Organic vs. Sustainable Farming
Steve Pride
August 27, 2025

Wine enthusiasts want to be drinking wine that is free of unhealthy chemicals, made from grapes grown in a way that does not harm the natural environment. Collectors are led to believe their choice is between wines made from grapes that are either “industrially farmed” or “organically farmed” with it understood that organic farming is better for the environment and produces wine that is healthier for you. The actual story is more nuanced and interesting. 

The idea of “industrial grape farming” is that large farming operations want to produce grapes with large yields in as cost-effective manner as possible, so they use synthetic chemicals to reduce labor costs without much concern for the environment. The idea of “organic grape farming” is that only naturally occurring chemicals can be used on the grape vines. The idea of “sustainable farming”, at least as defined by me, is to employ strategies that result in the best long-term health of the vines, soils, workers, customers and overall biological and physical environment, regardless of the work effort, cost or any marketing concerns. Let’s explore these distinctions.

In California, it does not rain in the summer, so grapes require drip irrigation to grow and be healthy. Once you start to drip water onto the ground under the vines, weeds start to grow. Because growers want the water to be used by the grapevines and not the weeds, one standard industrial practice is to use Round Up (glyphosate) to kill the weeds that are growing under the dripline prior to the start of the vine’s shoot growth in the spring. Glyphosate can then get into the grapevine and ultimately into the grapes at trace amounts, and nobody wants that chemical in their wines even at concentrations as low as parts per billion. To not use glyphosate, you must design a weed control program that will always be much more expensive and time-consuming. One easy, though expensive, approach is to rent sheep and a shepherd to remove the weeds for you.  But sheep are selective and do not eat all types of weeds that grow in a typical vineyard. The best weed-control approach that we have found at Pride Mountain Vineyards is to use a weed knife under the driplines. This is a blade pulled just under the soil by a tractor that avoids making contact with the vines and that works best when there is still some moisture in the soil. We then follow that up as needed with shovels once the soils dry out and we begin to irrigate the vines. It is a lot of work each year, but we get the desired result of controlling weed growth under our driplines without the use of industrial herbicides. 

Another topic is each grower’s fungicide spray program. This is the place of greatest confusion among wine writers, sommeliers and the wine-buying public. If you do not control the various types of fungi that grow on your grapevines throughout the growing season, the leaves will not be healthy for photosynthesis, and the clusters can completely wither or be otherwise unsuitable for the making of fine wine. Organic farming requires the use of natural minerals and bio extracts as fungicides that are made without synthetic chemicals. The two dominant minerals that are certified “organic” and that are the most effective for killing fungi are sulfur and copper. Copper sulfate is usually combined with hydrated lime and put into a water solution prior to spraying onto the vines. Because the copper sulfate makes sulfuric acid in water, the lime is added to partially neutralize the acid so that the solution does not damage the vines. Typical rates are to apply the copper sulfate at 5 to 10 lbs per acre of vines. Sulfur solutions are made by combining dry elemental sulfur with water at rates of 5 to 10 lbs of sulfur per acre for spraying.  Later in the growing season, the elemental sulfur is applied as a dust at a rate of 10 to 15 lbs per acre. There is no maximum EPA limit on the amount of sulfur that can be applied to an acre of grapes in one year, but copper sulfate must not exceed 80 pounds per acre per year. A common organic spray program would be to apply sulfur three times per year, copper twice per year, and a horticultural oil such as “stylet oil” (an almost pure paraffinic mineral oil) an additional one or two times per year at rates of say 2 gallons (or 17 lbs) per acre and possibly some additional sprays involving good fungi.

The damage to the environment due to regular use of both sulfur and copper can be significant. Sulfur sterilizes most organisms it comes into contact with, including the myriads of beneficial insects in a vineyard that keep harmful insect populations under control, some of which are involved with the spread of virus throughout the vines. Maintaining a healthy beneficial insect population is a primary objective of our viticulture program here at Pride Mountain Vineyards because it effectively eliminates the need to use insecticides for problem insects. If you want to maximize biodiversity and have a thriving healthy insect population on your property, you cannot be using extensive amounts of sulfur each year, especially later in the growing season. Horticultural mineral oils are also harmful to many beneficial insects such as ladybugs. Copper is a heavy metal that builds in the soils if used multiple times per year over many years and begins to kill the microorganisms that make up a healthy soil.  In particular, the good fungi that live on the hairs of vine roots are what allow water and mineral nutrients to enter the grape vine.  As copper accumulates in the soil, it eventually kills these good soil fungi, resulting in less-than-healthy vines and soil. If you limit the use of sulfur and copper to no more than once per year and in the early part of the growing season, not much damage to the environment will occur.  But a single application of each will not be sufficient to keep mildew under control through to harvest.  

