Rain + sun = all it takes to heat the house, keep the lawn green and bake a Sunday roast.

That's the message vendors at the Utah Green Festival tried to get across Saturday to the crowds wandering through the Conservation Park at Jordan Valley.

"If we don't start to get ahead of the curve, we will run out of resources," said Ed Mathieu, who spent the morning selling computerized sprinkler systems, produced by Water Logic, that automatically adjust to changing environmental factors. "We don't make new water. We don't make new fuel. Eventually our growth and waste will get us into trouble."

Hundreds of people — families, businessmen and elderly couples — showed up to take a look at the sprawl of tents set up among the park's shrub, grass and flower displays. There were booths highlighting everything from alternative fuel to cosmetics made of plants.

"We've learned a lot about sustainability and water conservation," said Mirinda Schiele, of West Valley City, as she moseyed from booth to booth with her husband. "We're excited to see how we can start using some of these tips at our house."

Schiele was particularly intrigued by the idea, presented by Frontier Sales, of collecting rainwater to use for landscaping.

"I'm all about saving money on the water bill," she said.

David Luke, president of Frontier Sales, said he saved between $100 and $200 this summer by watering his shrubs with runoff from his roof.

"A lot of people don't realize how much water you can collect from just a small amount of rain," he said. "Even in Salt Lake City you're going to get a lot of water."

The concept of minimizing outdoor water consumption — called xeriscaping — was a hot topic Saturday.

"I'm looking at buying a new house, and I want to keep things simple," said Nathan Waldrep, of Midvale. "Landscaping in a desert-friendly way just seems smart."

Booths advertising solar power were also popular.

"I want to get off the grid so bad my teeth hurt," said Jen Ottens, of Lindon, as she fiddled with a sample solar panel, making it turn a toy motor on and off. "We can holler all we want about big companies polluting the air, but we can do something at home — and I intend to."

Even little changes in consumption can make a big difference, vendors said.

Just by trading a conventional oven for a solar-powered oven, homeowners can use up to 60 percent less electrical energy, said Joe Crane, owner of Kitchen Kneads.

"You save a lot of money and you do something good for the environment," he said.

A lot of people at the fair agreed that "going green" isn't just about saving the planet. It's also, said Eric Lemonnier, of Herriman, about "doing yourself a favor."

"I don't care if you believe in global warming," he said. "The truth of the matter is, in the long run, these new technologies are going to save us money and improve the quality of the air we breathe."

e-mail: estuart@desnews.com