How Does a Vineyard Actually Work?

The infrastructure of a working vineyard

If you enjoy the mechanics of a vineyard, then here are the gory details about some of the major elements of a vineyard

Grape Vines
Since the only family of grapes (vitus) capable of making fine wine (vinifera) – is susceptible to a variety of diseases native to North America (phyloxera), grape vines are grafted to rootstocks from crosses of vinifera and native grape varieties resistant to those diseases. Thus almost every mature grape vine is a vinifera plant grafted onto a rootstock. I feel obligated to mention that there are other species of grapes from which wine can be made, and east of the Rockies you can find them made in a wide variety of places. But in California, Vitus Vinifera is King (Queen?).

There are several ways to graft that fall into two basic categories – First is field grafted or “budded”. The rootstocks are planted and the following year a “bud” from a vinifera plant is grafted onto the rootstock in the field. Second is bench grafted where the rootstock and vinifera materials are mechanically grafted together at the nursery. The nursery raises the vine and the resulting plant is either sold “green” over the summer or “dormant” the following spring. Prices run $2.50 to $3.50 a plant depending on the source of the material. The reasons you might choose one system of another depends on your timing and your management beliefs.

Once in the ground and growing grape vines don’t need much care compared to most agricultural crops. In fact, wine grapes praticularly use less water, less pesticides and less fertilizers than most other cultivated crops. But they do have their needs:

Water
Protection from frost in the spring
Protection of pests and disease – particularly mildew
Some management of the canopy
Some fertilizer
The weeds within a one foot radius kept under control.

Irrigation
Young vines have to be watered. And quite a few mature vineyards need to be irrigated as well. In Sonoma County, vineyards are watered using drip irrigation that meters water right next to the vine. Usually one 1/2 gallon per hour emitter is used per plant. Since the spacing in the vineyard effects the number of vines per acre it also effects the gallons per minute required per acre. A typical modern spacing of 4′ x 7′ has 1500 vines to the acre. This vineyard would use 750 gallons of water per acre per hour or 12.5 gallons per minute per acre. Fortunately, irrigation can be done by block, so you won’t actually need 120 gpm to irrigate a 10 acre vineyard. But you get the idea of how much water you’ll require. A 40 gpm well would allow you to irrigate 3 acres. A 5 gpm well, more than enough for a house, won’t even irrigate 1/2 an acre and would require you to create 20 blocks to irrigate 10 acres. People get around the limitation of small wells by using large storage tanks.

Grape vines typically get 3 to 6 gallons of water a week from July through harvest or 6 hours once a week in the system described above. More during heat spells. Water is the only way to relieve heat stress. And more in their first year.

Vineyard drip irrigation systems are actually quite sophisticated. In order to achieve a relatively constant pressure in the system so that the emitter’s work correctly, the pipes are carefully size throughout the system. Mains and submain pipelines are buried beneath the vineyard and risers bring water up from the mains to each row.

Sophisticated filtration system are often used to make sure particulate don’t clog emitters.

Frost protection
Many areas of the county experience frost during the early spring. The emerging buds that form the first leaves are very susceptible to freezing. If they are killed by frost, they will not bear fruit this year. Bud break occurs sometime in March to April and the risk of frost usually ends around May 10th. 2001 and 2008 were very, very bad years for frost and many of my neighbors lost significant percentages of their crop to frost (30% to 50%).

So most growers that have the risk of frost protect their vines using one of three systems. The system that’s most obvious are the large vineyard fans that disturb the very cold air at the ground and hopefully mix it with warmer air above 20 degrees. These work down to about 28 or 29 degrees. Below that there is no warmer air to mix. Their other major drawback is that they are incredibly noisy and therefore not very popular among neighbors. They are said to sound like a 747 parked and running just down the road.

Probably the most common system is the user of traditional overhead sprinklers. By setting up a grid of regular lawn sprinklers set on top of pipes that cover the entire vineyard you can use the water to protect it. How? Water generates a minute amount of heat at the point of freezing. As long as water continues to be applied and continues to freeze, the plant will stay just above 32 degrees. If the water stops before the ambient temperature is above freezing, its all over. The draw back with this system is that it uses a prodigious amount of water – almost always requiring a pond or lake to draw from.

The third and most modern system is micro-pulsating-sprinklers. These are very small sprinkler heads, similar to those used in household drip irrigation systems, they spray a narrow pattern (like a bowtie) just over the vines. They use a fraction of the water that the standard overhead system uses and can be run by large wells for small to medium sized vineyards. Their down side is that they require a lot of maintenance and have to be started at much higher temperatures (OK, it’s a little detailed, but I can’t let that go unexplained. You have to get moving water onto the plants before the temperature reaches 32 degrees or the water in the hose will freeze rendering the system useless.

Water – wells and ponds
Where does this water come from? If you are really lucky, it comes from treated waste water. If you are just lucky, then it comes from well water or an existing pond. If you are unlucky, you’ll need to build a pond. These are issues that make or break a property purchase decision. There is no way around the need for adequate water.

If there is no well on the property. Don’t take anyone’s word for the presence of adequate water. The first step is to look at the water your neighbors have – they will give you the best indication. If you enter into escrow on land with no developed water, make exploring for water part of you inspection process. This can be expensive and often the issues of buyers being reimbursed if no water is found are often contentious.

Power
Moving water requires large pumps and large pumps require power. Now it is possible to power a small to medium vineyard with diesel or propane generators, but it takes an usual level of dedication to a piece of property to pull it off. Most of us need good old fashion three phase power. Three phase power you say. You didn’t know power came in different flavors? Most houses run off single phase power. But most commercial operations and most large pieces of equipment require three phase power.The 10 acre vineyard we were talking about with micro-sprinklers that use 18 gpm per acre would require a pump capable of delivering 180 gallons per minute. That’s a big pump (more than 20 horse power) and not available in single phase.

We ran into that problem on our place. There was power to our house and the adjacent vineyard well when we bought it. The pump in the well was putting out about 40 gallons per minute – not really enough for the vineyard that had been installed.. The 6″ casing down the well should have allowed us to get 100 gallons per minute. But the power lines to the house carried only single phase. The largest single phase pump available was already down the well. To increase the production of the well, we would have had to bring three phase power the entire 1/4 of a mile distance from road to house. It turned out to be cheaper (and still damned expensive) to drill a new well next to the road where three phase power was readily available. It also allowed us to drill an 8″ well that provides 350 gpm for frost protection.