California’s Fog Is Fading Away — Now What?

October 17, 2023

The Effects of Fog in Grape Growing in Napa Valley

Flora Springs Winemaker Enriquo Bertoz gives his opinions on the effects of Fog on Grape-Growing to Wine Enthusiast.

Fog is to central and Northern California’s wine country what garrigue is to Southern France’s—it’s an intrinsic part of California wine’s character.

Effects of Fog on Grape-Growing

Fog acts like a cool sip of water on a hot day for parched vines—not as great as a dip in the pool (rain), but better than the alternative (nothing).

“Fog acts like a stress reliever during the summer,” says Fulldraw Vineyard’s cofounder and winemaker, Connor McMahon. “In drought years especially, I love seeing fog, because it holds moisture in soil, tucks it in like a blanket. Fog can also protect grapes from the sun. In Paso Robles, it gets so hot—in August and September we had six days of 115 degrees. A little bit of fog makes a huge difference.”

But McMahon says that since 2011 when he began working in Paso, he’s seen a significant decrease in fog events. In a bid to create relief for struggling grapes, McMahon says he started using shade cloth in 2013.

“It’s essential to protect the fruit from direct sunlight when the rain and fog aren’t there,” McMahon says. “And we don’t want to overstress our water table and water the grapes all day, which is the alternative.”

Enrico Bertoz, winemaker at Napa’s Flora Springs, has also been alarmed by the drop in fog in recent years. “In the past few years, we have experienced a decline in the duration of the fog during the summer months,” Bertoz notes. “Ten years ago, the fog lasted through much of the day, and now it burns up more quickly in the morning. Where most of our vineyards are located in Rutherford and Oakville, we receive fog from both the San Pablo Bay and the Chalk Hill Gap in the Mayacamas, which is incredibly important.”

Bertoz explains that the fog helps “retain natural acidity in the grapes and prevent sunburn and heat damage.” And this year, Bertoz is happy to report, the growing season has delivered plenty of fog, something he also links to a longer growing season, which in turn ensures even ripening and full phenolic maturity.

At this point, a clear, traceable line from fog—or the lack thereof—to definitive effects on the development of grapes has not been established. Observations like Bertoz’s are backed up by one of the only comprehensive academic studies of fog’s impact on vegetation in general, published in Geophysical Research Letters.

Tracking the impact of fog through satellite imagery and remote sensing data, researchers say that fog has a “continuous positive impact” on vegetation in drier regions. Fog, the authors write, helps plants maintain “photosynthetic function and sustain biogeochemical dynamics,” and can reduce drought stress by up to 36% off the coast of southern California.

At Flora Springs, when the fog doesn’t deliver that much-needed hit of moisture, they cope by “adding plenty of water and pruning as few leaves as possible [to encourage shading] in the fruit zone to ensure as much water as possible was retained within the vines,” Bertoz explains, adding that the periodic watering helps counteract what would otherwise be an “expedited sugar ripening process.”

Take Nothing for Granted

Coming off the wettest winter in decades, winemakers are clear on one thing: Nothing is a given anymore.

Joe Nielsen, general manager and winemaker at Ram’s Gate Winery in Sonoma, concurs that fog is another shifting factor that vintners should begin to monitor.

“I come from the Midwest, and when I came to Northern California, the fog struck me as such an anomaly,” Nielsen says. “Fog is so important, because it acts as a natural air condition, and is essential for mitigating both the highs and lows of temperature during the growing season.”

Anecdotally, Nielsen says that he’s noticed differences in the fog, but says he couldn’t begin to estimate how much it has changed.

“There’s no way I could say we get 20% more or less at this point,” Nielsen admits. “It’s just clearly more erratic, along with everything else. But winemaking is just getting more refined every day, and because fog is so important to grape-growing, we definitely plan to monitor it more closely. We measure and track everything else in the vineyard—why not fog?”

“The weather has been so weird for the past years, it’s clear that we can’t take anything for granted,” says Dave Low, winemaker at Papapietro Perry in Healdsburg. “We’ve definitely noticed less fog in the past few years, but I haven’t noticed that it has led to a chemical difference in the grapes. They look the same, and they taste the same. But we are picking them a month earlier than we used to, and some of that is probably due to less fog.”

