Plastic mulches are also beneficial. Mulching is good on sandy or coarse soils but avoid heavy mulching on poorly drained soils. In the fall before planting, destroy weeds by deep plowing, systemic herbicides or mowing. Put plastic mulch down before planting. After planting, apply a preemergent herbicide to control annual weeds if plastic is not used.
Spot treat or remove weeds around plants by hand.
If vines are not touching the first wire in the second year, treat them as newly-planted vines and use herbicides approved for newly transplanted grapes. As vines become established and the trunk becomes mature, certain herbicides can be used for persistent weeds. Sinbar, Simazine and Karmex may damage or kill young or mature vines. Reduce the rate or use other less toxic herbicides. Follow local recommendation and those listed on the label.