July 2020 - 18

GROWER'S POSTCARD
Raised beds, when done correctly, boost production
SAM OSCHWALD
TILTON
rcvcfarm@gmail.com
run a Perfecta to pull mounds down
and crumble the soil (it has rolling
baskets mounted on the side to keep
moving soil from the tire tracks into
the bed - Photo 2); final pass with a
Buckeye bedshaper.
Jean-Paul emphasized that when
Greetings from the height of summer,
dear reader. Do you have your cold drink
of choice out in the field - iced tea, iced
water, a switzel, cold soda, lemonade?
Whatever it is, I hope you have plenty of
it. Here on the Wisconsin shore of Lake
Michigan it has been a cool spring into
early summer.
The planting season started with a
spate of wet weather. And as I watched
my friends try to get seeds and plants
in the soil between rains, I got to
thinking about raised beds, and that is
the subject of this postcard - a dispatch
from the bone-dry dominion of a
raised-bed.
I commonly hear these general
thoughts on raised beds: on the upside
they offer good moisture control, ease
of harvest and allow early planting;
on the downside they are harder to
weed, dry out faster, require more
horsepower to form and reduce the
plantable space when compared to flatground
planting.
I know a lot of growers using raised
beds, but few who feel like they are
doing it well. I had to go straight to the
source to get some answers - Jean-Paul
Courtens was trained as a farmer in
his native Netherlands and has farmed
vegetables in New York for decades.
I had the pleasure of meeting him
in-person years ago when he came to
speak at the first Midwest Mechanical
Weed Control Field Day, and have
Photo 1: A disc bedder, with markers
raised. Photos: Jean-Paul Courtens
learned from many of his talks posted
online since then. Jean-Paul was nice
enough to take some time speaking to
the Grower's Postcard about his use of
raised beds.
First is the forming. For his large-scale
vegetables Jean-Paul used blocks of eight
beds with drive lanes in between. The
drive lanes never move, so the eight beds
between them must be perfectly spaced
to fit: just 1 inch off on each raised-bed
would add up to 8 inches that would
either eat into the next drive lane or leave
a strip of unused earth between the last
bed and the drive lane.
To shape and space the beds with
the needed precision Jean-Paul used
a disc bedder (Photo 1). This is a tool
often used in Texas and the West to
form narrower 36-inch beds for furrow
irrigation. But Jean-Paul spoke with
the manufacturer to make a bedder for
primary bed-shaping, working three
beds at a time and marking the next
pass. With this tool his bed-forming
procedure looked like this - mow a
cover crop; incorporate residue and
loosen the soil with a chisel plow;
make two passes with the disc bedder
to form mounds, rough-in tire tracks
and bury the cover crop; let sit for one
to two weeks for residue to decompose;
making the final bed-shaping pass it is
crucial that the press-pan of the shaper
compress the bed firmly - this is so
that all weed seeds have good seedsoil
contact and will be encouraged
to germinate. " If you use a rototiller
it will make you think you have clean
beds, but the weeds do not have good
seed-soil contact, and will germinate
later, once your crop is growing. "
If you form a tight, flat bed-top, then
depth-control is not as important and
a basket weeder can do a good job.
Keeping the bed shoulders clean can
be a challenge. The banana knives
commonly used out West constantly
shave the shoulders away, whittling
down your bed. I think Lilliston rolling
cultivators set to pull soil up are a best
bet for cultivating the shoulders while
maintaining their shape.
An interesting option are guidewheels
attached to the planter and
cultivator frame that hug the shoulders
to keep your tools locked on the row,
reducing the manual steering needed.
But for these to work the beds need to
maintain their shape, which can be hard
in the Midwest and East where heavy
rains can change the bed shape.
One great practice with raised-beds
Photo 2: Modified Perfecta to work cover
crops into roughed bed tops and bring
soil from tire tracks up into bed.
You can see how Jean-Paul is keeping
an eye to detail in his tillage. And it
doesn't stop there. He lets the newly
formed beds rest long enough for the
first flush of weeds to germinate. Then to
kill these weeds before planting he uses
an implement whose tillage depth he
can control exactly (Photo 3). This final
tillage could be combined with planting
into a single pass by mounting the
seedbed maker on the front of the tractor
and the seeder on the rear. He tills to the
exact depth that he will place his seed or
transplant. This is the technique known
as " planting to moisture. "
" Till only as deep as you will plant - so
that your seed is in touch with the firmer
soil deeper down and the moisture
that firmed soil provides through
capillary action. The top layer of soil
will remain loose and will not conduct
water to the weed seeds contained in it.
Then the soil-moisture is germinating
your seeds. When you irrigate you're
favoring not just your own seeds, but
every seed in the seedbank. If you put
your seeds in the ground and irrigate,
it's basically a free for all, and guess
who's going to win! "
Raised beds do require reducing
the amount of plantable surface. For
example, Jean-Paul's tires are 72 inches
on center, but his bed-tops are 54
inches, with one, two or three crop
rows 18 inches apart and the outside
rows 9 inches from the bed shoulder.
People with tires 60 inches apart could
have bed-tops of 40 inches and use
three, 15-inch rows.
It is true that the biggest downside
of raised beds is weed control - this is
because the normal parallel units that
most people use (which allow depthcontrol)
don't function well when the
gauge-wheels run on the bed shoulders.
18 | VegetableGrowersNews.com
Photo 3: Front-mounted seedbed maker
allowing for precise depth-control of final
tillage pass.
It is easy to suggest that growers get a
lot of equipment to do the job " right " -
but we can't let the perfect be the enemy
of the good, and many growers are not
at the scale to form multiple beds at once
or don't have the money. After many
years of growing extensively, Jean-Paul
now manages a few acres of seed garlic.
He described the minimum equipment
needed to successfully form and manage
raised beds - a chisel-plow to turn under
cover crops and loosen soil (preferably
after being mowed), a rotary tiller to make
a tilth and freshen beds, and some type of
bedshaper, would be enough. Narrower
tires, such as 13-6's would leave you more
space in which to make your beds.
If you want to learn more, Buckeye
tractor company has a great handbook
on its website, and for larger scale
considerations look up Bulletin 4646:
Raised Bed Farm in Western Australia.
Until next time I remain yours,
Sam VGN
is to form some and keep them 'in the
bank' so that during periods of wet
soil you always have some drier raised
beds that can be planted into. I know
a grower who had trouble finding dry
land to plant garlic into in the fall. As
a solution, in October, he removes
the plastic from the raised beds where
squash grew in the summer, revealing
dry soil ready for garlic planting. Other
growers will form raised-beds in the
fall that will drain more quickly than
flat ground in the spring and yield a dry
seedbed earlier. Other growers will form
raised-beds and cover them with tarps
to prevent weed growth, uncovering
them when they are ready to plant.
http://www.VegetableGrowersNews.com
July 2020

Table of Contents for the Digital Edition of July 2020