Fog, Low says, is something he plans to keep an eye on in the coming years, to establish if there is any link between a reduction of fog and changes in the glass.

Our Vineyards

Flora Springs produces varietal wines ranging from Sauvignon Blanc and Chardonnay to Merlot, Cabernet Sauvignon and other red Bordeaux varietals. Each year the family selects a small percentage of the yield for their own wines, selling the remaining fruit to neighboring Napa Valley wineries. This selection puts the focus on quality, not quantity, resulting in hand-crafted wines that meet the family’s exacting standards. Read more about our vineyards here.

John Komes on His 44th Napa Valley Harvest

November 7, 2022

“I’ve never seen anything like it,” said John Komes, speaking about the 2022 harvest.

He should know, he’s been through 44 of them! That’s right, this year marked John’s 44th harvest at Flora Springs.

John Komes, Flora Springs Winery

Here’s how he described it: “It was a unique year to say the least. In May a freak hailstorm passed through Napa Valley, part of a system that also brought lightning and even snow to regions to the north of us. A relatively cool summer was followed by an extended heat wave starting Labor Day weekend that dashed any hopes of a leisurely harvest. We brought in our white grapes as fast as we could. And then, following all that heat we had a day of rain, heavy at times but really just enough to knock the dust off the vines. By mid-September, thankfully, the weather was absolutely beautiful…foggy mornings, sunny days and cool nights. We were able to bring in our Cabernet at a nice even pace and the fruit looked fantastic. Good color, great flavors, and even with higher sugar levels, the natural acidity held the grapes’ structure intact. Mother Nature sure had a mixed bag of tricks for us this year, but I’m optimistic about the quality of our 2022 vintage.”

We Have a Thirst for Conserving Water

May 30, 2022

When you live in California, you understand deep down that water is a precious resource. Periodic droughts have been a fact of life here for decades if not centuries, and even in years when winter storms are plentiful, our Mediterranean climate means we get very little – if any – rain from May through September.

That’s actually good for grape growing, since wine grapes don’t require as much water as many other crops. But grapevines do need some water, and as farmers we’re always looking for ways to irrigate as judiciously as possible. It begins by studying our soils.

Komes Ranch Rutherford Napa Valley

One vineyard or even one block can have several types of soils; Napa Valley has more than 100 soil variations. We know that soils heavy in clay need less water than sandy soils, which drain more easily. So we adjust our irrigation regimes to match these different soil types.

For example, at the Komes Ranch, we have six irrigation zones within one 15-acre block. Once we’ve “mapped” the soils, we use several different technologies to measure vine stress during the growing season. These include aerial images (known as Normalized Dierence Vegetation Index or NDVI) that help us understand which sections of our vineyards are undergoing heat stress. We also use fancy sounding evapotranspiration sensors, sap flow meters and soil sensors that measure the water content of our soils and stress of the vines.

By using these measurements, we are able to precisely target the areas of our vineyards that need irrigation. Over the last few years these technologies have resulted in water savings of approximately 50%. What’s more, we’ve found that being more precise in our irrigation practices results in higher quality grapes, a win/win for us and the planet!

Vineyard Views Napa Valley

Napa Valley Vineyards

With estate properties stretching from the cool, rolling hills of Carneros to the famed sub-appellations of Oakville, Rutherford and St. Helena, Flora Springs produces varietal wines ranging from Sauvignon Blanc and Chardonnay to Merlot, Cabernet Sauvignon and other red Bordeaux varietals. Each year the family selects a small percentage of the yield for their own wines, selling the remaining fruit to neighboring Napa Valley wineries. This selection puts the focus on quality, not quantity, resulting in hand-crafted wines that meet the family’s exacting standards. Learn more about our Napa Valley vineyards.

