Pruning Grape Vines in a Cool Climate

Before tying down your vines!!!

Be sure you have tightened your fruiting wires and checked the stability of your posts. Once you have tied down your vines, it is difficult to do this job without damaging the new buds on your pruned vines. DON"T FORGET

Pruning Grapevines in a Cool Climate

By June , the vines will have shut down and lost all their leaves. There should be no green wood remaining.

The following guidelines can be used for pruning your vines to be optimally productive, however remember that mature vineyards rarely produce the perfect vine. Building good vine shape takes several years of judicious pruning.

To prune successfully, you need to think of vine growth not only for the current season but of the consequence of current actions on vine growth in the years ahead.

Some basic principles can be offered here.

Vine Anatomy

Spur-pruned Vines

The vine consists of a butt emerging from the ground, a trunk, a crown where arms or cordons branch in other directions and spurs which contain fruitful buds for the next season's fruit.

 

Fig.1. Anatomy of a spur-pruned vine

 

 

 

 

 

A well set up spur-pruned vine ( single wire Vertical Shoot Positioning) will have evenly spaced, upward pointing spurs along the cordon. I generally restrict each cordon to 6 spurs so that the vine is not over-cropped. Each spur will potentially have two buds, each of which will produce 2 bunches of fruit. The potential of the vine pruned this way is to produce 48 bunches of fruit ( about 3-4 kg)depending on the variety of grape and the location of the site.

All unnecessary old wood will be removed and the crown will be 10-15 cm down from the wire.

Fig 2. Anatomy of a spur

Fig.3. Cutting the spur

 

 

 

 

Steps in pruning a vine to spurs:

Look at each vine from the centre to see that it has a reasonable distribution of spur positions. Spurs desirably should be about a fist width apart along the cordon and pointing upward. Do not encourage downward pointing spurs. If the spurs are more than 3 seasons old, the fruitful buds may be getting too far away from the cordon. It may be better to lay down a new cane comprising 6-8 buds.

Prune each spur position to the lowest possible bud.

The crown should be a secateur length down from the wire.

Avoid spurs in the crown of the vine.

Cut spurs to 2 buds in addition to the base buds.

De sucker the butt and trunk of the vine.
All cuts should be clean so as not to leave buds in unwanted positions.

Common problems you may experience:

When selecting the spur look for the lower bud on last year's spur (as in Fig.3). This prevents spur positions from becoming extended and becoming tall ( Fig.7)

Fig.7. Spur pruning-long spurs

 

Fig.8. Spur pruning- canes used to establish cordons too long

Shoots from a base bud or water shoots ( shoots that did not bear fruit last year) at the base of a spur provide a good opportunity to maintain spurs near the cordon.

In laying down a cane to establish a new cordon or extend an existing one, it is best to err on the side of conservatism. A cane of 6-9 buds, depending on the vigour, will ensure that all buds burst and provide the opportunity to select good evenly spaced spur positions. If long canes are used in order to increase the bud numbers, it will often result in patchy shoot distribution. This poor shoot distribution will result in big gaps between spur positions and reduced bud numbers for the life of the cordon. (5-10 years). I do not recommend double wrapping of canes to create more buds as this creates a harbour for disease and often leads to overcrowding of shoots in the canopy.

The crown of a vine should ideally be 10-15 cm down from the wire. High crowns, make the vine very rigid, and this commonly results in splitting of the vine trunk when trying to wrap the canes down on the wire. Low crowns lead to a waste of space on your wire.

The other very common fault in spur-pruned vines is the failure to clean out the crown. The crown of the vine is commonly where most vine pests and diseases start their cycle so it is best to keep the crown fairly open to allow air movement. In some years you will also get many water shoots coming from the crown area which will need to be thinned out to avoid overcrowding.

Cane Pruned Vines

Fig .4. Anatomy of a cane

Fig. 5. Anatomy of a Cane pruned vine

A well cane- pruned vine has two well-ripened canes of 12-15 buds and one replacement spur for each cane. The canes should originate from close to the crown. They should be cleaned of bunch stems and lateral shoots from last season.

The vine is trained to a head under the fruiting wire and canes containing fruitful buds from last season's growth are trained along the wire.

