What happens if I top or hedge grape vines before bloom?

Topping or hedging before bloom will result in significant lateral shoot development, often within the fruiting zone. This additional leaf area can lead to canopy crowding, shading, and high disease pressure in the fruiting zone. The need to top or hedge as early as bloom is a sign that the growth potential is higher than optimal. Growers should consider reducing nitrogen and/or providing some competition for the vines by using cover crops in the vine middles.