New Pasadena 'xeriscape' opposite Eaton Canyon -- a showcase of California coastal native plants -- opts for Southern Nevada-style cactus and gravel. No shade, radiating heat, this 'garden' will exacerbate urban heat island effect.

Residential lawn is going the way of the gas-guzzler across southern California. In a horticultural version of the cash-for-clunkers program, the bounty on grass offered by water agencies has gone as high as $4 per square foot. But, as the turf goes out, what's coming in? Poppy-studded cottage gardens? Disturbing tangles of weed cloth, cactus and gravel? What about retrofitting for stormwater capture? What are the ramifications in terms of heat, dust and glare? Above all, as the sprinklers are capped, where will the region's trees get their water?

The answers are there, they're always somewhere, but in this case they're clear as mud. Landscape reform is sweeping California more as an emergency response to drought and less as a considered piece of town planning. Representatives from three of the region's largest water providers, a City of Los Angeles arborist, and a Los Angeles County botanist interviewed for this article all seemed surprised when asked if they had consulted one another about the impact on the region's urban canopy before moving to dry out the lawns in which most of the trees are planted.

In other words, the agencies funding lawn rebates have their eyes peeled on the shrinking elevations of our reservoirs, not the quality of our shade. Preserving the region's trees during drought is down to their customers. That would be us.

Ever tried to kill a lawn but spare the tree standing in it? I have, and succeeded, which is why KCET asked for this article and commissioned another 11 "how to" articles about progressive landscaping to follow it.

But first some background on why everyone who has ever sat under a tree and enjoyed it needs to pay attention. Even the agencies buying up lawn are hard pressed to estimate how much turf is actually coming up. In the last year alone, the Metropolitan Water District of Southern California received applications for the removal of 21 million square feet of lawn. That's land roughly the size of Hancock Park being booked for a Brazilian.

Across Metropolitan's service area from Ventura to San Diego, the de-grassing numbers achieved by local water companies push that total higher. Cities such as Long Beach and Los Angeles have been paying residents to remove lawn for years. The Los Angeles Department of Water and Power, for example, has paid for the removal of more than 11 million square feet of turf since 2009. Whatever the total acreage de-turfed by rebates, it marks only the beginning of the sod-cutter's path. Water companies are banking on what conservation economists call "market transformation." This anticipates that, for every rebate garden they fund, neighbors will follow suit on their own dimes.

Altadena rebate garden after installation. It looks presentable newly finished but don't take bets on how it will wear. There will be negligible shade in a sun-blasted west-facing garden in a hot foothill city. Mulch will wash off berms topped with slick weed-cloth. The driveway and back portion of the garden drain toward the home's foundations and aging retaining wall. There are no gutters or water management incorporated in the design. Cactus and spiny succulent at curb where people will be getting out of cars.

The impacts of rebates and "market transformation" are already tangible on almost every street in drought-struck California. The quality of the succession landscapes range from jaw-droppingly gorgeous to junkyard bad. "We're just in this messy transition," says landscape architect Robert Perry. How messy? The Claremont-based author of "Landscape Plants for California Gardens" and adjunct professor at the USC School of Architecture says, "I'm anticipating a very eclectic and non-aesthetic outcome from seeing all the garden types coming out."

When the éminence grise of landscape reform talks, Southern California is well advised to listen. Perry, a professor emeritus from Cal Poly Pomona, has been publishing prize-winning books on suitable plants for water conservation since 1981. No Southern Californian landscape architect has looked more scientifically at quantifying the gallon-of-water-per-pound-of-wood ratio. Perry has served on state task forces developing water-conserving irrigation guidelines and collaborated with US Forest Service studies looking at the benefits of urban canopies. To augment irrigation, he is arguing for alteration of conventional street curb design to divert stormwater to urban landscapes. Yet masterplanning is slow and, by comparison, the crisis-fueled rush to rebates is not. "Many of these xeriscapes are imploding and heading south in a very unattractive way," Perry says. "We're just setting time bombs everywhere."

There are as many reasons for this as there are ways for weeds to recur in an un-mowable cactus rebate garden. Suffice it here to say that, as unsustainable as curb-to-alley lawn has proved, grass is a tough act to follow. Grassy front yards provide visual continuity. They tamp down dirt. Grass is cooling on hot days. Lawn's cheap to install either by roll or seed. Everything needed to put it in and then keep it up is available at any home improvement store. The smell of freshly cut grass intoxicates every American child who ever rolled down a hill. Turf absorbs stormwater, mitigates mudslides and aids groundwater recharge in rainy season. Affordable maintenance teams are ubiquitous. All the homeowner need know how to do is pay a gardener and roll a green bin to the curb and back.

"Lawn was a simple recipe," says Perry. "Now we're trying to create something more sustainable and have landscapes provide greater benefits. We need to nurture the soil. We need to harvest and impound rainwater. We need diversity of plants. It challenges the public because they don't necessarily have the inherent interest or the time."