Such “organic” practices can be compared to using synthetic chemicals that are designed to target one specific mode of fungal biological activity like reproduction or respiration. Each targeted mode of fungal metabolism is given a “FRAC” number by the international “Fungicide Resistance Action Committee”. If a spray program targets the same mode of fungal activity repeatedly throughout the year, a fungus will build resistance to that treatment mode. But there are something like 20 different FRAC modes (numbers) that can be targeted to eliminate specific problematic fungi in vineyards. In a well-designed spray program, you target a particular fungal-metabolic mode no more than once per year. 

Here at Pride Mountain Vineyards, we typically need to apply a fungicide spray 7 times per growing season to keep the vines and grapes in maximum good health. Our goal with the program is to enhance biodiversity in our soils, maintain healthy beneficial insect populations and to put the least possible pounds of chemicals, organic or synthetic, onto our vineyards each year. We begin the growing season with one organic sulfur spray prior to when the beneficial insect populations have grown significantly, one copper spray while the soils are still wet with winter water, two organic “good fungus” sprays that promote populations of good fungi on the leaves and clusters that protect against problematic fungi and finally, we typically use 3 different sprays per growing season of a synthetic product used at rates of 0.25 lbs per acre that each targets a different fungus FRAC metabolic mode so that fungal resistance does not develop. These 3 distinct sprays and FRAC modes are changed from year to year, do no harm to the insect or soil microorganism populations and add up to a total of 0.75 lbs per acre per year to control mildew in comparison to using an additional 25 lbs of dry sulfur, copper sulfate or mineral oil per acre in order to be certified “organic”. An additional 25 lbs per acre of organic chemicals is, for me, a bludgeon that would create significant harm to our insect and good fungus populations and do environmental damage that I am not willing to sustain just to obtain the “organic” certification. We have created this fungicide program to promote soil health and prevent the sterilization of biodiversity, while still controlling mildew and mold on the vines. In addition to the above, we also spread mulches under the drip line each year that promote beneficial fungi in the soil while suppressing weed growth. 

A final aspect of farming is providing your vines with nutrients. Nutrient availability in the soil each growing season is different as influenced by the previous year, the amount of winter rain and temperature. The best way to know whether your vines have enough key minerals to promote photosynthesis and overall healthfulness is to collect leaves from each vineyard block and have them analyzed for the needed nutrient levels. The major nutrients required by all plants are the three listed on fertilizers: nitrogen, phosphorous and potassium.  But there is a long list of micronutrients such as iron, magnesium, boron, molybdenum, etc., that are important to nearly all plant metabolic processes and whose concentrations in the soils and vines naturally vary from year to year. Here at Pride Mountain Vineyards, we collect leaves from our 52 blocks of grapes and have them analyzed for nutrients twice per year, once at bloom in June and once at veraison in August. The measured nutrient levels are different from year to year with no two growing seasons ever the same. In vineyards making high-quality wine, nutrient levels are generally close to being right but always need some adjustments. Leaf-tissue testing is the only way to be certain that you provide your vines with just the right amount of each nutrient without overfeeding or underfeeding them. There is a real concern that if you just blindly give your vines lots of, say, nitrogen in order to maximize growth and green color, you may eventually pollute the ground water (which is at roughly 200 feet depth on our property) or acidify the soils. To avoid that while also achieving optimal vine health, you really need to go through the time-consuming process of measuring the nutrients in the leaf tissues of each block twice per year. Many of the most effective micronutrient foliar sprays are organic and quite expensive, so this practice of monitoring and adjusting nutrients is certainly not “industrial”. In keeping your vines just healthy enough, you allow them to better withstand heat waves, drought conditions and fungal pressure, which is key to the making of fine wine.

In summary, it is a lot of work to maximize the health of our vineyards, and we could not achieve the desired biodiversity outcomes to my long-term satisfaction if we were certified “organic”. Those are the conclusions that I have come to over decades of research and experience farming our property, but I understand that other farmers will come to different conclusions. 

We can call the type of farming we employ at Pride Mountain Vineyards as being “sustainable”. We do not ever employ herbicides or other “short cut” industrial practices that have the potential for harming our land and the people who work in the vineyards. Our 17-worker vineyard crew is the backbone to our success as a winery and our goal is to keep our property, workers and you, the customer, as healthy as we possibly can over many generations to come.