Sustainable Farming

As a family that came to the wine business as farmers first, our love of the land influences everything we do. Our environmental stewardship led us to embrace sustainable and organic farming early on. Our search for superior vineyards sites led us to acquire land in some of Napa Valley’s finest appellations, including Rutherford, Oakville, St. Helena and Carneros. Over the years, as we’ve planted and replanted this land to vines, we’ve experimented with rootstocks, clones, trellising systems and a variety of viticultural techniques, always striving to produce the best possible quality.

Every wine we produce, from Trilogy to our single-vineyard Cabernet Sauvignons, is crafted to express the singular soils, microclimates, and beauty of its respective vineyard origins. Learn more about our sustainable farming practices.


In the Vineyards

July 29, 2021

With harvest just around the corner we thought we’d take you through a pictorial of the 2021 growing season so far. Though we have yet to bring our grapes in, our weather has been lovely in Napa Valley and we’re looking forward to another outstanding vintage.

February:Vines are Dormant

Vineyard in February

These neatly pruned vines in John Komes’ vineyard were dormant back in February, patiently waiting to wake up for the 2021 growing season.

March: Budbreak

Budbreak, when buds swell and the vines put out their first leaves, occurred right on time, rippling through our vineyards in March.

May: Fruit Set

Vineyard Flowering

Just a few weeks later in May, flower clusters destined to become grapes began to appear, a growth stage known as fruit set. Photosynthesis and vine growth sped up dramatically.

Late May: Canopy Management

Napa Vineyard Late May

Within a couple of weeks, the vines had full canopies which we managed by hand throughout the season to ensure the grapes had just the right amount of dappled sunlight.

June: Berry Clusters

Vineyard Berries

The first berries to form in June were green and hard to the touch. The clusters looked very healthy though, and we began to get a sense of how big the vineyard crop is going to be (hint: small).

July: Veraison


In late July the fruit started to go through veraison, the period when the grapes soften and develop color. Just a few weeks from now we’ll be in harvest, and at Flora Springs we can’t wait!

The Places In Between

August 10, 2020

One of the many reasons Napa Valley is such a superb region for growing wine grapes is its incredible diversity. Although a mere 30 miles long and several miles wide, the valley is home to a wide range of microclimates and a vast array of soil types. Over the years, this diversity has led vintners and growers to create defined grape growing areas within Napa Valley. These areas, which reflect their regional designations, are called American Viticultural Areas, or AVAs.

Famous Napa Valley Sign

The Napa Valley is itself an AVA having received its own designation in 1981. It is California’s first recognized AVA and the second in the United States. Over time, sixteen “nested” AVAs have been designated within the Napa Valley AVA. Flora Springs owns and farms vineyards in five of these, including the St. Helena, Rutherford, Oakville, Oak Knoll and Los Carneros AVAs.

But what about the places in between, the regions in Napa Valley that are not part of a nested AVA? If you look at a Napa Valley AVA map, you can see there are several areas that lay outside of the nested AVAs, in fact, our Kairos Vineyard, home to our Out of Sight Cabernet Sauvignon, is in one such area.

Kairos is just south of the Stags Leap District, kind of wedged between the Stags Leap, Oak Knoll and Coombsville AVAs,” says General Manager Nat Komes. “So when we bottle the Out of Sight Cabernet, we use the Napa Valley appellation on the label. But that doesn’t have any bearing on the quality of the vineyard or wine.”

In fact, there are plenty of properties renowned for high quality grapes and wines that do not lie within a nested AVA. Examples include sites that are between the St. Helena and Howell Mountain AVAs as well as vineyards found east of Oakville in the mountainous area known as Pritchard Hill.

For now, says Nat, “The Kairos Vineyard is a perfect example of the quality that can come from areas outside the nested AVA system.” For proof, look no further than Flora Springs Out of Sight Cabernet Sauvignon.

Out of Sight Cabernet Sauvignon

Third Generation Komes-Garvey Family Members Take the Helm

February 25, 2020

Flora Springs Napa Valley Estate Vineyards

The third generation of Napa Valley’s Komes-Garvey family is taking the helm here at Flora Springs. Our family-owned winery with a history dating back over forty years will be led by General Manager Nat Komes, son of Flora Springs Co-Founders John and Carrie Komes. Nat will be joined by his cousins and Proprietors, Michelle Dolge, Nadine McIntosh, Lisa Meyers and Jeannine Ross. Sean Garvey, son of Co-Founders Julie and Pat Garvey, will continue in his role as vineyard manager.

