Agribusiness  April 4, 2019

Gardening adapts to climate change

At the risk of sounding like a cranky old man on his lawn spouting cliches more worn than socks with holes in them, James Klett knows the Colorado he lives in now is far different than it was 20 years ago.

So, OK, back in his day, there were rules of gardening, and they liked them. The afternoon brought helpful showers. The first killing frost happened a couple of weeks after Labor Day, if not on the holiday weekend. It was (probably) all right to plant after Mother’s Day. Wild storms were really rare, and summers weren’t 100 degrees.

Now everything’s different, said Klett, a professor of landscape horticulture and nursery management who has studied climate change for Colorado State University. Now the growing season extends to mid-October. Summers are scorching. The weather seems more extreme, from afternoon storms that frequently bring hailstorms, including two last year that shredded gardens and punched through rooftops, to spring snowstorms that make it risky to plant anything fragile as late as mid-May.

Higher temperatures throughout the year have brought more disease and insects in addition to the crazier weather.

“Warmer weather does seem to bring more challenges,” Klett said.

Gardening in Colorado is already a challenge, given the extremes in temperatures here and the uncertainty that living a mile high can bring. So many of the weather patterns listed above may be a product of the state as much as climate change.

Ken Olsen, the owner of Eaton Grove Nursery for 37 years, has seen a lot in Colorado, and nothing in the past few years strikes him as particularly unusual, though he does acknowledge the climate seems to be changing, as those bitter-cold temperatures in winter aren’t nearly as common as they used to be. The industry also is adjusting to it, as Olsen heard a talk at a recent conference addressing climate change.

The hardiness zones, the areas of the U.S. that show the extreme temperatures of a region, have always played a little havoc with Eaton Grove, given that Ault just down the road is where they draw the line between zones 5 and 4. Zone 5 describes an area where the lowest it will get is -20 degrees. Zone 4 means it can get as low as -30 degrees.

“Only that zone 4 hasn’t really been achieved in the last few years,” Olsen said.

Those zones have changed since 1990, according to the National Oceanic and Atmospheric Administration, to reflect the warmer weather that Olsen was referencing. But they haven’t changed enough to have a real effect on planting gardens in Colorado, Olsen said, as most plants are dormant in the dead of winter here anyway. Late spring snows aren’t all that unusual in Northern Colorado, Olsen said.

“We get a week of nice weather, and they think it’s time to plant the tender plants outside,” he said. “We really need to wait until after Mother’s Day, and then we need to be prepared to cover them. We still get cold spells that come down. We really can’t plant any sooner than we have for the past 100 years.”

The best way to prepare for all the crazy weather is to grow the plants that have thrived here for thousands of years. Those are usually perennials and are called native plants, said Mary Phillips, the senior director for the Garden for Wildlife program for the National Wildlife Federation.

“They have adapted for eons,” she said. “They can usually make it through any significant changes to the weather from season to season.”

Native plants also help the wildlife that are undoubtedly trying to adjust to the changing climate as well. The federation recently launched a nationwide pollinator garden challenge encouraging gardeners to plant for bees and others that help our plants grow. Colorado had more than 7,000 gardens answer the call, one of the best in the country, Phillips said.

Focusing on native plants doesn’t mean that you can’t mix it up a bit, and the later growing seasons the last few falls have meant good things for plants that typically haven’t done well in Colorado, Olsen said. But plants that naturally occur in the landscape may not only help the critters, it may help your sanity as well.

“What they plant can be really beautiful,” Phillips said, “but if they can also really help the climate, that’s really a key thing.”

At the risk of sounding like a cranky old man on his lawn spouting cliches more worn than socks with holes in them, James Klett knows the Colorado he lives in now is far different than it was 20 years ago.

So, OK, back in his day, there were rules of gardening, and they liked them. The afternoon brought helpful showers. The first killing frost happened a couple of weeks after Labor Day, if not on the holiday weekend. It was (probably) all right to plant after Mother’s Day. Wild storms were really rare, and summers…

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