Even grinding recession has not undone growth in one corner of California's drought-parched landscaping sector, where Robert Cornell has spent more than two decades fine-tuning climate friendly gardens.

In Pasadena, a wealthy suburban area northeast of Los Angeles, amid the rows of luxurious flowers and freshly mowed lawns, there is little sign that California is in a drought emergency after three years of sparse rains.

Nor do passersby see any clues that this type of vegetation best suited for temperate to tropical areas really ought not be thriving in this semi-arid Mediterranean climate.

In California, lawns are "completely out of their natural habitat," said Cornell.

"Here normally, you'd have chapparal, buckweed (types of brush). You would have perennial plants that are designed to burn every 40 and 50 years."

The water that comes out of the tap in this area comes from hundreds of miles (kilometers) away, from the mountains of the state's northeast.

But with the drought dragging on, authorities are not ruling out rationing water to residents; watering restrictions are already in place.

Fortunately, one thing is starting to be uprooted in California: the idea (born in wetter climes) that every American homeowner's dream is a white picket fence with a big green lawn behind it.

Part of the change has come from living with drought; some has to do with people making better-informed decisions taking environmental factors into account -- as well as greater demand for natural, climate-cued gardens.

Kent Shocknek, a local television anchor, is among those who simply like the natural style of the climate-attuned garden. He and his wife, Karen, asked Cornell to help then develop "a landscape as ... green as possible, with as little maintenance as possible.

"We wanted something that would blend with the environment, we wanted something that would be pretty and a little more rustic and wild than something manicured, and anchor the hillside, and keep it from sliding," Shocknek said.

-- People who plant azaleas are on the wrong side of history --

With the garden in place, "we haven't seen our utility bill increase, that's been one of the benefits of Robert's work. Our watering system has been turned off since the last rain."

Around the couple's home, Cornell planted Mexican aloe, different tall grasses, yucca and South African plants such as Mole Purge (euphorbia Lathyrus and Characias).

"If you live in Southern California, it's a desert, we should have drought tolerant plants," said Karen Shocknek.

"It's not just gorgeous and architecturally interesting, they're good for the environment as well."

Back when he was specializing in these types of plants 25 years ago, Cornell thought he could see the future.

"The population in California is increasing, and we only have so much water. And we have drought cycles. Sooner or later, the drought cycle is going to meet the population increase. There's going to be a severe drought and some kind of rationing," he recalls thinking.

Now, he said his typical client is someone who has a concern about the environment, often Democrats, he says.

Though at the time his colleagues thought he was a gardening heretic, "today, in the industry, they realize that if they're not on board, they're not going to have a good reputation. It's the way of the future.

"There's a lot of talk about that. They're becoming very progressive. Today, I see in the industry a lot of people saying, this is probably the future, we've got to get on board," added Cornell.

"Azaleas are very thirsty. People who plant that today are on the wrong side of history," Cornell stressed, just ahead of the fifth World Water Forum, which begins in Istanbul next week with the participation of government officials, business people and civic groups from about 180 countries.

Referring to President Barack Obama's effort to encourage environmentally sound job creation, Cornell joked: "I've been a green collar worker for 25 years!"