05-Mar-09 08:21 | Eric Stafne

I get this question a lot, “Should I water during the winter when it hasn’t rained (or snowed or sleeted or hailed, etc.)?  This is not easily answered because frankly we don’t know enough to make a definitive recommendation.  My gut feeling is that if one has the capability to water occassionally during very dry periods in the winter, then yes do it.  But don’t over do it.  Perhaps one inch per month would suffice.  Grapevines are fairly drought tolerant; however, drought stressed vines can be severely damaged by cold temperatures whereas unstressed vines may not be.  Unfortunately I have no data to back that up.  It sure would make an interesting experiment.

Overall in terms of irrigation, the period between veraison and harvest is the period when vines should be water stressed to improve fruit quality.  The vine has significant demands for water from budbreak until veraison and don’t forget about after harvest.  The vine has been water stressed prior to harvest, so the soil should be charged with water to full capacity after harvest.