If you’ve ever driven through wine regions in winter you have an idea of how bare and pretty ugly properly pruned grapevines look. During the ‘dormant season’ they aren’t the gorgeous leafy vines we adore because they’ve been pruned.
The pruning can appear to be quite extreme but it is needed to support healthy vigorous vine growth in spring and summer, and ensures tasty, well-formed grape clusters during the grape picking season.
There is a secret and an art to pruning grape vines.
The SECRET – Grapevines produce grapes on wood growth that is one year old. Older wood growth produces only leaves or shoots, but no grapes! It’s the new shoots that turn brown by the end of the growing season and produce buds on which some will develop flowers that develop into grapes.
The ART – Our goal when we prune is to maximize the amount of one year old wood growth on each vine but discourage the vine to produce so many grape clusters that it lacks the energy and nutrients to fully ripen them. If we didn’t prune each year, a grapevine would grow into a dense bush of mostly older ‘wood’ with comparatively little wood that fruits each year. The dense bushy growth can lead to poor air circulation which encourages fungal diseases. We expect to remove more than 75% of a previous year’s growth each winter pruning season.
We also prune because we want to grow vines in a structure that suits the trellis we’ve built and makes it efficient to grape picking.
For newly established vines we follow 3 pruning steps so our vines develop in the way we want:
Year 1 – establish the trunk
Year 2 – establish the lateral branches
Year 3+ – establish the fruiting spurs or shoots
Our pruning rules also include:
- Sterilizing our equipment by dipping the cutting blades in a solution of isopropyl alcohol. This helps reduces the spread of unwanted diseases and mould spoors
- Removing any diseased wood
- Making cuts that aren’t flush to a trunk or branch at least 2 centimetres above a bud and at roughly 45 degrees. This allows water to roll off rather than catch in the pock mark that usually develops where a branch has been cut off
- Tying shoots loosely to the trellis. We do not want the tape we use to constrict growth and it will eventually decompose once the branch is stiff enough to support its own weight.