The turf flew high under the watchful eye of Los Angeles climate guru Bill Patzert on Thursday, as Van Nuys homeowners watched their water-guzzling grass being swapped out for California-friendly landscaping.

With the Golden State now in its fourth year of drought and residents facing possible water rationing this summer, he championed conservation rebates that allow homeowners to rip out their lawn and replace it with low-water shrubs — for free.

“There’s no quick fix,” said Patzert, climatologist at the Jet Propulsion Laboratory in La Cañada Flintridge for the past 32 years. “We’re running on empty.

“So if we don’t get some drought relief and start practicing large-scale water conservation, we’re going to go from near-empty to fumes.”

This month, L.A. got a squirt of rain, and February of last year brought even less. With mountain snowpack 20 percent of normal and water reservoirs across the state plunging by more than half since 2012, he said local water agencies have signaled restrictions may be likely after July.

One way to pair back water use is to rip out thirsty green grass, which can pad up to 60 percent of a homeowner’s water bill, and replace it with drought-tolerant flora. And now may be the best time to plant.

“Winter is the new spring,” said Patzert, as landscapers from Turf Terminators scrubbed the lawns from a half-dozen postwar homes on Mammoth Avenue in Van Nuys and put deergrass, penstemon, sage and lavender into beds of crushed grey granite stones or mulch.

With the Los Angeles Department of Water and Power now offering $3.75 per square foot for turf — on the heels of Mayor Eric Garcetti’s executive order in October for citywide conservation — one landscaping company has stepped up to remove grass and replace it with drought-tolerant landscape and automatic drip irrigation for just the cost of the utility’s water conservation rebate.

Since it launched in L.A. in May, Turf Terminators has replaced more than 2,000 lawns, claiming to have saved homeowners up to 45 percent on their water bills.

“It’s going great,” said Andrew Farrell, chief of operations for the privately owned company. “Growth has been awesome. People love us. What we’re seeing here is, when we do one low-water lawn, neighbors notice.

“This is absolutely catching on — we’re hoping slowly but surely to change Los Angeles.”

It didn’t take long for Georgina Cox, whose summer water bill hit $400, to catch on. “I didn’t water much — I’m frugal. I couldn’t keep it up. I think I had the ugliest bloody lawn in the neighborhood,” said the 60-year-old British native of her decision to have her lawn Terminated.

“I am now beyond happy,” she added as she watched the crew at work. “The yard looks fantastic. Look at the pretty flowers. Look at all the drought-resistant plants. This will encourage me to take better care of my yard.”