They're popping up in nearly every Southern California neighborhood. We're talking about weekly farmers markets, where local farmers sell produce they say they grew themselves, and often claim is pesticide-free.

There are now more than 300 farmers markets in the LA area, with more opening every month. But an NBCLA undercover investigation has revealed that some farmers at these markets are making false claims and flat-out lies about the produce they're selling.

Farmers markets have become wildly popular with shoppers like Jami Hoffman, who buys her produce every Sunday at the farmers market in the Larchmont neighborhood of LA. She says she shops there because she thinks the produce is fresher than what you get at supermarkets.

"It's all about local, and getting it directly from the farmers," Hoffman said.

NBCLA's investigation began this summer, when we bought produce at farmers markets across the LA area, and then made surprise visits to farms where we were told the produce was being grown.

We found farms full of weeds, or dry dirt, instead of rows of the vegetables that were being sold at the markets. In fact, farmers markets are closely regulated by state law. Farmers who sell at these markets are supposed to sell produce they've grown themselves, and they can't make false claims about their produce.

We did find plenty of vendors doing just that, like Underwood Farms, which sells produce at 14 markets, all grown on a family farm in Moorpark.

But our investigation also uncovered vendors who are selling stuff they didn't grow, like Frutos Farms, which sells at seven different farmers markets in LA and Orange counties.

During our investigation, we bought 26 different types of produce from their stands at the Century City farmers market, at the Larchmont market and at the Buena Park market.

Frutos Farm's state permit to sell produce at farmers markets says their farm is in Cypress.

NBCLA asked owner Jesse Frutos, "Everything you sell at farmers markets is grown in your Cypress field?"

Jesse responded, "Correct...everything."

But when NBCLA made a surprise visit to the Cypress field listed on its permit, Frutos couldn't show us most of the produce he was selling, such as celery, garlic, and avocados.

So NBCLA asked, "Do you grow avocados here?"

"Avocados? No, not here on the lot. … That I'll be honest. That stuff came from somewhere else," Frutos said.

Somewhere else? NBCLA's undercover cameras followed Jesse's trucks on farmers market days, and saw him going to the big wholesale produce warehouses in downtown LA.

We saw him loading up his truck, with boxes of produce from big commercial farms as far away as Mexico. He bought many of the types of items we saw him selling at the farmers markets.

After documenting this, NBCLA asked Jesse, "You are selling some things at farmers markets that you didn't grow, that you got at wholesale produce markets?"

Jesse admitted, "Yes."

And we investigated other vendors, like Juan Uriostegui, who sells produce at the West Hollywood farmers market on Mondays.

He tells customers that everything he sells is grown on his farm in Redlands, in San Bernardino County.

We bought some of his broccoli, and the same day, we showed up at his farm with officer Allan Lampman of the San Bernardino Department of Agriculture.

Lampman asked Uriostegui to show him where he was growing broccoli, but all the farmer could show him was a patch of dry dirt.

"I'm looking at the fields, saying, 'I don't think you grew that broccoli,'" Lampman said.

In fact, Uriostegui was already issued a fine earlier this year by San Bernardino County for selling produce at another farmers market that he didn't grow.

And during our investigation, NBCLA examined another big claim made at farmers markets -- that their produce is "pesticide-free."

NBCLA bought one container of strawberries, from five different vendors, at five farmers markets, including a vendor called "The Berry Best," at the Torrance farmers market.

NBCLA's undercover shopper questioned the Berry Best's owner about the strawberries:

"These are pesticide-free?"

Owner Mary Ellen Martinez responded, "Yes, they are."

To see if that's true, we took our five samples to a state-certified lab, and had them tested for pesticides.

Results showed three out of five samples we tested sold berries that did contain pesticides, including the sample from the Berry Best.

NBCLA went back to Martinez.

"We found four different pesticides in your berries. You don't how that happened?" we asked.

Responded Martinez, "Nope."

She later said pesticides might have drifted into her field from neighboring farms. But according to our lab, that's unlikely because the pesticide level on her berries appears too high to have drifted from another farm.

Martinez ended the interview with NBCLA, telling us to leave her stand, "You're getting on my nerves right about now."

By the end of our investigation, we found vendors who make false claims selling at more than two dozen farmers markets.

That's upsetting to loyal farmers market customers, like Hoffman, who shop weekly at the Larchmont farmers market.

"I feel like I want to take my vegetables back," said Hoffman.

Because of the NBCLA investigation, Frutos Farms has been issued a notice of violation by the Orange County Commissioner of Agriculture for selling produce it didn't grow.

Under state law, it could face a fine, and/or be suspended from selling at farmers markets for a period of time.

Frutos Farms has the option of contesting the notice.

So, how do you, the customer, know if a farmer is selling locally grown produce that really came from his farm?

Operators of farmers markets we spoke to suggest shoppers get to know vendors they buy from, and ask them a lot of questions. Ask for the exact location of the farm where the produce is grown. If they claim their produce is "pesticide-free," ask them what methods they use to control pests on their crops. Ask exactly when the produce was picked.



If the farmer can't give you specific answers, or seems unwilling to answer your questions, market operators say you should walk away.