Effectiveness of mulching as an alternative method for winter protection of grapevines

Anirudh Akula
Staff Researcher
Ajay Shah
Food, Agricultural and Biological Engineering

Grapevines are susceptible to freezing damage at temperatures below -4F during the winter season. Preventing winter injury to grapevines is a major challenge in many grape-producing regions, especially in the Eastern and Midwestern U.S. Soil hilling is a conventional practice of winter protection for preventing vine loss in grapevines. However, hilling-up soil every winter to protect graft unions of grapevines has certain risks and potentially negative impacts on the soil-vine environment such as soil erosion, loss of soil nutrients, and potential for physical damage to grapevines caused by hilling and de-hilling equipment which contribute to soil degradation and declining vine health. The objective of this study was to evaluate the adequacy and effectiveness of mulching as an alternative method for winter protection of grapevines. Plant-based mulching for preventing winter injury in grapevines was evaluated over the 2019-2020 seasons. Plant-based mulches of wheat straw, corn stover, and miscanthus of different particle sizes were applied and evaluated at experimental vineyard sites in Ohio in comparison to the conventional method of soil hilling. The temperatures were monitored at 0 and 4 in. above ground level within the applied mulches and soil from November 2019 to May 2020 and compared to the ambient air temperature monitored at 5 ft above ground level. Yield and weed cover was also analyzed for the different mulch and soil treatments. Results showed that the mulch treatments provided adequate winter protection comparable to the conventional soil hilling method by maintaining the temperatures of the grapevines at the graft unions above 32F despite the ambient air temperature dropping below 5F. Mulching had no significant effect on the yield of the grapevines. Mulching significantly reduced weed cover which may potentially result in reduced costs and will be further assessed. The study signifies the potential of mulching as a winter protection method in grapevines and thus will be further developed and evaluated as part of a sustainable grapevine production system.