In the vineyard

Trellis and training: the shape a vine is held in

A trellis is not scaffolding. It decides how much light reaches the fruit, how fast the canopy dries after rain, whether a machine can work the row — and in Ontario, whether the vine can be laid down in November.

Vertical shoot positioning, and why it dominates

The standard system in Ontario, as in most cool-climate regions, is vertical shoot positioning. The fruiting wire sits roughly a metre off the ground, shoots are trained upward between pairs of movable catch wires, and the canopy forms a narrow vertical wall with the fruit in a defined zone near the bottom.

Its advantages are exactly what a cool, humid climate needs. The fruit zone is easy to reach for leaf removal and for picking. Air moves through a narrow canopy, so clusters dry quickly after rain. Spray reaches the fruit rather than being absorbed by a mass of foliage. And the wall geometry exposes leaves to light efficiently, which matters where the season is short and every degree-day counts. The disease page covers why drying time is the central variable here.

Divided canopies, for vigour

VSP has one real weakness: it assumes moderate vigour. On deep, fertile, well-watered soil a vine will grow more than a single vertical wall can carry, and the canopy becomes dense, shaded and slow to dry — the conditions that cost growers crop to rot.

The answer is to divide the canopy. Systems such as the Scott Henry, which splits shoots upward and downward from a single trunk, or the lyre and Geneva Double Curtain, which split them horizontally into two curtains, give a vigorous vine twice the space to fill without doubling the density of any one part of it. They cost more to build and more to manage, and they are used here on the sites that need them rather than as a default.

The Ontario constraint nobody else has

Every training decision in this province is made under a condition most regions never consider: the vine has to survive winter, and the measures that achieve that impose their own geometry.

Hilling up requires the graft union to be low enough to bury under ploughed soil and the vine row to be clear enough for a plough to work along it. Full burial, standard practice in Prince Edward County, goes further — the canes have to be flexible enough to lay down and the trunk architecture has to bend without breaking, which effectively rules out a rigid high cordon and pushes growers toward cane pruning on low, supple trunks. The winter protection page covers both practices; the pruning page covers the wood choices that follow.

Multiple trunks are the other structural adaptation. Training two or three trunks per vine rather than one costs some early yield and buys insurance: lose a trunk to winter injury and the vine carries on, where a single-trunk vine has to be rebuilt from the ground.

Row orientation and spacing

Which way the rows run decides how the canopy is lit. North-south rows give both sides of the canopy a share of direct sun over the day, which is the usual choice; east-west rows light one side heavily and shade the other, which can be deliberate on a very hot site and is rarely what an Ontario grower wants.

Orientation is also a wind and drainage decision. Rows aligned with the prevailing wind dry faster; rows aligned across a slope slow water movement and erosion but complicate machinery. And on sites where cold air drains downhill on still nights, rows that run across the slope can pool that air rather than letting it flow away — a small decision at planting with permanent consequences. Spacing follows from vigour and equipment: closer spacing raises vine numbers and competition per vine, and has to leave room for whatever tractor will work the row for the next thirty years.

A thirty-year decision

What makes trellis choice consequential is that it is close to irreversible. Posts, wires, anchors and vine spacing are installed before the first crop and stay for the life of the block, and converting an established vineyard from one system to another means rebuilding the trellis and retraining every vine — years of reduced yield for an uncertain gain.

So a trellis decision is really a forecast: about the vigour the site will show once the vines are mature, about the variety that will be planted there in twenty years, and about the winters to come. The vine year page follows the season the trellis has to serve, and the varieties page covers what tends to be planted where.