Protect Grape Vines from Intruding Weeds

California Grower Defeats Botrytis

In 2013, growers across the nation produced a staggering 8.6 million tons of grapes, resulting in an industry worth more than $6.1 billion.1 According to the California Association of Winegrape Growers, the production of wine grapes in the state accounted for approximately half of that value, with $3.16 billion worth of the crop produced last year.2

While cultivating one of California’s – and the nation’s – most important crops, growers must protect their grapes from weed pressures that can reduce yield and affect overall vine vigor. A strong weed management program is integral to a successful harvest. The best practices listed below, along with the help of a certified PCA, can help growers rid their vineyards of costly weeds, allowing them to focus on profits.

  1. Survey vineyards at least twice a year
    Weeds, just like crops, have their own growing seasons, with some annual species dominating during the summer and others during the winter. The University of California, Davis, recommends conducting a survey of the vineyard for weeds at least twice a year: once in late winter and once in late spring or summer.3 In addition to seasonal checking, monitoring vineyards for weeds several times throughout the year can help identify all of the species that threaten the crops.

  2. Consider pre-emergent sprays for prevention
    Pre-emergent sprays enter the seeds of weeds and prevent their normal germination, neutralizing the threat before it breaches the surface of the orchard. Products such as Alion® herbicide from Crop Science, a pre-emergent herbicide, provide a perfect complement to contact herbicides that treat existing problems.

  3. Combat existing weeds
    Once weeds begin to emerge, timing is essential to manage the threat. Controlling weeds becomes harder when they have been left untreated for part of the growing season. Inspect the vineyard after a pre-emergent treatment to find any weeds already established. If there are weeds that have broken the surface, treat immediately with a post-emergent herbicide.

  4. Use the correct method for the soil
    Weeds and the products used to treat them behave differently in various soil types. Always read and follow label instructions and use rates relevant to the specific vineyard to help get the most out of the treatments.

  5. Consider planting a cover crop
    According to the University of California, Davis, planting cover crops between rows of vines can reduce weed pressures by minimizing the areas in which the weeds can grow. Weeds have a hard time growing in areas where they have to compete for nutrients with recommended cover crops, such as wheat or barley.3


Weed management is an essential part of ensuring the highest yield and healthiest vines from year to year. Follow the above best practices for a comprehensive weed management program for the entire season.

Learn more about weed management and how a long-lasting, pre-emergent solution like Alion can help reduce yield loss and improve vine health.

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