This represents a bright new chapter for Flora Springs in which our family’s next generation can be laser focused on excellent winemaking, customer service and hospitality at our popular Tasting Room in St. Helena, as well as innovative sustainable farming efforts over our family’s 257 acres of prime Napa Valley vineyard land.

“My cousins and I are excited about this new chapter of Flora Springs. Our long time club members and customers should know that the high quality of our wines will not change, nor will our tradition of warm hospitality. If anything, as we put our spin on it, Flora Springs 2.0 will be even better,” says Nat Komes. “I also want to say that we’re very thankful to our parents and grandparents for giving our generation the opportunity to carry on their legacy. They’ve worked hard to pave the way for us.”

With a new leadership team in place, 257 acres of prime Napa Valley vineyard land and an ideal Tasting Room located on Highway 29 in St. Helena, Flora Springs is well-poised for our next chapter. Our family’s vineyards span six sub-appellations and include: P&J Vineyard in St. Helena; select blocks of the Komes Ranch in St. Helena & Rutherford; Garvey Family Vineyard in Rutherford; Windfall Vineyard in Rutherford; Crossroads Ranch in Oakville; Kairos Vineyard in Napa Valley; Red Hen Vineyard in Oak Knoll; and Sunset Knoll Vineyard in Carneros. These vineyards are the consistent, long time sources of Flora Springs’ popular, highly-acclaimed wines, including our flagships, Trilogy and Soliloquy, as well as our Single Vineyard Cabernet Sauvignons.

“My sister Julie and I along with our spouses founded and grew Flora Springs from the ground up, but the wine business has changed since we began,” says John Komes, who noted that the sale of the Komes Ranch was a matter of estate planning. “Our family’s third generation grew up in this business and has a great understanding of it. It’s time for us to pass the baton to them.”

Flora Springs Vineyards

With estate properties stretching from the cool, rolling hills of Carneros to the famed sub-appellations of Oakville, Rutherford and St. Helena, Flora Springs produces varietal wines ranging from Sauvignon Blanc and Chardonnay to Merlot, Cabernet Sauvignon and other red Bordeaux varietals. As a family that came to the wine business as farmers first, our love of the land influences everything we do. Our environmental stewardship led us to embrace sustainable and organic farming early on. Learn more about our vineyards.

Visit Flora Springs Tasting Room

We look forward to welcoming you in Napa Valley for wine tasting while enjoying views of flourishing vineyards and the western hillsides. Plan your visit today.

Vineyard Update from Winemaker Paul Steinauer

June 20, 2019

In Napa Valley this time of year, you’re likely to see vineyard crews scattered amongst the vines. “What are they doing,” you ask? They are Shoot Thinning and Leaf Pulling.

Shoot thinning and leaf pulling are part of overall vineyard canopy management, as seen here in Sauvignon Blanc vines at our Soliloquy Vineyard. Learn how our Soliloquy Vineyard is entirely unique to Flora Springs and distinct from more common Sauvignon Blanc vineyards in Napa Valley.

Winery with vineyard views

Shoot thinning is a process in which any unnecessary shoots are removed—typically those in the lower regions of the vine. Removing select shoots allows the vines’ energy to be directed towards the primary shoots, which will ultimately bear fruit.

Leaf thinning is conducted for a variety of reasons, particularly in wet years like this one when the canopy tends to be vigorous. Too much vigor can lead to vegetative characteristics—which we don’t want! Removing the leaves curtails this issue. Leaf thinning also opens up the canopy, allowing increased air flow and quicker drying in the event of morning dew or rain, and to prevent mildew in humid conditions. This opening of the canopy also increases light penetration—which is needed for photosynthesis. Sunlight exposure improves grape quality, protects the berry, and also elevates the phenols and polyphenols that are responsible for the color, taste, and flavor of the wine.

