[caption id="attachment_82515" align="alignnone" width="500"] Jay Jensen, chief executive officer of Novavine, says the new 46,000-square-foot greenhouse at the Sonoma Valley nursery will be able to produce more than 1 million vines for planting annually. (image credit: Jeff Quackenbush)[/caption]

KENWOOD -- Amid heightened demand for new grapevines for vineyard redevelopment and new plantings in recent years, Novavine has boosted its annual nursery output to 6 million vines with the opening of its largest greenhouse to date.

Santa Rosa-based Novavine (707-539-5678, novavine.com) on Friday unveiled a 46,332-square-foot, $1.5 million greenhouse at its 27-acre property at 6735 Sonoma Hwy. near Kenwood.

"Four years ago we were grafting 2.5 million vines, and now we're grafting 6 million," said Jay Jensen, Novavine chief executive officer, while walking among rows of custom-built rolling pallets for repositioning grapevines with much less labor.

Indeed, four years ago was a much different environment for grapevine nurseries. The so-called "great recession" of 2008 caused the premium-wine business to significantly contract in 2009--2010. Mr. Jensen told the Business Journal in early 2010 that Novavine's preorders for that season were down 30 percent from those for 2009.

Sales are now double what they were in 2010, according to the company.

Novavine's preorders for the 2014 season are 80 percent of the expanded capacity, which is up because of increased interest in replanting, shifting grape varieties and new vineyards in the past couple of years as the economy has improved, Mr. Jensen said. Significant preordering, rather than speculative vine propagation, is necessary for a grapevine nursery because of myriad combinations of grape varieties, clones and rootstock a buyer may want, he said. The nursery commonly reserves 25 percent of its vine production to make sure what the vines are ordered are viable.

The new greenhouse can accommodate 595,000 vines at a time and can be filled twice a year, producing upwards of 1.2 million vines annually.

Previously, the company's largest greenhouse was a 32,000-square-foot structure on the same property. It can produce 350,000 vines at a time and 700,000-plus a year. Novavine also has two 10,000-square-foot greenhouses in the area.

Vine stock is grown in a 10,000-square-foot greenhouse on a 90-acre property in Yolo County, because the climate is warmer and operating costs are lower, according to Mr. Jensen. Cuttings are brought to the Sonoma Valley property for finishing.

Construction started on the new greenhouse in December, a year after seeking permits from the county of Sonoma. Because of questions about the applicability of commercial-building rules on such a structure and the lack of new grapevine nurseries in the county for years, county Agricultural Commissioner Tony Linegar helped Novavine explain its operations to county planning officials, Mr. Jensen said.

Novavine's new greenhouse has a number of technical improvements to increase labor, water and other operational efficiencies.

The structure has rollup doors on the sides to allow for adjustment of temperature on average days and evaporative cooling for heat spikes.

Also, the vine planters sit in a pallet, or "bench," that rolls on tracks from one side of the facility to the other as the vine matures. The benches can roll out into a covered area for hardening the vines before shipment. What used to take six to eight workers to lift and move trays of vines as they mature before shipment now requires just one worker to roll a tray down the line, according to an employee at the nursery.

The benches also have heating loops above and below to maintain optimum temperature and humidity for the young vines. Dual boilers provide heating redundancy.

Novavine uses probiotics to combat vine diseases. For example, beneficial Trichoderma fungus species are used to fight harmful fungi.

The Kenwood nursery employs 40 full time, swelling to about 200 during the peak grafting period in December.

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