Ahead of the curve
Phil Coturri has been growing organic wine grapes in Sonoma for 25 years, and 10 years ago helped set the trend for organic olive oil production in California. For both crops, his management principles center on diverse cover crops, composts, careful use of irrigation and constant attention to the flavors of the final product.

By Henry Homeyer
Posted January 27, 2005


Photo by Henry Homeyer
The Sonoma Valley of California, an hour north of San Francisco, is world renowned for its vineyards. It is picture-postcard beautiful, with roads that wind through the hills, offering long views and glimpses of rural tranquility. But it is also an area of intensive agriculture, each acre of vineyard producing thousands of dollars of value--which are needed to pay the high cost of taxes and labor in the area. Real estate has become so valuable that most farmers wouldn't even think of starting a new farm there.

For the past 25 years Phil Coturri has been growing grapes and managing vineyards using nothing but organic techniques. Sixteen years ago, he bought 20 acres of land near the end of a winding dirt road in Sonoma where he grows not only certified organic grapes, but also organic olives for oil.

Phil runs a management company, Enterprise Vineyards, which grows grapes for Coturri Winery and for other winemakers in the area who are no longer willing to have fungicides, herbicides and insecticides sprayed on the grapes they use to make wine. Phil's brother Tony makes the wine at Coturri Winery.

[Phil] likes the pea blend because in addition to fixing nitrogen in the soil, it has a long bloom period, which attracts beneficial insects. Not only that, he says, "I like to walk the vineyard in winter and just graze on them."

Part of Phil Coturri's success with his wine comes from his lean rocky soil. He does not believe in fertilizing the grapes with any type of bagged fertilizer, even organic ones. He feels it promotes fast growth which makes the plants more susceptible to insects and diseases and compromises the flavors of the wine.

Instead of using fertilizers, Phil uses cover crops. Most of the grapes Phil tends are on steep hillsides that have been terraced. In new fields, Phil plants a mixture of plants to establish a permanent nitrogen-fixing cover, which also helps to minimize erosion.

Included in the mix are annual bell beans at a rate of 60 pounds/acre, supplemented by 40-60 pounds of peas/acre. The bell beans are similar to fava beans, but smaller. The peas he plants are a blend of Biomaster pea, Austrian pea and Mangus pea. He likes the pea blend because in addition to fixing nitrogen in the soil, it has a long bloom period, which attracts beneficial insects. Not only that, he says, "I like to walk the vineyard in winter and just graze on them."

In addition to the peas and beans, Phil plants 20-30 pounds/acre of a cereal grain- either barley, wheat, white oats or Cayuas oats. This he mows and lets decay, allowing the organic matter to break down, improving tilth.

Mustard is very beneficial, according to Phil, because it has a deep tap root to break up compacted soil. It also has nematicidal qualities, repelling or killing nematodes. He plants a proprietary mustard known as Mustard Caliente. It starts blooming in February and blooms for 2-3 months. He plants 5-7 pounds of mustard per acre.

A reasoned approach to pest management

One conventional vintner ... sprays his grapes at night because he doesn't want consumers to see him spraying: "It's bad for business," he said. But Phil Coturri has always been organic, and he has done just fine without them.

Most wine growers panic at the thought of mildew or molds, and chemical fungicides are considered a necessary evil. One conventional vintner I interviewed sprays his grapes at night because he doesn't want consumers to see him spraying: "It's bad for business," he said. But Phil Coturri has always been organic, and he has done just fine without them.

Part of Phil's strategy has involved knowing just how severe the mildew pressure is during the season. He purchased a high-tech weather station that keeps track of temperature and humidity levels. When temperature and humidity climb to a certain level, he takes action.

Phil has three measures he can take. Probably the most effective anti-fungal he uses is Serenade, a biofungicide. It is an OMRI-approved, patented strain of a bacterium, Bacillus subtilis. It stops spores from germinating, disrupts growth of fungal germ tubes and mycelia and inhibits attachment of pathogens to the leaf. It does not adversely affect insects or other non-target organisms, has a zero-day pre-harvest interval, and a four-hour re-entry period.

He also uses stylet oil, which serves as a suffocant for powdery mildew. His spray rigs are equipped with micronized sprayers that will blend 1 gallon of JMS Stylet Oil with 50 gallons of water.

Elemental sulfur, approved for organic growers, is another tool Phil uses, albeit reluctantly. He uses it as a dust at a rate of 10 pounds/acre. It is particularly effective in getting mildew that lies dormant on the stems of the grapes. Although elemental sulfur is approved for use by organic growers, it is still very powerful, and Phil buys top of the line respirators for his applicators--at a cost of $1,000 each. And he and his workers stay out of sulfur-sprayed fields for 48 hours.

Although some organic farmers believe that aerobic compost tea can be used to control mildews and molds, Phil says his grapes are too high in value to depend on it. He believes that compost tea has a valuable role to play, however, particularly in inoculating new soils, or in fields that are in transition from conventional to organic. "I want to get as much inoculant out here as possible," he said. He uses it for fertigation, and sprays it on cover crops, his grape vines and olive trees.


