Site Selection

Vineyards are a long-term investment. Choosing an appropriate site for your vineyard is the single most important factor determining its economic success or failure. Success depends on choosing a site with appropriate climate, topography and soil characteristics. New York's variable climate, topography and soils limit where grapes can be grown, and what varieties are suitable for which sites.

A detailed discussion of factors affecting site suitability can be found at

Basics of Vineyard Site Evaluation and Selection, a part the New York Vineyard Site Evaluation System, an interactive, map-based site selection web site.

Climate Limitations

Grape growers in New York – and throughout the East – face an often-challenging climate. Although summer temperatures and rainfall distribution are comparable to northern growing regions in Europe, winter temperatures are lower. As a result, growers in every region of New York except Long Island have to cope with winter injury of varying severity.

Elevation and topography influence the length of the growing season, first and last frost dates, the amount of heat units that different areas accumulate, and air drainage. Extreme winter lows, late spring frosts, and lack of sufficient heat affect vine survival, yield, and the ability to consistently ripen grapes. Wine grape varieties vary in cold tolerance and in the length of season needed to consistently ripen them.

Before planting a vineyard, carefully evaluate both the macroclimate, or large-scale regional climate, and the mesoclimate – or site-specific climate as influenced by local topography, elevation, and proximity to bodies of water.

New York Macroclimate

Macroclimate in New York is strongly influenced by two Great Lakes, Lake Erie and Lake Ontario, and by the Atlantic Ocean, including Long Island Sound and the lower portion of the Hudson River.

In the western part of the state, the moderation from Lake Erie extends approximately 10-15 miles from the lake, up to the higher elevations on the Niagara escarpment. Lake Ontario buffers a larger area along the lake plain, and provides some temperature moderation to the northern part of the Finger Lakes.

In the Finger Lakes region, the larger lakes (Canandaigua, Keuka, Seneca, and Cayuga) range from 300 to 650 feet deep, and rarely freeze. Though much smaller than the Great Lakes, they provide local moderation of winter lows, and buffer temperatures at sites within a few miles of them.

New York Macroclimate and Site Suitability Maps summarize the geographical range of low winter temperatures, growing degree-days, and length of growing season in New York.

Mesoclimate or Local Climate

In addition to large-scale climate, local topography influences climate and site suitability on a local scale.

• Elevation. Average temperature declines with increase in elevation, so higher elevation sites are generally less suitable than lower elevation sites.
• Relative elevation. The relative position on a slope affects how prone it is to spring and fall frosts, because of air drainage. Cold air flows downhill, where it displaces warmer air. In mountainous areas, the middle elevations are often the warmest and least prone to frost injury.
• Slope and air drainage. Sloping vineyard sites promote air movement, particularly during radiational freezes, and are therefore less prone to both mid-winter cold injury and spring/fall frosts. Low areas within a vineyard are much more prone to frost injury, because cold air flows downhill and pools in low-lying areas. Even modest slopes (>2-3%) can produce significant air drainage and prevent early-season frosts.
• Aspect. Slope direction or aspect determines how much sunlight your vineyard will receive, and at what time of the day. Northerly slopes in general receive less solar energy and should be avoided - particularly in otherwise marginal climates. East to west -facing slopes are preferable. Where slopes are steep (>6%) and climates are marginal, planting on south-facing slopes may make grape production feasible where it otherwise wouldn't be possible.

Grape Varieties and Climate

A wide range of grape varieties are grown in New York and throughout Eastern North America, including:

• Vinifera, or V. vinifera types (cold-sensitive).
• Interspecific hybrids, also referred to as French hybrids (moderately cold hardy).
• Native American or Labrusca types (generally more cold-hardy).
• Cold-hardy hybrids, developed by University of Minnesota and private breeders, that survive down to -30F (very cold hardy).

They vary greatly in their tolerance to winter low temperatures, disease resistance, and length of growing season required to ripen them. The following table provides a general guide to the risk of winter injury for these different types of grapes:

If low temperature is higher than	Injury hazard is	Suitable Varieties
0ºF	very low	almost any
-5ºF	low	most northern vinifera
-10ºF	moderate	hardy vinifera/moderately hardy hybrids
-15ºF	high	hardy hybrids/most American
<-15ºF	very high	hardy American varieties
<-20ºF	very high	Cold-climate hybrid varieties

Table 1. Relative risk of winter injury for different grape cultivars for seasonal winter low temperature.
Originally developed by Bob Pool, and posted to the Cornell Grape Pages

Soil Characteristics:

Grapes are adaptable to a wide range of soil types, but soil characteristics such as internal drainage, soil texture, depth, water holding capacity and soil chemical characteristics such as soil pH will strongly influence growth, productivity, and quality.

Superior sites will have well-drained, sandy to gravelly or silty loam texture, allow rooting down to 1 meter, moderate water-holding capacity and soil pH ranging between 5.5 and 7.0. Most sites will have some soil limitations that may need correction.

