trimming, the vineyard operation of removing unwanted shoot growth which can cause shading and hinder spraying. Although it is usually done with a trimming machine mounted on a tractor, it may also be carried out with a hand-held machete or similar device. The operation normally removes the shoot tip and a few leaves below it, or about 30 cm/12 in of growth, thus leaving the shoots trimmed to about 15–25 nodes, or 70–150 cm/31–58 in. Trimming is essential in vineyards with high vine density to stop shoots from adjacent rows from growing together. Regrowth may be such as to demand up to six trimmings a year, particularly in vineyards well supplied with water (by rainfall or irrigation) and nitrogen. If shoots are trimmed too short then there may be insufficient leaf area to ripen the crop properly (see leaf to fruit ratio). Resulting wines will be lower in alcohol and of lighter body and colour. Sometimes vineyards are trimmed so neatly on the top and sides that vine rows can look like a recently trimmed hedge, hence the alternative term hedging.
