By Michela Centinari
Over the past year, many questions concerning site selection have risen from prospective growers interested in pursuing a vineyard enterprise. Whether you already bought or inherited land and are wondering how well it is suited to grow wine grapes, or you are considering purchasing land, the following resources can help you identify site characteristics that will contribute to a successful vineyard. Additionally, these tools can help identify factors that may signify a risky investment for wine grapes.
Vineyards are long term financial investments. Site selection is the first and one of the most important decisions wine grape growers will have to make. It is key in determining what varieties can be planted. The choice of the site will greatly impact vineyard enterprise profitability and, thus, its economic success or failure.
Poor site selection and preparation lead to:
- lower yields,
- more vine injury,
- routine harvest periods of unripe grapes, and
- higher management costs .
Therefore, a prospective grower should not underestimate the value of the time and effort put into finding the right site for a vineyard location.
Dr. Robert Pool, former grape specialist at Cornell University provided the following concise overview of vineyard site selection “The most fundamental and irreversible 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 identifying a site where the vine can grow and mature is crucial to the very survival of the future vineyard.”
This statement underlines the additional challenges, mostly related to macro and meso-climate limitations, which need to be considered when choosing a site in cool and cold climate regions. In addition to a well-drained soil of moderate fertility, and adequate depth, winter temperatures, spring and fall frosts, length of the growing-seasons and heat-unit accumulation needs to be carefully evaluated.
For specific information about the principal physical and biological features evaluated in the site selection process see:
- Two-years Pre-plant: Site Selection_Cornell Cooperative Extension, Finger Lakes Grape Program
- Vineyard Site Selection_Virginia Tech Cooperative Extension
- Basics of Vineyard Site Evaluation and Selection a part of the New York Vineyard Site Evaluation System
Digital soil maps are available online through the NRCS Web Survey
Matching wine grape cultivars to your site
A team of scientists at Virginia Tech University led by Peter Sforza (Director of the Center for Geospatial Information Technology, Virginia Tech) are developing a GIS-based model Eastern US Viticulture Suitability web portal which incorporates climatic, topographic, and edaphic parameters to improve “site-cultivar” suitability knowledge. This project is funded by the USDA-SCRI grant (“Improved grape and wine quality in a challenging environment: An eastern US model for sustainability and economic vitality”), Virginia Wine Board, Virginia Vineyards Association. Dr. Tony Wolf, Professor of Viticulture at Virginia Tech, is the project director of the USDA-SCRI grant.
This on-line resource allows you, while sitting at your computer, to conduct a very precise, satellite-based search of a specific plot of land. You can draw a polygon and delimitate the area of interest (area must be between 0.1 and 200 acres). Within minutes, a vineyard evaluation report will be created complete with an overview of the site conditions: soil, climate and topography information based on an average of 30 years of data.
This web-tool is still in its developmental stage. Over the next 4 months Peter Sforza and his team will continue a release schedule with updates and new features for the major goals including:
- Develop a Site Score Card using soil/geology, climate, topography, and biological factors. A Multi-Criteria Decision Analysis (MCDA) is in the process of being established which will have the ability to establish statistically valid weightings for the different criteria (i.e. define attribute/criteria in a hierarchy). This information will be summarized in a Site Score Card. High performance computing capabilities at Virginia Tech are being used to process and analyze data for over 125 GIS layers across the eastern US (19 states).
- Match a cultivar or multiple cultivars to a site (variety x site). The initial version of this is based on average growing season temperatures, a model developed by Dr. Tony Wolf.
The main challenges related to this project, as Peter Sforza highlighted, are:
- synthesizing information across multiple states, where the bases for state-based guidelines are not uniform (i.e., frost free period based on 29°F vs. 32°F); growing season definition (i.e., April to October vs. March to November). Dr. Wolf and Sforza are working to link the East Coast vineyard site suitability tool to the state-specific recommendations.
- limitations of ‘Average Growing Season Temperatures’ to make data driven decisions. This parameter doesn’t take into consideration temperature variability across the growing season and at different stages of grapevine development.
Some of the new features expected are:
- A pdf vineyard evaluation report emailed to the user
- New web interface and portal
- New report sections/pages (topography, geology information about the context of the surrounding area)
- Tutorial video
- Grapevine maturity groupings in relation to climate conditions
- Site score card
This is a great tool, and it should be considered a convenient prelude but not a substitute to vineyard site visits and consulting with Universities’ Cooperative Extension educators that have expertise in viticulture, a skilled vineyard consultant and soil specialists.
1. Martinson, T. 2-Years Pre-plant Site Selection. Cornell Cooperative Extension. Finger Lakes Grape Program.