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.
Studies have shown that replanting grapevines in soil previously planted to grapes tend not to thrive, or they rapidly decline over time. Although many factors have been determined to cause this lack of vigor, it is important to remember that to reduce the likelihood of these problems, growers may need to pull out the existing vines and allow the land to lie fallow - with a cover crop, say, rye or alfalfa - for one, preferably two, years prior to planting. Otherwise, note that posts and wires can be reused in replanted vineyards, and additional preparation can be completed as described in the Site Preparation page.
Steps to Mitigate Replant Issues
Soil Testing
This is a common theme in grape production; for most questions regarding vine health and vigor, extension agents always ask first, "Have you done any soil testing?" Obtaining a complete soil test will enable you to know what amendments the soil needs. Applying soil amendments before a trellis is installed is far easier than trying to find equipment that will fit between rows AND spread the material effectively.
A local extension educator can provide growers with information on soil testing and recommendations based on test results.
Herbicide History
Some herbicides - such as 2,4 D, glyphosate, etc. - can have residual activities and negatively affect vines in the year subsequent to their applications.
Plant a cover crop for 1 to 2 years prior to planting of vineyard. A cover crop can increase soil organic matter and improve nutrient availability to vines.
Compost
Some studies in plant disease control have demonstrated that composts can have disease-suppression effects in disease-infested soils.
Growers may want to consider compost application during replanting of vineyard sites.
