Advice for growing year-round

Rowe;s Garden "hoop house" - photo courtesy Barbara Rowe

In the wake of the recent E. coli scare in the Pacific Northwest, Lebanon resident Barbara Rowe, owner of Rowe’s Garden, hopes to educate locals on growing their own produce year-round.

“When you’re growing it yourself, you know what’s in your food,” Rowe said.

She believes in farm-to-table operations, and is a distributer at local farmers markets and to Willamette Valley businesses. Her clients include Lebanon’s 1847 Bar & Grill, Albany’s Ochoa Cheese Factory, and Corvallis’ Market of Choice.

Although her operation is on a larger scale than many home gardeners, she knows with the right setup, growing your own crop is possible for up to 10 months a year. She understands seasonal changes can constrict gardeners in the Willamette Valley, and her solution is the hoop house—a low tech, low cost growing space.

Hoop houses

“What you’re doing in a hoop house is controlling the water and the wind,” Rowe said.

From her observations, the wind-factor can change the external temperature for a plant by eight to 10 degrees. In the Willamette Valley, that can make a significant difference in how long a plant will produce.

Their stretched plastic cover, often in a tube-like shape, held up by the “hoops” that support them is how they got their name. What makes the hoop house unique is its plastic cover’s ability to roll up and down for needed heating and cooling.

“You literally roll it up so it comes up 3-4 feet on each side so you have airflow coming from one side to another,” she said. “During the night you can roll them down for warmth.”

Hoop houses require few supplemental systems such as fans and heaters that many greenhouses require. With the initial investment for the kit to get started, hoop houses will help keep overall operating costs down.

Although the hoop house may require more attention than an outdoor garden, they increase both the production of plants and their longevity. Because the hoop house protects the ground soil in which plants are grown, there is less stress on the plants resulting in a more plentiful production.

“The end of my summer has not ended yet. We will have tomatoes through Thanksgiving,” she said.

Rowe recommends two hoop house suppliers that have served her well: Oregon Valley Greenhouses and OBC Northwest.

Getting started

In Rowe’s opinion, controlling water is one of the most important elements in a successful hoop house, and will affect the overall happiness of plants. She suggests that one of the first things done in a hoop house is installing a timed watering system.

A watering system ensures plants receive regular water, and allows you peace of mind if a busy day keeps you from tending the garden. Overwatering can cause as much damage as under watering, which is another reason Rowe recommends a controlled watering system.

“A filter setup at the water source will keep sand out of the system that will clog the timer,” she cautions.

For a good selection of filters and watering systems, Rowe recommends Home Depot or Dripworks in California.

She also found through trial and error that much of the local well water has iron in it, which can damage systems and drippers. City water, she found, contains less iron. She suggests to keep this in mind when selecting a system.

Controlling the climate

As winter approaches light becomes more scarce, and during the shortest days of the year plants receive  about seven hours of sunlight. That, combined with cold weather, is the reason winter production comes to a halt. There are, however, steps you can take to help protect your plants from low temperatures in a hoop house.

“Row cover cloth will give you 3-4 degrees of protection from frost,” Rowe said.

The cloth is essentially a blanket for your plants, protecting roots by trapping heat and shielding them from chilled winds. Increasing the temperature by a few degrees during the winter can result in a longer growing season.

Rowe recommends buying row cover cloth from Johnny’s Selected Seeds in Maine.

Growing the crop

A benefit to the controlled environment in a hoop house, especially during the winter, is combating natural phenomena that occurs when plants are exposed outdoors.

“Any of your root crops that grow in the winter you can grow in or out, but get bigger in a hoop house,” Rowe said. “Whatever is happening outside, your hoop house is growing for you.”

Root rot is common in bulbous winter crops such as onions. In a hoop house, by controlling the groundwater and eliminating the flood-factor, root rot should be of little concern, according to Rowe. Protecting leaves from rain or snow also keeps leafy winter greens in good condition for longer.

“I think that with our changing climate it’s especially important to avail ourselves of theses things,” she said.

By not rolling up the sides on a stormy or foggy day, the hoop house will maintain a consistent temperature. Solar heat collected by the transparent plastic covering will provide warmth, even on a cold day. Extreme cold can kill plants overnight without any protection, she cautions.

Rowe’s crop recommendations for winter produce are: kale, swiss chard, leeks, lettuce, onions, garlic and shallots. She has had success growing each of them in her hoop houses this time of year.