Napa Valley Vineyards

While this work is being done, the crews are also positioning the shoots. The shoots may be 24”–36” at this point. If we are working in a vineyard that has a vertical trellis system, there will be a series of horizontal wires running from one end of the row to the other. As the vine grows, the shoots will be tucked into the wire trellis to allow for what is commonly referred to as VSP, or vertical shoot positioning. This allows further opening of the canopy. There are other types of trellises, but VSP is the primary system implemented in most Flora Springs vineyard blocks.

Napa Valley Vineyards

After the initial thinning pass, each block will be monitored in the weeks to come to determine when/if additional passes are to be made.

Winemaker Update 2017 #4

September 8, 2017

Merlot in Our Estate Vineyards

We have officially picked all of our Pinot Grigio and Sauvignon Blanc for the year. We started the Pinot Grigio on August 15th, and finished the Sauvignon Blanc on August 31st.

We then started harvesting the Lavender Hill Chardonnay in Carneros on September 6th. The very next day, we received Merlot from the Estate. This is the earliest date on record for reds.

Harvest 2017
Vineyard Crew at The Estate

The last week was pretty crazy…Phoenix-like temperatures in the 115 degree range! On top of that, the valley was blanketed with smoke from a fire burning in Butte County. Fortunately, both have subsided and we are back to average harvest temperatures once again…at least for the time being.

We will be bringing in additional Merlot, as well as Petit Verdot from Oakville, on Monday and Tuesday. Then we will finish up with the last of the white grapes on Wednesday.

The harvest has been pretty fast and furious thus far – keeping things exciting. We were very proactive with our irrigation regimen before and during the heatwave, so the fruit is still in excellent condition. We are extremely pleased with the quality thus far, and expect to make some fantastic wines!

Vineyard Update by John Komes

July 20, 2017

by John Komes

Leaf Removal at Our Crossroads Ranch in Oakville


Over that past few weeks our vineyards have been abuzz with activity. As farmers, our family constantly tends to the vineyards which means meticulous care for every vine throughout our properties in Napa Valley.

With the immense amount of rainfall received over winter, we are seeing a lot more vigor than in previous vintages. Earlier this month we kept busy with leaf removal and shoot positioning to foster adequate light through the canopy and properly see each cluster to maturity. Things are looking great out there and we anticipate a bumper crop for the 2017 vintage.

Over the years, my family has acquired nearly 350 acres of vineyards – which means we have spent much time planting and replanting vines. The newest of late, is the replanting of a 15-acre fallow block on our Crossroads Ranch to Cabernet Sauvignon Clone 2. We anticipate this vineyard to come to fruition in the next 3-to-5 years with excellent Oakville fruit. Stay tuned!

Replanting Our Crossroads Ranch in Oakville
Replanting Our Crossroads Ranch in Oakville

Winemaker Update 2017 #2

May 11, 2017

“To ensure we are obtaining only the most premium fruit, we have had to make the difficult decision to replant vineyards when the quality starts to deteriorate due to various forms of vine disease. Two of our Cabernet blocks in our Oakville Crossroads vineyards have recently been pulled out. This vineyard site in Oakville at our Crossroads vineyard had previously been planted to Chardonnay, and has now been re-developed and will be planted to Cabernet very soon.

This is a newly-planted vineyard, also at our Oakville Crossroads vineyards. This was formerly Pinot Grigio, and has also now been planted to Cabernet.

Crews are currently going through all of our vineyard blocks and suckering. Buds, or nodes at the base of the leaves, produce shoots called laterals or suckers. By doing this, more energy is focused on the vine – which increases grape quality. It also keeps the vine off the ground, and helps prevent unwanted molds and various insects.

The area between the nodes, the internodes, are supported with adjustable ties which are attached to guide wires. As the vines mature during the growing season, the guide wires – and thereby the vines – will be raised on the trellis system. The vines will be trained in such a way as to evenly distribute the clusters of fruit, and the canopy of leaves will protect the fruit from direct sunlight in order to prevent burn. The canopy will be open just enough to allow filtered light, as well as sufficient airflow throughout the vineyard.

Finally, we have the start of bloom in our Hillside Reserve Cabernet Vineyard.”

—Winemaker Paul Steinauer