Seasonal high tunnels have lots of benefits, especially in a
state like Alaska where cold weather leaves a short growing
season. They are incredible garden heaters, season extenders and
profit generating machines for Alaska growers.
Seasonal high tunnels allow farmers like Alex and Kelly Strawn
in Lazy Mountain, part of Alaska’s Matanuska Valley, to save on
energy costs, control where to put water and fertilizer and grow
more variety of vegetables for a longer period of time.
Because of these benefits, USDA’s Natural Resources Conservation
Service (NRCS) provides assistance to farmers wanting to build a
high tunnel.
While high tunnels may look like greenhouses, growers manage
them quite differently.
In high tunnels, plants are grown directly in the ground. High
tunnels don’t use heaters and lights. Opening and closing the
high tunnel regulates the sun’s heat.
High tunnels also control the rain.
In Alaska, rains often come during the best time to harvest, and
high tunnels serve as an umbrella, minimizing rain damage to
valuable crops.
Their warmth enables the production of warm-season crops such as
peppers, tomatoes, cucumbers and melons, which do not grow well
outdoors in Alaska.
“These warm-season crops are customer favorites and bring
premium prices at the farmer’s market,” Kelly Strawn said.
Last year, the Strawns grew three varieties of peppers, sweet
corn and artichokes in their high tunnel.
High tunnels extend the growing season by allowing the grower to
plant several weeks earlier in the spring and harvest well
beyond the traditional time when plants are typically killed by
frost.
Farmers growing leafy greens and other fast-growing produce have
enough time to grow two crops, doubling their yields. The
lengthened season of the high tunnel also enables Alaska growers
to raise some of the more flavorful, mid-season varieties that
will not ordinarily mature in Alaska’s short season.
The Strawns were some of the first people in the
Matanuska-Susitna Valley to build a high tunnel with the help of
NRCS.
As high tunnel veterans now, the Strawns have some advice.
First, make sure the high tunnel can be ventilated. Tunnels with
automatic ventilation are best, they said.
Also, make sure to space out plants to allow for air movement.
This reduces humidity and stagnant air, which can increase
fungal molds on plants.
The Strawns also recommend intercropping plant species, meaning
mix the plants in an area. An example is intercropping tomatoes
with certain plants because tomatoes produce a volatile alkaloid
called solanine that acts as a natural pesticide.
They also recommend growers to take advantage of their watering
system.
The Strawns mounted their water tank inside the high tunnel to
serve as a “heat sink,” which increases heat at night. In
addition, they mounded soil in raised beds and buried their
irrigation to keep in heat during cooler times.
To learn more about NRCS assistance for seasonal high tunnels,
click here. |
