The main benefit of tall trunks is that they facilitate vine maintenance. Other than this, they tend to have a lower life expectancy than shorter trunks. Tall trunks are therefore unnecessary unless the vineyard is unprofitable. In colder zones, a taller trunk can however prevent the risk of frost. The air closest to the ground is colder than it is at 1 meter up from soil level. (Refer to management of climate extremes)
If the trunk is too low, the grapes will touch the ground, making them more susceptible to diseases as well as adding difficulty for mechanization.
Vine density is a prevailing factor on trunk height; to maintain optimal sun exposure, it is essential to limit the shadow cast. When the sun is not at its highest, the neighboring row can cast a shadow on the bottom of the adjacent row.
The most common ideal trunk height is between 30 and 60 cm depending on the row width. The last factor impacts the amount of leaf surface area exposed to sunshine and therefore the structure of the foliage.