Vineyards in Washington are being bought and converted to marijuana farms by organised crime outfits, US state officials say.

Police in the Yakima Valley, one of the region’s largest vineyard areas, have swooped on seven vineyards so far this year. All had been converted to illegal marijuana production – a significantly more profitable crop than the Chardonnay for which the region is more well known.

State authorities in the valley say that around 110,000 cannabis plants, used to make marijuana, and worth around US$100m (£52.6m) on the black market, have been seized this year alone.

‘This year, we’re probably going to surpass [the volume of seizures in] 2007 easily,’ said Rene Rivera, heading the Drug Enforcement Agency’s investigations in the area.

In 2007, 296,611 plants were seized – more than double the number confiscated the previous year.

According to news agency Associated Press (AP), the vineyards are bought by organised criminals living in Mexico. The vineyards are then registered under fictitious names, or those of relatives, to avoid suspicion or investigation.

Cannabis plants, however, require significantly more water for irrigation than vines – often one of the first signs a vineyard is being used to grow plants the drug.

The Yakima Valley, also home to fruit orchards and hop fields, is an important pipeline in the North American drug trade, with access to the cities of Seattle and Portland.

However, vineyard purchases by marijuana producers in the region are likely to decline. Vicky Schalau, executive director of the Washington Association of Wine Grape Growers told AP that, after ‘numerous busts’, it was unlikely more attempts would be made to convert vineyards in this fashion.

The Yakima Valley is Washington’s oldest wine region.

Written by Oliver Styles