The head of the vine should be about 10cm below the fruiting wire.

 

Steps in pruning a cane-pruned vine:

Look for suitable replacement spurs, preferably below the cordon and following along the row.

Replacement spurs are left to replace canes for the next season's canes.

Look for good canes ( strong canes with trimmed laterals good node length and colour not too far out from the row, free of splits or cracks).

Prune off old canes.

Remove old canes from the wire and pull out.

Cut replacement spurs

Clean up canes and train to 6-8 buds each, cutting through the end node to exclude the bud.

Cut off all unnecessary shoots and old wood.

Wrap canes by taking the cane to the wire and wrapping over at least twice, then tying down with wire on the final internode.

Never tie off on live tissue.

Check and de sucker the trunk.

Common problems to be avoided:

If you cannot find suitable replacement spurs for next season's canes, reduce the number of buds on your cordon to 6 and this will force the vine to throw out more suckers from the head which can be used for next year's replacement.

A low crown vine can also be a problem because it often has too much unused wire and too many buds used up in getting to the wire, resulting in crowding of the crown.

crown too low Fig.10. Spur pruning- crown too low

With a bit of practice you will soon learn how to make the best decisions so that you promote a balance of healthy canes yielding quality fruit.

Remember:

The vine has a finite potential to yield optimum fruit quality.

Too many buds will result in overcrowding and fruit of poorer quality.

Too few buds will force the vine to produce suckers from the head and overcrowd the crown of the vine, necessitating further pruning in November when the vine is growing rapidly.

Pruning wood

A well ripened cane will be pencil thickness with have even colour and buds spaced about fist width along it.

Scott Henry Pruning:

When vines are over vigorous through spacing that is too wide or growing in a high vigour soil, it is necessary to force the vine to produce more fruit in order to balance the vigour. Overly vigorous vines will produce high, dense canopies that restrict the flow of air and lead to disease.

The Scott Henry system has two fruiting wires about 30 cm apart and a cane is trained in each direction to both top and bottom fruiting wires. The bottom canes are not wrapped over, allowing you to turn down the shoots when they harden a little in late November.

When the growing canes are developing tendrils and becoming firmer at the base, they will be turned down with an extra canopy wire that is placed initially just below the top fruiting wire. About lateNovember the bottom shoots will start to harden and grow tendrils to support themselves. At this time they can be turned down by lowering the canopy wire gently to a hook about 30cm from the ground. Potentially now the vine will carry 4x6x2 = 48 bunches of fruit.

Scott_Henry pruning

 

 

 

 

 

 

 

 

 

Fig 11. Scott_Henry pruning

The video clip below demonstrates how to prune a Scott Henry trellis vine to produce optimum fruit.

 

An Effective Trellis

Cane_pruned trellis

 

 

 

 

 

 

 

 

 

 

 

Fig 12. Vertical shoot-positioned layout

 

The most effective trellis for a vertical shoot positioned vineyard to gain maximum sunlight is shown in Fig.12.

The vine is pruned to twelve buds on 2 canes. In addition, 2 spurs of 2 buds are left below the wire for replacement canes in the next season.

The growth of the vine during the season will approximate the pattern in Fig.13 below.

Tools for pruning

secateurs

A sharp pair of roll-handle secateurs is the safest tool to use for cutting vines , especially if you have a few to do.

This tool will cost about $50 and should last you a lifetime if properly looked after. The rolled handle will lessen the risk of tendon strain.

The picture shows the correct grip for sharpening the blade with a small stone.

Hold the tool in your left hand with the curbed edge of the blade closest to your body. Hone the edge use a small whetstone held at the correct angle across the blade.

Remove any bur from the sharpening by using the stone flat on the reverse side of the blade.

Sharpen your tool after every few hours and it will keep cutting cleanly.

 

 

 

 

 

 

Roll-handled secateurs and whetstone

 

 

 

 

 

tools

 

 

Tool bag for a viticultural worker.

 

 

 

 

 

 

ties Ties for securing the cane to the fruiting wire can be light gauge wire or plastic. It is important to remember to tie off the vine after the last fruiting bud as the pressure of the tie will restrict the sap flow past the tie. Cut through the bud that is to be past the tie.

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This page was last updated on 07/11/2009