive growing
arrangements used to cram as much growing area in small spaces as
possible. Square-foot gardening is another popular intensive
arrangements where you lay down a one-foot grid over your garden and plant
crops at just the right distance from each other within each foot.
Wide row planting is less rigid--rows can be 6 to 20-inches wide with the plants spaced so they are just
the right distance apart. In between the rows is a 6-inch deep
trench that is 4 to 20-inches wide depending upon how much room the
crop growing in the adjacent rows will need. The rows are short (No more
than five feet long), so you can reach into the growing area without
stepping on the soil.
The trenches between the rows allow for water drainage
during heavy rainstorms and provide a little more space between the crops.
Trenches should be heavily mulched with easy-to-remove materials such as
pine needles, straw or dead leaves. Mulches such as sawdust or wood
chips don't work well for mulches where there is so much activity--they
would be too hard to rake away. I fill my trenches with pine
needles as mulch right up to the level of the planting surface to keep the
weeds down. There are lots of pine needles in our neighborhood, so
this is a free mulch for me.
<< This wide row planting has a 20-inch row on the
left with sweet onions spaced four inches apart and a 10-inch row with
broccoli plants alternating down the row. In between, the six-inch wide
trench is filled with pine needles. When the broccoli plants fill in
you won't be able to see the trench from this vantage point.
Trench Composting: What, when and
The term is descriptive of the process--you compost in a
trench. It is most often used by small vegetable gardeners within their
planting spaces, but well before any crop roots have reached the area,
because you don't want to damage the roots. So trench composting is
only useful when the crops are still small or as you're planting the
crops. First remove the mulch, dig the trench another 4 or 5 inches deeper,
lay in a 3-inch layer of kitchen scraps (no meat, bones or oils), cover it with one
or two inches of soil, and then replace the mulch. You are not limited to
kitchen scraps, you could also use the remnants of your crops (as long as
they are not diseased), grass
clippings or other green compost materials.
Recently I transitioned between our cool-weather
and warm-weather crops--from lettuces and bunching onions to okra and
peppers in one area of the garden. The onions and the lettuces had been
arranged into three rows with narrow trenches. After I'd harvested the
last of the onions and pulled up the stubs of the lettuce plants, I raked away the pine needle
mulch (for reuse) and then dug in some finished compost (from my big compost
pile) to enrich the soil before planting the next crops. I then
rearranged the area into two rows (instead of three), because the new crops will take more
room. The trench between the rows is wider, too.
I dug deeper between my new rows, laid in my kitchen scraps and covered them with soil,
gently tamped it down, and covered it all with pine needles. By the
time these new crops have roots long enough to reach the kitchen waste
deposit, it will be dark, rich compost filled with with macronutrients, nitrogen (N), potassium (K), and Phosphorus (P) and
particularly calcium, because of the eggshells.
In this photo, the trowel is lying over the trench, which
is mulched with pine needles, in the area where I'd buried the scraps shown in the lead photo. This
trench between the rows is about 10 inches wide. I planted two okra seeds in
each of the five holes in the wide row to the right of this photo. The spacing between
plants is supposed to be 12 inches. Note
on the circles between where I planted the seeds: they are shallow basins to make it easy to hand water the
okra so the water stays put and doesn't roll off the hill. Then I
planted several nasturtiums below the okra and next to the walkway. Nasturtiums
are in my edible garden for two reasons; 1) they'll attract pollinators
and 2) they're edible and their slightly peppery flowers and leaves will grace many
of our summer salads. And oh yes, they are beautiful!
I planted three bell pepper plants in other row--to the
left of the trowel. They have
cardboard collars around them to keep the cutworms at bay and soon I'll
place three tomato cages over them to keep them upright. There is
no trench between the pepper row and the parsley row. By the time the
peppers get serious about growing in the summer heat, the parsley will be
gone. I'll just mulch over the parsley row after their final
harvest. I will not dig a new trench at that time because the pepper roots
will be in the area and I'll also just cut off the parsley rather than
pull it out so I don't disturb the peppers. So now this part of my
garden is arranged for the summer and will be rearranged yet again in late
fall to make way for the new winter crops, but not lettuce and
onions--I'll plant sugar snap peas and carrots to complete my crop
Composting: a gardener's best tool
If you haven't done any composting yet, read Composting for
Your Garden, and you should be ready to try some trench
composting, too. You'll reap more and better-looking crops. I know
you'll love eating from your garden the way we do. Both you and your
wallet will be in better shape.