Planting grapevines

26 October, 2006

It is generally accepted that it’s best to avoid planting out grapevines in the cold of winter. Spring is the ideal time and the plants should be underway before the high temperatures of summer make their presence felt.

Establishing a new vineyard, or replacing dead vines, the planting process is part of the annual cycle of the vineyard, so here are some reminders.

It is important to establish a strong root system at the proper depth, as this will anchor the plant, keeping it secure during its lifetime. A strong root system also aids in the development of fine feeder roots to take up water and nutrients. Achieving a strong root system is relatively easy:

Fully dormant rooted plants should have a substantial root system and have made good top growth in the nursery during the previous season.

The plants must be protected, both before and during planting, to avoid drying and overheating. Vines should never be left out in direct sunlight or allowed to dry out.

When hand planting, the plants should be carried in a bucket with water covering the roots. Some growers soak the roots in water for a few hours prior to planting which is fine. Young vines to be machine planted should be covered in wet sacks.

If the soil has recently been sprayed with herbicide, avoid planting out as the roots can take up active residue; this can kill the plants.

Mart Verstappen, Technical Manager at Corbans Viticulture says the young vines should be set at 25 to 50 millimetres below the desired 200 to 250-millimetre depth. The soil should be added while the vine is gently pulled up a little to arrange the roots in a slight downward orientation. The graft union should be 75 to 100 millimetres above the soil line. The soil should be tramped around the roots when the hole is filled.

A newly planted vine should not be easily pulled out by hand

A vine can strangle itself as it grows, so avoid the bunching or twisting of roots and do not push the plant into a small hole as this will turn the roots upwards, resulting in a plant with ‘J’ roots.

Encouraging maximum growth of young vines

Uniform rooting depth is very important for controlling drought stress and properly maturing the crop for consistent wine quality. Encouraging maximum growth can be achieved by providing a balance between the water and oxygen needs of the developing root system and the avoidance of over watering and under watering. If vineyard soils are moist, no immediate irrigation is necessary.

If irrigated, the grower should only apply enough water to wet the root zone and “set” the vines.

Never over excessively irrigate the vines as this cools the root zone down, starves the roots of oxygen and actually prevents new root development.

Regular irrigation should not be started until the vines begin to grow and several new leaves have formed.

Before starting to irrigate, dig near the vines to check soil moisture.

Fertiliser application

Growers should not fertilise until growth has started, and then do so based on the nature of the soil the vines are growing in. In some cases, little or no fertiliser may be required in the first year. To best manage soil nutrient levels, carry out soil and petiole tests.

The most often noted planting problems

Shallow planting is the single biggest single problem in relation to vine failure after planting. Two things happen when a vine is planted too shallow:

The top area of the soil dries out more rapidly than the soil deeper down. This prevents the plant from taking up moisture.

There is a greater plant mass above the ground and exposed to drying winds. This results in moisture loss from the plant.

Plants can dry out through the bark and this leads to minimal growth at best, dead vines at worst

Irrigation of young vines

The young vine’s growth response is triggered by moisture, oxygen and temperature around the root zone. A plant will start to grow when the soil temperature gets to around 13 to 15 degrees Celsius. By frequently applying water, the temperature around the root zone stays cold, preventing the roots from activating. If the “over watering” continues, there is an increase chance for the roots to rot be depleting the amount of oxygen available.

On the other side of the scale, without moisture the plant will dry out. Attention to irrigation is essential.

Young Vines: Did you know…

You should never store young vines where apples are being, or have been stored. Ethylene gas given off by apples in storage can cause rapid deterioration of the grape vines, even when stored in plastic lined cartons.

Bare rooted vines should be planted out as soon as conditions allow, minimising risk of the roots drying out. Where this is not possible, vines should be stored at about 3 to 5 degrees Celsius.

When planting into ground that has recently been pasture, there could be a problem with grass grub ring barking and killing young vines.

Protecting new plants

Milk cartons, plastic sleeves and the triangular or circular vineguards are all seen protecting young vines in the province’s vineyards. Which of these is the grower’s best bet?

Sleeves / milk cartons etc

Advantages: Ease of weed control (reduces competition) and enables easier spraying. Sleeves are relatively cheap, easy to lift up and down for tasks such as cutting the vine back to one shoot.

Good for pest control as rabbits cannot easily reach the vine.

Disadvantages: They act like a sail in windy conditions. A training string to the first wire must be in place to hold the sleeve in place and help minimise the “sail effect” which will eventually weaken the plant’s hold on the ground; if the plant stem undergoes constant movement the plant is probably going to dry out and die. A string to the first wire and/or a bamboo stake can help minimise these problems.

Vineguards

Advantages: The top is attached to the first wire and the base should have soil heaped around it to hold it secure. This system provides better protection than the sleeve. Stringing / training to the first wire is not essential as the plant has to grow straight upwards.

Weed spraying is very easy with virtually no chance of herbicide coming in contact with the plant.

The used vineguard is recyclable and can be sold on to another vineyard.

Disadvantages: Vineguards are slower and fiddlier to do up in the first instance, and then undo for plant inspection. When the vineguard is removed the vine’s stem thickness may be slightly compromised resulting in the first year’s crop bending the stem. The best way to avoid this bending is by ensuring there is no over cropping.

The initial cost of the vineguard system is greater that for sleeves. However, this cost is offset by the health of the vines and the subsequent reuse or on selling of the guards.

The wind can bother vineguards to the point where the odd one will fly away – there will be some maintenance to this system, just as there is to the sleeves.