Zach
Lester has an extensive history of growing nearly every kind of vegetable, both
outside and indoors. After successfully operating his own Tree and Leaf Farm in
Fauquier County, VA, Lester has taken his talent to Potomac Vegetable Farms.
Hui
Newcomb and her husband started the 100-acre Potomac Vegetable Farms (PVF) over
50 years ago. Today, Hui and her daughter Hana Newcomb, along with Carrie
Nemec, oversee farm operations on acreage in both Purcellville and Vienna, VA.
Lester,
who has more than 20 years of experience as a grower, arrived at PVF with
extensive knowledge about using high tunnels effectively for growing in all
seasons. PVF uses ecoganic practices, which include on-farm composting to build
nutrient-dense soil.
“Wherever
I land, every ecos is different,” said Lester, adding that PVF is the sixth
farm he’s been on. “The soil, weather patterns and dew point are all factors.
The first year is a study. Knowledge quantified at one farm might be a
different situation at the next.”
For
Lester, last year was a time of planning, planting and settling into his role
at PVF. He said growing outdoors last winter was difficult, and noted extreme
variations over the season, high wind chill and voles as some of the
challenges.
Lester said
there are positive aspects of growing produce through winter, including
leveling the workload throughout the year rather than concentrating the load
during the typical six month growing season. Year-round growing helps
distribute staff time, energy and labor, but winter challenges led to some
changes.
“We
decided to downsize our operation,” said Lester. “Our CSA ends in December, and
we take January, February and March off.” He said the decision was primarily
due to staffing issues and lessons learned last year, including losing about 50
to 60 percent of the harvest.
After
seeing the problems caused by both excessive rain and snow melt, Lester is considering
measures that will limit snow accumulation and channel water away from the farm’s
numerous high tunnels.
“The
question is how we’re going to keep excess water from both rain and snow melt
away from the tunnels,” said Lester. “It’s nice to be inside the tunnel after a
snow. It’s warm in there, and are there are living crops, but we have to get
rid of the snow outside the tunnel because it’s going to cause flooding.” He said
a snow blower helps eliminate some of the snow, but he is working toward dedicated
drainage to move water away from between the tunnels.
“The rest
of PVF is large fields with big rotations,” said Lester. “We can drive all over
the place, but by winter, we don’t want to do that. We just want to go into the
tunnel or to the row cover, then walk to the shed without having to drive
through a muddy field. We need drain tile and an apron so water coming from
above can continue to flow downward.”
Lester said
ventilation is critical for high tunnel crops no matter what time of year
they’re used. “Roll-up sides are easier to ventilate, but they’re really
costly,” he said. “With roll-up sides, I could open the north side just a
little and open the south side much higher for ventilation.”
Rather
than spending money on roll-up sides, Lester concentrated on end-wall ventilation.
This includes folding doors designed to open completely, providing good air
flow any time of year. When temperatures are in the 40s, Lester opens the
tunnel end doors and closes them by early afternoon. On cloudy, rainy days, he
still opens the doors for air circulation, and on windy days, just one door is
open.
“If it
isn’t too windy but it’s cold outside, I’ll open up because crops are covered
with a cloche,” said Lester. “We want the air in there. Open end-walls require
sturdy construction with solid sill boards and frames that keep the entire
structure stable.”
Several
caterpillar tunnels on the farm are used for winter growing. “I had some
smaller, shorter ones,” said Lester. “Some are too tall, and if there’s a lot
of snow, even with a center truss, snow gathers on them and makes the tunnel
more vulnerable to wind. I have to work really hard to keep the snow off to
keep the tunnel up.” Although he uses some caterpillar tunnels, his experience with
growing in several locations confirms his belief that winter growing is more
successful in high tunnels.
Lester did
some shallow tillage in tunnels last year, and will probably continue the
practice. “I was going to be asking more from the soil in the tunnels than from
a field,” he said. “We ripped the soil to about 18 inches before the tunnels
were put up here, and I used a rotary spader that goes down to 12 inches.”
Ongoing tillage will be closer to four inches as Lester concentrates on
improving soil tilth.
After experimenting
with various mulches and landscape fabric, Lester has seen benefits and
disadvantages. “I’m trying to keep any kind of cover off as long as possible
because of the vole population,” he said. “We’ve used vole traps, which aren’t
very effective and smell really bad. We’re experimenting with buckets of water …
but we’ve had so much water that the buckets pop out of the ground.” Lester
plans to discontinue growing root crops in tunnels over winter because losses
to voles are too high.
Weed management
is an ongoing issue, and Lester said flame weeding is a good option. “We wet
all the beds and create a lot of steam,” he said. “That seems to help, but
there’s still work to be done.” Lester allows weeds in the tunnels get a little
bigger so he can weed by hand and remove them. However, sometimes embedded root
masses result in weeds returning.
Drip
irrigation helps seedlings get a good start in tunnels. “I’m doing a lot of
succession plantings,” said Lester. “When everything is set, I use some overhead
irrigation. The head line outside might be frozen, but I can set up a center
row of wobblers.”
After
seeing extensive hail damage to the high tunnel covers last season, Lester is
considering an additional layer of plastic on the tops of high tunnels to provide
another layer of insulation. In addition to managing water runoff, Lester’s
long term plans for PVF include electricity for the propagation house, which
would also provide electricity to run fans in the high tunnels.
Visit Potomac Vegetable Farms online at www.PotomacVegetableFarms.com.
