Current Weather
The Spy FM

Spring May Have Sprung, But Most Gardens Are Still Slumbering

Filed by KOSU News in Science.
March 21, 2013

For vegetable lovers, the start of spring can be a cruel tease, hinting of a feast of just-picked peas and spinach and beets, but delivering instead tired iceberg and romaine shipped from distant climes.

“It’s zero here right now,” Terry Nennich reported Wednesday morning, the first official day of spring, from Grand Rapids, Minn. So much for spring. Not only was it well below freezing, but the ground remained blanketed by 2 feet of snow.

Nennich is a veggie guy, a horticulture research director at the North Central Research and Outreach Center of the University of Minnesota, which stands about 120 miles from the Canadian border. Undaunted by the fact that spring still looks a lot like winter, Nennich takes the bringing of vegetable bounty to the northland as a personal and professional challenge.

“We have plants ready to grow in the ground,” Nennich says. “Those beet and onion seedlings were started in heated greenhouses and are just waiting for enough warmth to transplant.”

Across the country, commercial vegetable growers and home gardeners are trying to gauge the impact of a cold, wet spring, balancing the itch to plant with the knowledge that flirting with spring’s whims can bring heartache.

Sun isn’t the problem. By March, even northern Minnesota has enough daylight for plants to grow. The problem is cold.

Hardy spring crops like spinach and kale can freeze solid in a late cold snap, thaw out and keep right on growing. But to start out, even the tough ones need earth that’s warmed up to 45 or 50 degrees for seeds to sprout. Plant too soon, and seeds rot. The few plants that do grow remain puny and vulnerable to disease.

So impatient growers hustle the warming process along with blanketlike polyester row covers and plastic-covered high tunnels, which are like unheated Quonset huts. (We’ve chronicled how growers Zach Lester and Georgia O’Neal use these techniques to keep greens growing all winter long through snow and frost in Unionville, Va.)

Growers in Minnesota have embraced these techniques over the past decade, extending the growing seasons by 30 percent. They can start selling locally grown spring vegetables to farmers’ markets and restaurants two months earlier, Nennich says. “There’s a big market in the restaurants for local greens.”

But high tunnels don’t warm the soil enough to accelerate less hardy crops like tomatoes, peppers and cucumbers. Their seeds won’t sprout unless the earth is 60 or 70 degrees, and they shrivel at a hint of frost.

So Nennich and his colleagues are attacking the problem at its roots, with solar-heated soil.

They run corrugated plastic drainage tubes through the soil under hoop houses, and connect the tubes to solar panels. Warm air is pulled by a fan all winter long, countering the region’s bitter cold; it can thaw icy soil by March 1 and banish frost by mid-March.

Nennich and his colleagues are working on perfecting the solar soil heater design so it’s cost-effective. He envisions a future when fruit trees grow in solar-heated tunnels, bringing a touch of Georgia to the far north.

But for now, he’d be happy to see spring. [Copyright 2013 NPR]

Leave a Reply

5AM to 9AM Morning Edition

Morning Edition

For more than two decades, NPR's Morning Edition has prepared listeners for the day ahead with two hours of up-to-the-minute news, background analysis, commentary, and coverage of arts and sports.

Listen Live Now!

9AM to 10AM The Takeaway

The Takeaway

A fresh alternative in morning news, "The Takeaway" provides a breadth and depth of world, national and regional news coverage that is unprecedented in public media.

View the program guide!

10AM to 11PM On Point

On Point

On Point unites distinct and provocative voices with passionate discussion as it confronts the stories that are at the center of what is important in the world today. Leaving no perspective unchallenged, On Point digs past the surface and into the core of a subject, exposing each of its real world implications.

View the program guide!

Upcoming Events in your area (Submit your event today!)

Streaming audio and podcasts

Stream KOSU on your smartphone

Phone Streaming

SmartPhone listening options on this page are intended for many iPhones, Blackberries, etc. with low-cost software applications available to listen to our full-time web streams, both News on KOSU-1 and Classical on KOSU-2.

Learn more about our complete range of streaming services

We're perfecting the patient experience - Stillwater Medical Center