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Factors Affecting Vineyard Site Suitability in Cold Climates Such as Found in New York State |
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The most fundamental and irreversabile decision in the life of a vineyard is the choice of site. In warm/temperate regions the decision may be largely a matter of cost, proximity to markets, labor supply, availability of water, etc. The decision will influence the profitability of the vineyard. In a cold temperate region such as New York, the same factors need to be taken in consideration, but idenfying a site where the vine can grow and mature is crucial to the very survival of the future vineyard.
Once the limits of the site are identified, additional questions regarding variety, rootstock, vine and row spacing or needed corrective pre-plant action may be made, but the answers to the latter questions are site specific. They are only valid for a particular site.
Grapevines need:
A growing season of sufficient length The growing season is by the number of days between the last 28°F in spring and the first fall occurence. The season at a particular site must be long enough to allow both the fruit and the vegetative parts of the vine to mature. It must provide enough heat energy to ripen the fruit and vegetation.
There must be adequate sunlight hours to ensure a sufficient supply of carbohydrates are produced by photosynthesis to mature the fruit and vine and to maintain future productive potential.
The supply and the availability of essential mineral elements in the rooting zone must neither be inadequate nor excessive. Mineral elements which are not essential may also be problematic if they are toxic to grapevines or consumers.
There must be a steady and sufficient supply of water to allow the vine to function properly. However, soil water must not be in excess or grapevine roots will suffer. Often in cool or cold climate production regions the vines are not irrigated. In that case the soil must retain enough water in the root zone to provide vine needs between rains.
The site should neither receive nor retain excessive moisture, and it should allow cold, dense air to drain away from the vineyard. Otherwize cold injury or water logging may occurr. However, surface water and air drainage should not be obtained at the cost of increased soil erosion or limitations on the ability to operate machinery safely.
Factors which influence the supply of heat and light energy:
The macroclimate is the climate of the greater region (e.g. northeast, Great Lakes)
The mesoclimate is the climate of the site in question (e.g. these 10 acres on the west side of Canandaigua Lake)
The microclimate - the climate of the grapevine itself.
The Goals
| 1. Identify and correct factors which might limit vine function. | |
| Latitude | How far north is the site? This will largely determine the heat and light energy supply and length of days and of the growing season. |
| Longitude | Important only in that it may indicate the degree of water moderation |
| Elevation | An increase in altitude has the same effect as an increase in latitude |
| Slope | Determines amount of air and water drainage, but also what machinery may be used and the degree of erosion hazard |
| Aspect (orientation) | Sites with northern exposures receive less light in northern latitudes than sites with other aspect. Although southern slopes are often sought, the benefit is greatest only with steep slopes at very high latitudes |
| Continentality | Extent to which the macro- and meso-climate is not influenced by large bodies of water. Major grape production regions tend to be located on the lee (western in the northern hemisphere) shores of the oceans. The Great Lakes are important modifiers of New York's macro-climate . The Finger Lakes provide only local relief, but do provide a place into which cold air may drain. |
| 2. Below ground factors - healthy roots require | |
| Oxygen | Free drainage of internal water - affected by texture, impermeable layers and water table depth |
| Water supply | Oxygenated soil depth and soil bulk density determine potential rooting depth. Soil texture influences soil bulk density, water drainage and water holding capacity. In areas with summer rainfall the combined effects of these factors determines the amount of water which will be available to grapevines between rains. |
| Mineral nutrient balance and supply | The nature and amounts of the various mineral elements available for grapevines is affected by soil pH, texture and parental material. |
| If low temperature is higher than | Injury hazard is | Suitable Varieties |
|---|---|---|
| 0°F | very low | almost any |
| -5°F | low | most northern vinifera |
| -10°F | moderate | hardy vinifera/moderately hardy hybrids |
| -15°F | high | hardy hybrids/most American |
| <-15°F | very high | hardy American varieties |
Take me to vinifera varieties for cold climates
Take me to grape varieties for cold climates
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Go to NY Map with Cold Isotherms The map shows expected minimum temperatures in NY. Note the relationship between large bodies of water (Lake Erie, Lake Ontario and Long Island Sound) and the expected cold temperature. The topography is also important. The low elevation sites in the Finger Lakes and the Hudson Valley are warmer than the adjacent highlands |
Cardinal temperatures
Growing Degree Days (GDD)- are an attempt to quantify heat available for vine development during the growing season. By convention grape degree days are tallied between April 1 and October 31, and a base temperature of 50°F is used.
| GDD = Sum of ( | (Daily Max Temp - Min Temp) 2 |
) -50) for all days April 1 to Oct 31 |
The book "General Viticulture" by Winkler et. al. defines five grape growing regions based upon seasonal degree day accumulation.
| Region I | <2,501 degree days | Winkler suggests early ripening varieties achieve high quality |
| Region II | 3,501 to 3,000 degree days | Most early and mid-season table wine varieties will produce good quality wines. |
| Region III | 3,001 to 3,500 degree days | Favorable climate for high production of standard to good quality table wines. |
| Region IV | 3,501 to 4,000 degree days | Favorable for high production, but table wine quality will be acceptable at best. |
| Region V | >4,001 degree days | Usually only table grape varieties desitined for early season consumption are grown. |
| Latitude | Seasonal Degree Day Accumulation (50°F base) | |
| Reims, France (Champagne) | 49° 20' | 1,756 |
| Zurich, Switzerland | 47° 23' | 1,874 |
| Würzburg, Germany | 49° 48 | 1,908 |
| Dijon, France (Burgundy) | 47° 15' | 2,084 |
| Genève, Switzerland | 46° 12' | 2,090 |
| Roseburg, Oegon | 43° 20' | 2,115 |
| Penn Yan, New York | 42° 30 | 2,390 |
| Bordeaux, France | 44° 50' | 2,464 |
| Geneva, New York | 43° | 2,519 |
| Fredonia, New York | 42° 30' | 2,531 |
| Keckskemét, Hungary | 46° 54' | 2,588 |
| Cutchogue, NY | 41° | 2,676 |
| Canberra, Australia | 36° | 2,714 |
| Bolzano, Italy | 46° 30 | 2,985 |
| Glenham, New York | 42° | 2,992 |
| Udine, Italy | 46° 04' | 3,168 |
| St. Helena, California | 38° 30 | 3,302 |
| Fresno, California | 36° 40 | 4,684 |
Winter, spring and fall cold cold is the major limitation to successful vineyard establishment in New York state. Factors which favor success include low elevation, proximity to large bodies of water and adequate soil and above ground air drainage. Limited soil depth or internal soil water drainage is incomaptible with vine productivity. Poor drainage may often be improved by installation of drain tile. Irrigation will help allieviate the effect of shallow soil, but only to a limited extent.
In addition to affecting the meso-climate, the nature and properties of the soil will determine nutrient availability. Grape species are adapted to different soil types, and the adapatation of specific varieties or classes of grapes to a given soil is important. (Go to Vineyard Soils)
In New York state, local information and advice on climate and soils can be obtained by consulting with county or regional Cornell Cooperative Extension offices or with a regional USDA Natural Resouce Conservation Service Office (formerly Soil Conservation Service)
© Copyright 2000 Robert Pool