Climate debate heats up as local gardeners change plants

Everybody talks about the weather, but nobody does it today without ticking off somebody.

The Heartland Institute put up billboards prior to its climate-change conference this week in Chicago proclaiming that the world's "most prominent advocates of global warming" are crazed killer Charles Manson, dictator Fidel Castro and Ted "The Unabomber" Kaczynski.

On the other end of the political spectrum, Forecast the Facts organized folks to protest companies that support Heartland's "climate deniers," and the National Resources Defense Council hosted a news conference Wednesday on the "Killer Summer Heat" the group predicts for Chicago and other cities.

A majority of apolitical scientists who aren't mass murderers or protesters say the climate is shifting and human pollution plays a major role. A recent poll shows that most Americans now think global warming is behind everything from our mild winters to extreme and violent weather,

And suburban gardeners are just wondering what the heck is going on.

"Our Japanese maples are flowering," says Doris Taylor, longtime plant information specialist for the Morton Arboretum in Lisle. "They usually don't flower until mid-June."

While Taylor associates Arbor Day weekend (it was the last weekend in April for those of you who don't celebrate the holiday as festively as the Morton crowd) as the time when the flowering quinces are in full bloom, that species had flowered weeks earlier and "were long gone" by Arbor Day, she says.

Those 80-degree days in March made plants think it was May. My yellow roses that traditionally pop just in time to decorate graves for Memorial Day are a few faded petals away from being gone for good.

These early flowering times are a real problem for people who timed outdoor weddings to take place during traditional blooming season, Taylor adds. But it also has sparked new possibilities.

"Some of the stuff that grows in southern Illinois and Indiana are working here," Taylor says, mentioning temperate plants such as sweet gum and tulip trees.

In a nod to our warming climate, the U.S. Department of Agriculture in January redrew its "plant hardiness zones" to show that our area is no longer firmly in the colder Zone 5. The new, much-more diverse and detailed mapping shows us in the warmer Zone 6 and flirting with a wealth of planting possibilities that once were off-limits.

"It certainly is opening up some opportunities for gardeners," notes David Ellis, director of communications for the American Horticulture Society and editor of "The American Gardener" magazine. "There is a little wiggle room for experimenting with plants that aren't normally hardy in their zone."

Spring hot spells mess with plants, but cold winters are "what stops people from growing subtropical and warm temperate plants," Ellis says. Milder winters led to the USDA changing our plant hardiness zone designation.

Suburban nurseries might start selling plants we usually don't see except on vacations, Taylor says. But she warns gardeners that nature isn't an exact science, and that one cold winter could change the new suburban landscape.

"I don't plan on planting a saguaro cactus in my yard anytime soon," Taylor says.

"Most gardeners see it as an opportunity for the time being," Ellis says, "But if the trend continues, it gets a little bit scary. What the climate giveth, it taketh away. It's a two-way street."

People excited about growing banana trees in their yards might find themselves longing for those colder weather beauties we take for granted. Suburban favorites such as white bark birches, white pines, hemlock and even the Colorado blue spruce aren't comfortable with the direction we are headed.

"They don't like our summer," Taylor says. "If we get warmer, these might disappear on us."