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| The Platt Vineyard lies only five miles from the ocean, yet is able to ripen both Pinot Noir and Chardonnay. |
Dr. Daniel Roberts operates a viticultural consultancy called Integrated Winegrowing. Daniel is a soil scientist/viticulturist who advises on the development and operations of vineyards that grow wines for what he considers to be the 99th percentile of the industry. Many of the vineyards he worked with were conceived by him and his clients from the ground up, including site selection. The "integration" refers to understanding of all components of the vineyard: soils, water, climate, plant materials: variety, clone and rootstock, trellis design, row orientation, etc. While he has taken over the advisory function for numerous vineyards, he prides himself in the vineyards that he has started from the beginning.
Platt Vineyard
We visited Platt Vineyard, owned by Joan Platt and the late Lew Platt, with 30-plus acres planted on their hillside property located only about five miles away from the coastline at elevations ranging from 400 to 800 feet. The proximity to the coast (coastal fog is usually visible from the hilltops) may lead one to believe that fruit will not ripen in this vineyard. But while the site receives 1,700 to 2,200 degree days seasonally (2,050 average), the relatively mild climate (warm, but not hot days and cool, but not cold nights) has proven to successfully ripen the Chardonnay and Pinot Noir grown there. Roberts and his winemaker-clients believe that growing fruit on the "cool climatic fringe" provides the best expression of varietal character and creates the most interesting and flavorful wines. The vineyard's clientele bespeak of the quality of fruit being produced from this vineyard, now in its sixth leaf. Ramey Wine Cellars purchases the Chardonnay fruit from the 16 acres planted there. The 15 acres of Pinot Noir is purchased by Littorai Winery, Radio Coteau, Red Car Winery and Scherrer Winery. Additionally, there are two acres planted to rootstock that will be grafted over to Riesling.
The high-end vineyard began with a thorough soil survey. From that survey of potentially plantable areas, they found that some portions featured Goldridge soils while other areas did not. They felt that Goldridge soils would provide the highest quality and elected to plant only on those soil types. There are other seemingly plantable sections that were left alone. From the Goldridge sites, some soils were only 18 inches deep over sandstone. They were planted to Pinot Noir with a three-foot vine spacing and a six-foot row spacing. Other soils were deeper with no sandstone underlayment and Chardonnay was planted with a four-foot vine spacing. Rootstock choice was 420A and 3309, with the lower vigor 420A planted in sites with higher total available water.
The Chardonnay is entirely Wente while the Pinot Noir is a collection of clones including Pommard 05, 828, Calera, Swan and various Dijon selections. They have found that the smaller-clustered clones, like Calera and Swan, are the earliest to ripen and have the most promise from cooler vineyard sites, such as Platt. To manage the larger-clustered clones, such as Pommard and 828, fruit is thinned down to one cluster per shoot.
Soil preparation involved the application of compost, gypsum and lime, the amounts determined from the soil analyses. The gypsum was needed to bind toxic aluminum, which is highly available in low pH soils. Soils were ripped to 24 inches using a winged ripper shank in the vine rows only. This creates a uniform soil depth for the vineyard while preventing soil structure degradation that can otherwise result from cross-ripping. The ripping was done with high precision using GPS-guided equipment accurate to within centimeters.
The narrow rows necessitate the use of crawler tractors to reduce soil compaction.
Minimal application of water and fertilizer
Roberts uses a minimalist approach to irrigation and fertilization management. The high density planting creates small vines that need only support a small amount of crop. This reduces the stresses on the vine for water as well as nutrients. Roberts feels that the smaller crop per vine has allowed him to manage the vineyard at a lower phosphorus level than in other vineyards. Phosphorus, commonly in short supply in low pH soils and in Goldridge soils, is difficult to manage in vineyards with "conventional" spacing and cropping levels. The vineyard is fertigated before bloom and veraison with small amounts of 3-18-18 fertilizer. The vineyard is moving towards organic cultivation. If nitrogen is needed, fish emulsion is applied through the drip. Potassium is supplemented with organic sulfate of potash. Phosphorus is applied with a 0-6-0 fertilizer containing phosphoric acid. The phosphoric acid is not CCOF- or OMRI-certified, but is accepted by the USDA as organic.
The irrigation levels are surprisingly low at this vineyard--almost no irrigation is applied, except for fertilization. For mature vines, between four and eight gallons are applied per vine per year. Leaf water potential does not fall below -11 bars, indicating a high level of water status. The cool, moist, coastal air combined with spring rains, mild temperature climate and high-density planting allows the vineyard to be nearly dry-farmed. During my visit in mid-July, the vineyard canopy was filled out and there was no indication of water stress.
