Grapes fruit on new season wood. Prune your grapes every year to avoid a tangle of shoots and to grow better fruits. Grapevines have a tonne of vigour and left to their own devices take over the garden, next stop the world.
The good news is grapes can handle a hard prune, so if your grape is a jumble of shoots and has left its tidy trellis for dust – get stuck into it. You really don’t need to worry about pruning too much off a grape!
Make a frame
Grapes are wonderfully malleable, easily trained over a variety of structures. No matter which way you frame it, be sure of these 3 things:
- Strength. There’s alot of weight in all those bunches of grapes not to mention the vine itself. Put some effort into something solid and lasting, cos a grape has legs.
- Bird protection. Can you easily throw a birdnet over?
- Airflow and light. Air keeps your grape healthy, and light keeps it productive. Be sure of both with generous 40 – 50cm gaps between each row of your structure, and between the ground and the first wire. If you are training your grape above a covered deck be sure of a generous gap between the roof and the grape.
And here’s my best tip – put your structure up before you plant your grape… you know who you are!
The leader is the main stem that goes from the ground to the top of your structure. From the leader springs the cordons – the side arms that carry the fruit.
You only want one leader. Choose the strongest and best placed shoot for this job and remove any competing shoots. Don’t be afraid to prune an out of control vine back hard to create this clear structure – grapes can take it.
- In the same way you only want one leader, you only want one cordon per wire.
- Go along each cordon and remove all the dead wood.
- Remove thin, spindly shoots and long, fat thumb size shoots, keeping those that are pencil size diameter – these are the most productive.
- Where there is a cluster of shoots, create about a 10cm gap between each shoot by removing the weak ones and keeping the best ones.
- Cut back your chosen shoots to 2 – 5 good buds, this turns the shoot into a spur. Where the shoot gets spindly and weak that’s your deciding moment – cut it there. You’re in the business of keeping healthy, pencil size wood only.
- Grape wood dries back after cutting so leave about a centimetre of wood above the bud to allow for this.
- Trim the ends of the cordon to fit your frame.
Burn your prunings. Grapes flaky bark provides excellent bug habitat.
When a cordon looses it’s mojo, cut it off and replace it with a new shoot. Choose a shoot that comes off the leader, about 10cm below the wire. Below the wire is best, so that when you bend it onto the wire it comes at a good angle.
Restoring old vines
If you’ve inherited a grape that’s super tangled and gotten seriously out of control – choose the strongest shoot coming from the base to be your replacement leader and cut the rest down. Grapes can take it.
Sometimes it’s simpler to begin again.