Weeds compete with grapevines for moisture, nutrients, and sunlight. Keep the area directly under the trellis weed-free. Hand hoeing is the most practical weed control method for home gardeners. Cultivation should be shallow to prevent damage to the grapevine roots. Mulches also control weeds. Grass clippings (those not treated with lawn herbicides), shredded leaves, and bark work well. Grapes are very susceptible to injury from 2,4-D, dicamba, and similar broadleaf herbicides and they should not be used on or near grapes.