Some common limitations are:

• Poor drainage greatly reduces growth and favors winter injury. Vine roots cannot grow, take up nutrients, or respire in water-logged soils. Seasonal water tables are often highest in the spring, which can delay growth and development. Saturated soils in the winter lead to more trunk injury, may increase the risk of crown gall, and warm up slower in the spring.
• Low pH restricts the availability of soil nutrients, leading to deficiencies and aluminum toxicity to roots.
• Low Water Holding Capacity, both in sandy soils and shallow soils, can lead to water deficits and drought stress.
• Shallow soils limit root growth and water availability, restricting vine growth.
• Root-restricting layers. Heavy clay soils or impermeable soil layers can restrict root growth, limiting vine growth.

Many of these soil characteristics can be modified before planting grapes.

• Drainage tile can compensate for poor internal drainage. Many vineyard sites in New York can benefit from installation of drainage tile.
• Preplant soil amendments can address soil pH and chemical composition, and modify the soil pH on a long-term basis.
• Irrigation can improve vine growth during establishment and compensate for overly-well drained sandy and gravelly soils or other soils with limited water holding capacity.
• Deep Plowing or ripping before planting can break up root-restricting layers.

Evaluating Soils

Soil Surveys. Information on soils can be obtained from soil surveys, available at local Natural Resources Conservation Service (NRCS) or Cooperative Extension offices. Digital Soil Maps are available online through the NRCS Web Survey.

Some characteristics in the soil description to look for include:

• Texture. Descriptive words denoting the proportions of coarse to fine particles (gravel, sand, silt, clay ) indicate general soil characteristics.
• Drainage Category. Internal drainage is categorized as 'poorly drained', 'somewhat poorly drained', 'moderately- well drained', 'well-drained' or 'excessively well-drained'.
• Soil pH. Native pH of surface and subsurface layers is quantified. In older surveys, soils are classified as 'high lime', 'moderate lime' or 'low lime' soils.
• Depth to Bedrock. A range of depths typical of the soils is given.
• Root-restricting layer: presence and depth of hard pans or other root restricting layers are given

The New York Vineyard Site Evaluation System will generate a soil characteristics report for any particular map location within New York State.

On-site Investigation

• Pre-plant soil tests will indicate chemical composition of the soil, including soil pH, macronutrients and micronutrients, and % organic matter. It is useful for indicating what amendments are needed before planting.
• Soil pits can be dug manually or by backhoe to look at soil characteristics on site. Look for rooting depth of existing plants, texture throughout the soil profile (possible root-restrictive layers) and the presence of standing water after digging. Augured holes can be filled with water and checked for percolation of water through the profile.

Summary

Site selection is important in determining the profitability and viability of any vineyard enterprise. Poor site selection and preparation lead to lower yields, more vine injury, unripe grapes, and higher management costs.

Determining your site's mesoclimate is the most important aspect of site evaluation. Many New York locations have short growing-seasons, low heat-unit accumulations, or other climate challenges that make them unsuitable for profitable commercial grape production. For sites that meet the general minimum climate requirements, its important to match the mesoclimate of your site with appropriate varieties. Your site's mesoclimate is not something you can change.

Soil characteristics are also important, but unlike climate indices, many soil characteristics can be modified before planting to improve the soils and make them more suitable for grape production. The main limitation to doing so is how much money is available up front for making the desired modifications.

Resources

New York Vineyard Site Evaluation System - An interactive, map-based tool for evaluating site suitability developed by Cornell and the Institute for Application of Geospatial Technologies, in Auburn, NY. The Basics of Vineyard Site Evaluation and Selection, housed at this site, provides a comprehensive description of important soil and climate factors to consider when choosing a vineyard site.

NY Macroclimates and Site Suitability - Based on NY climate maps, this document details geographic limitations in frost-free days, heat units (growing degree-days), and winter low temperatures that reduce the suitability of many locations for successful grape production.

Eastern Winegrape Production Guide is a comprehensive reference on all aspects of establishing vineyards and growing grapes in the Eastern US. 300pp, 170+ figures. Order online $75.

Winter Injury to Grapevines and Methods of Protection - 105-page publication viticulture specialists from several land grant universities covers biology and anatomy, climatic conditions, and economics of winter injury, and offers practical help vineyardists for prevention and management. Hard copy only: $15. Order online. View sample .pdf.

New York Growing Regions -- Descriptions of New York's growing regions including the Lake Erie , Finger Lakes, Long Island, Lake Ontario, and the lower Hudson Valley regions.

NRCS Web Soil SurveyThis national site provides digital soil survey maps for the entire US in an interactive, map-based format.

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Content by:

Timothy E. Martinson
Statewide Viticulture Program
Department of Horticultural Sciences, NYS Agricultural Experiment Station
Cornell University