Photo by Henry Homeyer
[Phil] uses Landani tractors, a small Italian make that can easily negotiate the terraced hills of vines to mow down the vegetation. But there is no substitute for hand labor. In peak season he has up to 50 farm hands...

Phil has a 50 gallon "Growing Solutions" compost tea brewer, and consults with Dr. Elaine Ingham, the compost tea guru from Oregon (www.soilfoodweb.com). He purchases compost from Earthbound Compost of Bodega, Calif. Their compost is largely derived from dairy manure.

In his tea, Phil uses earthworm castings, minerals, and Microphos, a finely ground soft phosphate. His soils tend to be low in phosphorous, he explains, and grapes need phosphorous to ripen properly. He has found compost tea to be a good way to deliver it to the plants on time. Over the winter he plans to set up a 200-gallon brew tank.

Weeds are a problem for any farmer, but probably less so for Phil than for many because he has kept them under control for decades, not allowing them to go to seed. Unlike many grape growers, Phil does not believe in a "bare earth" approach to growing. He knows that cover crops compete successfully with weeds, if selected and used properly.

He uses Landani tractors, a small Italian make that can easily negotiate the terraced hills of vines to mow down the vegetation. But there is no substitute for hand labor. In peak season he has up to 50 farm hands, each of whom carries a shovel or a hoe to slice off noxious weeds when they appear. He sees no advantage in using herbicides, even ones approved for organic production.

Doing the math

Phil Coturri manages about 400 acres of grapes each year, producing 2-3 tons of grapes per acre. Eighty percent of the grapes are sold to small, upper-end wineries that produce wines in the $20/bottle range, although some of the better ones sell for $50/bottle.


Photo by Henry Homeyer
According to Dan King, wine manager, Coturri syrahs and merlots are "the richest and most flavorful organically grown wines I have sampled to date..."

Developing new acreage for vineyards in this hilly valley costs $80,000 to $100,000 per acre, over and above the cost of land. This includes clearing, terracing, and installing irrigation systems. The annual costs of growing grapes run $5,000 to $7,000 per acre. But each ton of grapes produces about 60 cases of wine, or 720 bottles. In a good year, each acre can gross up to $40,000 worth of wine on the retail market.

Coturri Winery produces reasonably priced organic wine that is so good they don't even have to label it as organic. Buyers want it because of its rich, complex flavors. It was recently the "buyer's choice" at the wine department in our local food cooperative in Hanover, N.H.--a store that sells 200 wines or more. According to Dan King, the wine manager, Coturri syrahs and merlots are "the richest and most flavorful organically grown wines I have sampled to date. They are not delicate or refined, but very good nevertheless. They are meant to drink now, as they have no [added] sulfites."

A California olive oil pioneer

In addition to growing wine grapes, Phil Coturri grows olives for olive oil. Never one to do things by halves, in 1994 Phil imported 15,000 olive tree cuttings for propagation. He got them from Tuscany, Italy, where the climate is similar to that of the Napa Valley.

Within three years he had propagated 100,000 olive trees and sold them to farmers all over California, including many other wine grape growers. Wineries like Jordan and Klein planted them and began selling olive oil in their tasting rooms.

SLIDE SHOW: Coturri Olives

One of the initial difficulties facing Phil and other olive oil producers was the lack of processing equipment. There was just one mill willing to do custom pressing. Before long, however, supply followed demand, and now there are at least half a dozen olive oil mills working with area growers.

At first, olives were a trouble-free crop here. But four years ago the Mediterranean olive fruit fly appeared in California, and within two years it found Phil's olives. "That year it decimated crops and I didn't know how to deal with it. I'm an organic farmer. I've always been an organic farmer. But if I'd had an atom bomb, I'd have used it on them," Phil said.

"That year [the Mediterranean olive fruit fly] decimated crops and I didn't know how to deal with it. I'm an organic farmer. I've always been an organic farmer. But if I'd had an atom bomb, I'd have used it on them,"

Phil has used a couple of different approaches to the problem. First, he uses traps. He uses the sepia trap, which is a bottle with water and some yeast in it. It has small holes in the sides, so the flies go in but can't get out. This is a labor-intensive way to catch fruit flies--especially since Phil has 4,000 olive trees that he tends (both his own and for other people).

Phil now uses an insecticide for fruit flies produced by Dow AgroSciences that is OMRI-approved for use by organic farmers. The insecticide is called GF-120 NF, and contains something called spinosad. Spinosad is produced by growing a soil actinomycete (Saccharopolyspora spinosa) on a medium, and fermenting its byproducts using a specific bacteria. The result is then processed and turned into a highly concentrated conventional aqueous suspension.

Spinosad is mixed with a bait made of sugar and a protein byproduct of corn, attracting the fruit flies which ingest it. It is very fast acting: according to a University of Minnesota article, cessation of feeding and paralysis occurs within minutes. Phil explained that they don't have to spray every tree; just a 3-foot circle of spray on the foliage of every other tree will do the job.