Training, pruning, canopy and yield management
The vineyard is entirely cane pruned to a double Guyot system on a vertically-shoot-positioned (VSP) trellis. The Guyot system is two canes positioned in opposing directions from the head with no renewal spurs. While the lack of renewal spurs is seemingly risky, there did not seem to be any problem getting two strong shoots from the basal buds of the cane to be used for the following year's canes. Eliminating renewal spurs creates a more open environment in the head of the vine, which can otherwise become congested with fruit and foliage. Looking at the vines, I was impressed by how uniform and open the fruit zone was. Roberts aims for a shoot density of three shoots per foot, which is a lower density than is used "conventionally" (i.e., 4.5 shoots per foot). With a low shoot density, no leaf removal is necessary. Only laterals are removed to keep the fruit zone open.
Uniformity is crucial for a high-end vineyard (or any vineyard). The short canes used in this vineyard produce uniform shoot growth from each bud. Fruiting height is 30 inches, although Roberts told me that they are now using a 24-inch fruiting wire. This will allow them to maintain a full VSP canopy with only 6-foot trellis stakes.
Yield is largely managed by controlling shoot density. Looking at the fruit zone, it is apparent that the clusters are evenly distributed and are not even touching one another. However, a green fruit drop is conducted at about 80 percent veraison. In some Pinot Noir blocks, individual green berries are removed to promote uniformity of maturation.
Yields from this vineyard have been about 1.5 tons per acre. They are shooting for no more than two tons per acre on the Pinot Noir. You are probably wondering if this is an economically feasible business model. I chose not to inquire about grape prices, but Roberts offered that the economics of this vineyard are sustainable and that it is likely to at least break even every year.
Winemaker buy-in
Platt Vineyard, like Roberts' other vineyard projects, is being managed with the wines in mind, not just the grapes. I spoke to some of the winemakers who purchase fruit from this vineyard and their enthusiasm was clear. Carroll Kemp of Red Car Winery said that one can make good wines elsewhere and with less attention to viticultural detail, but one cannot make the very best wines in that manner. He feels that climate is the single most important site factor and looks for sites that are on the cool climatic fringe for each variety. Fruit from Platt Vineyard goes into his top blends. For his second label (his Box Car brand), he looks for vineyards of similar climatic character but allows more wiggle room for viticultural practices. Fred Scherrer of Scherrer Winery stated that some vineyards and wineries pay lip service to quality but often cut corners. He says that none of that occurs at Platt. He appreciates the attention to detail that went into the vineyard, from site evaluation to soil preparation, planting, training and ongoing management. He was clearly excited by the fact that fruit could be harvested based solely on flavor maturity without the need for worrying about high sugar levels.
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The new and old at Zio Tony |
While Platt Vineyard serves as a shining example of Roberts' viticultural style, he works with many others, sometimes developing vineyards and other times retrofitting them to produce higher quality fruit. In the Russian River Appelation's Martinelli Zio Tony vineyard, Roberts pointed to the contrast of the "old and new" styles of vineyard establishment. The old Chardonnay vineyard block was planted with an East-West orientation on a split cordon Lyre trellis and on AxR#1 rootstock. The vines are large and difficult to manage. Fruit on the north side is perpetually shaded while fruit on the south side is sunlit. This creates an imbalance in fruit character and maturation. Roberts designed the new Chardonnay block, across the avenue, with a North-South orientation, a VSP trellis and on 3309 rootstock. Additionally, two drip lines were installed in the vineyard from the beginning. The second line may be used to irrigate replacement vines or to treat any weaker areas differently than the remainder of the block. The difference in the two blocks was clear--take a look at the photos.
Benovia Winery purchased an existing Russian River vineyard that had two blocks of cordon trained Pinot Noir 05. One was spaced at 8x8 feet and the other at 4x4. While both vineyards produced high quality wines, their winemaker Mike Sullivan told me that they felt that the higher density vines produced more of what they were looking for. Mike stressed that uniformity in the vineyard was the primary factor for the production of high-end wines. The smaller vines tended to produce fruit that matured more evenly within each vine and across the vineyard. Mike believes that the vineyard must be developed and maintained at every step with uniformity in mind. To that end, they are engaging in new plantings of high density vines, taking the same painstaking measures as had been done at the Platt Vineyard.
Perhaps most vineyards will not be farmed using the Integrated Winegrowing approach. But, these vineyards serve as great illustrations of the concepts that maximize the varietal expression of a vineyard: varietal/climate suitability, smaller vines, low water and fertilizer inputs, uniform canopies and synchronized fruit maturity. wbm