Once-treelined street losing its shade. The flaming red leaves of the liquidambar displayed fall colors before the rest of the street's once orderly progression because it went unwatered. The tree is now diseased and should be taken out. The upshot for the house and street it once shaded will be far higher summer heat and cooling billsWe will need to find that interest and time or live with the consequences. The unintended collateral damage of the de-lawning of Southern California could easily be region's trees. It helps to look at the City of Los Angeles to understand just how much is at stake. Urban foresters estimate that more than 60% of the city's urban canopy comes from trees growing in the yards and parkways of private homes. Roughly the same percentage, probably higher, applies to all the cities across the Southland. This is important because those trees grow in the turf yards and parkways targeted by water agency rebates.That it was never a good idea to irrigate trees with lawn sprinklers didn't mean we didn't all do it.The triple whammy of drought, record heat and sprinkler capping stressed residential area trees in northern California so badly last year that Julie Saare-Edmonds, a senior environmental scientist with the California Department of Water Resources, began organizing regional workshops. She got 11 of them in a state that needed 100 times that to even make a dent. She'll be organizing more this year. Those interested should contact their local Urban Forests Council. "It is a big problem because trees represent a huge long term

We will need to find that interest and time or live with the consequences. The unintended collateral damage of the de-lawning of Southern California could easily be region's trees. It helps to look at the City of Los Angeles to understand just how much is at stake. Urban foresters estimate that more than 60% of the city's urban canopy comes from trees growing in the yards and parkways of private homes. Roughly the same percentage, probably higher, applies to all the cities across the Southland. This is important because those trees grow in the turf yards and parkways targeted by water agency rebates.

That it was never a good idea to irrigate trees with lawn sprinklers didn't mean we didn't all do it.

The triple whammy of drought, record heat and sprinkler capping stressed residential area trees in northern California so badly last year that Julie Saare-Edmonds, a senior environmental scientist with the California Department of Water Resources, began organizing regional workshops. She got 11 of them in a state that needed 100 times that to even make a dent. She'll be organizing more this year. Those interested should contact their local Urban Forests Council. "It is a big problem because trees represent a huge long term investment in time and water," she says. "They have really high payback for shade, energy and conservation."

To this Greg McPherson of the Pacific Southwest Research Station of the US Forest Service adds that trees also mitigate flooding, sequester carbon, absorb noise, protect against skin cancer and beautify cities. They also pay their way financially. In a study for the US Department of Agriculture, McPherson found that a single mature shade tree could represent one per cent of a home's value. Properties on well-shaded streets could command three to seven percent higher prices than their unsheltered counterparts. In Los Angeles County, that gives the mature tree in the front yard of a median-priced home the value of $5,000 and the house on the shaded street a boost of up to $40,000.

That value only holds if the tree is alive. Do not wait to care for a tree until it's in trouble, warns Saare-Edmonds. Cut your sprinklers by all means but run new irrigation to trees. Keep them healthy. Stressed trees are most vulnerable to beetle, fungus and bacterial attacks now being monitored by urban foresters. "If you have drought and an insect and a disease you have big problem on big problem on big problem," says Ron Lorenzen. Many of the worst-stressed tress so far, according to Lorenzen, a former street tree superintendent for the City of Los Angeles, are in the San Fernando Valley. In other words, the areas facing the greatest tree losses are the hottest -- ergo, the regions that most need tree shade.

It's unlikely that lawn removal will slow down. Over-watering of lawn combined with driveway hosing, car washing and pools amounted to such waste in the past that outdoor water use routinely equaled or surpassesd what we Southlanders used indoors to bathe, wash and cook. Moreover, California water managers have only had to look east to see just how much water they can wring out of lawns. Since 1999, the Southern Nevada Water Authority has removed more than 179 million square feet of turf saving 9.6 billion gallons of water, or roughly enough to keep Las Vegas going for roughly a year, suburbs, conventioneers, golfers, party animals and all.

Inspiring, yes, but there are crucial differences between Los Angeles and Las Vegas - the first being age. The average Los Angeles junior college sophmore is older than much of Greater Las Vegas. Buying back lawn in Southern Nevada did not as a rule constitute arborcide because there weren't a lot of mature trees in the way. Landscape reform in Los Angeles will have to be done differently and look different unless we want to sacrifice our shade. A second key difference, one many rebate garden installers don't seem to realize, is that most of Southern California is not in a desert. Palo verde trees and cacti are not necessarily suitable here. Coastal California has a Mediterranean climate and, if we want to keep it liveable, our rebate gardens will need to look different and be done differently than those in the Mojave Desert.

In the coming weeks and months KCET will explore how safe lawn conversion can be done around existing trees. The online written series "After the lawn" will address landscape challenges from curb to back fence. If you want to keep lawn, it will tell you how to do it and save water. If you want to go native, we'll be on it. The theme: How to look at your lot and improve its function and beauty while increasing its water efficiency. Stay tuned. Ah, in the meantime, remember your trees. Here's a good brochure on tree irrigation from the Inland Urban Forest Council.

Emily Green is a freelance journalist specializing in western water and horticulture. She has been reporting on drought-tolerant landscaping since 2001, when she succeeded Robert Smaus as a garden writer for the Los Angeles Times. After a year reporting in and around the Mojave looking at Las Vegas's drought adaptation techniques, she contributed the 2008-2011 "Dry Garden" series to the Los Angeles Times.

Follow the entire After the Lawn series:

After the Lawn: Part I

Designing Your New Garden

Caring For Your Turf

How to Remove Your Lawn

Planning Your New Garden