The good news is that spinosad is not toxic to bees and other beneficials in the doses used. According to the USDA, spinosad has not shown any evidence of carcinogenicity in mammals, and reproductive or developmental toxicity only occurs at exposures much greater than those which could occur from applications of spinosad bait spray.

According to Dow AgroSciences, spinosad was the winner of the 1999 Presidential Green chemistry Challenge Award. Various other spinosad products have been EPA-approved for use on cotton, vegetables, flowers and stonefruits.

Spacing, fertility, and climate

Phil plants his olives so that each tree has a 12 foot by 12 foot space, which translates to 200 trees per acre. He explained that some producers are now keeping trees very small for ease of harvesting, and are growing on 6' by 8' or even 4' by 8' spacings.

Around each tree Phil creates a donut of compost about four feet in diameter and four inches deep. This keeps down the weeds close to the trees and adds organic matter to the soil. He then mows between the trees to keep weeds down.

As with his grapes, Phil does not believe in using bagged fertilizers on his olive trees. He feels his trees get more balanced growth from nitrogen-fixing cover crops. And he believes that the more they struggle, the better the flavor.

As with his grapes, Phil does not believe in using bagged fertilizers on his olive trees. He feels his trees get more balanced growth from nitrogen-fixing cover crops. And he believes that the more they struggle, the better the flavor. If you add nitrogen, he said, their growth is flabby and more susceptible to frost or other problems.

Phil does use rock dusts as a soil supplement, however, both on his grapes and on his olives. Silicaceous rock powders are believed by many farmers to mimic the remineralization that occurs when glaciers descend from the north, grinding rocks into a fine powder that supplies trace minerals. Scientists have been unable to explain the exact mechanisms by which rock powders work, just as they are unable to explain how biodynamic preparations or radionics influence crops.

The rock dust Phil uses is very fine--probably about 200 mesh screening. He gets it from Arizona in one-ton bags. The micronutrients in the rock dust are thought to be important for developing resistance to stresses like cold and drought. Phil uses 300 to 400 pounds of rock powders per acre on both his olives and in the vineyards.

The hardest part of working with rock powders is deciding how to apply them. Sometimes during the growing season Phil will coat the trees using a standard dust applicator. Or he will mix it in with compost and add it on top of the soil around trees or vines.

Frost can be a problem. Olive trees withstand temperatures down to 28 or 29 degrees, but freezes in the low twenties can do serious damage. That is another reason Phil avoids fertilizers, since fast growth is more susceptible to frost damage. His olives are not grafted varieties, but grow on their own root stocks—so that if a severe cold snap kills the top of a tree, it can come back from its roots.

Irrigation is used minimally. Olives are very drought resistant, so Phil waits until after the fruit has set before he adds any water. He uses a drip irrigation system to avoid wetting the leaves, which could promote the growth of fungi. Depending on the weather, Phil provides 25-40 gallons per tree per week late in the season.

It all comes down to taste

Phil and his wife Arden were some of the original members of the California Olive Oil Council, and she is now a certified taster. She explained that there are 25 tasters, and that they get together to judge olive oils, deciding if an oil is extra virgin or not. A minimum of eight tasters meet at any one time. "We are trained to detect defects," Arden said. "We are just beginning to start another realm of tasting - to detect different flavors." She explained that Mission olives taste totally different from Tuscany olives, for example. The Board's labeling is primarily a marketing tool.

Phil makes oils from a mixture of green and ripe olives. This produces rich, pungent oils, although in smaller quantities than from green olives alone. He likes to start picking in late October when there is a 50-50 mix of green and ripe olives on the trees.


Arden and Phil Coturri
Photo by Henry Homeyer
"We're getting olive oils that are world-class olive oils. You come home and have oil that is within 12 hours old. There is nothing like the flavor of fresh-pressed olive oil."

There are as many varieties of olives as there are of apples, according to Phil. They blend their oils out of different harvest lots so that the flavors become richer and more complex.

Last year Phil harvested between 1 and 2 tons of olives per acre. Each ton of olives yields between 20 and 35 gallons of olive oil. He packages it in 350 ml bottles, which sell for about $10 each. Even so, according to Phil growing olives "is the pursuit of a passion more than common sense," since they cost $500 per ton to harvest.

Another advantage to growing both olives and grapes is that it allows him to keep his workers busy all year round. The olive harvest falls after grape harvest, during a period of time when he'd otherwise have nothing for his workers to do. He has a loyal and hard-working crew, and would hate to lose them by laying them off. So, he said, even if the olives are just a break-even proposition, they're worth growing.

Phil loves what he does. He's proud of the wines and olive oil that come from his fields. He loves having both on his table every night. "We're getting olive oils that are world-class olive oils. You come home and have oil that is within 12 hours old. There is nothing like the flavor of fresh-pressed olive oil." Having sampled both his oil and his wine, I agree: he should be proud.