Maintaining Young Vines

Once the vine has been planted, (see 3.3 Planting Grapevines) care must be taken to ensure a healthy plant. The first shoots from a young plant are fragile. Each plant will produce a number of shoots from the scion. Early careful removal of all except the single strongest most upright shoot will help ensure a good start for the young plant.

Young plants should be protected with milk cartons or plastic tubes, be kept weed free around the plant base and never suffer water stress. Water stress should not be considered for at least the first two years and sometime three depending on the strength of growth. Irrigation sets should be frequent and of short duration ensuring that there is always adequate moisture to a point just below the furthest extent of the rootzone. It is not necessary to irrigate well past the rootzone as this wastes water and leaches nutrients out of the rootzone.

As the young plant grows tying should be done every 10 – 15cm of growth to help ensure a straight and non damaged trunk. The vine is tied to a stake that is affixed to the cordon wire. If growth is slow, removal of the axial shoots at the base of each leaf will encourage more growth.

Continual monitoring for pests, disease and nutrient deficiencies will help the vine achieve its maximum growth potential. Young plants should be included in a standard mildew prevention program similar to adult plants. Cutworms can be a significant problem in young plantings and should be monitored carefully in the first 3 years.

See section 5.3 Pests and Diseases.

If the plant is grafted an inspection of each plant should be done later in the season in both the first and second year to remove any scion roots having grown past the graft.

The second year is much like the first year in many respects. The vine is kept free of weeds around the base, all trunk suckers continually removed and treated as an adult plant for mildew and disease. If the cane has achieved at least pencil thickness above the cordon wire, the vine can be tied to the cordon wire and 4 buds left below the cordon. In cases of exceptional growth where the cane is at least pencil thickness 60 cm above the cordon, the vine can be tied down on the cordon.

The amount of fertilizer used in the second year is dependent on the growth in year one. The type of the fertilizer should be based on the soil analysis. If the soil was balanced with amendments prior to planting, minimal additions will need to be added. See 4.3 Nutrition for further reading. 

Vine Rejuvenation

Severe winter temperatures (below -20°C) or very cool temperatures during the shoulder season (below -12°C) can cause substantial damage to the fruiting buds of many varieties. If bud damage is suspected, the severity of bud damage should be assessed by bud dissection. Pruning methods should be changed based upon the number of dead buds and the age of the vine. For mature vines more buds should be left in order to compensate for dead buds. On spur pruned vines it is important to leave renewal buds below the cordon as it may be necessary to replace the cordon in the following year if too many spur positions are lost. 

If the fruiting wood is severely damaged the trunk and the roots can still be functioning. A dead fruiting structure can trigger very vigorous re-growth from the base of the vine and from the trunk area. 

The objective is to absorb the strength of the root system and create a new trunk and fruiting wood capable of surviving through next winter. Excessive vigor produces canes that are particularly susceptible to cold winter injury. Begin by removing the dead plant structure, although the dead trunk or what remains of it could be used to train the new shoots. Allow most or all of the new shoots to grow and tie them as with first year growth, ensuring a straight trunk for the future. Do not fertilize the plant as the growth will be very lush without any help. Disease control for powdery mildew is very important as the new growth is particularly susceptible. Water control may also be an option in order to slow the growth and ripen the wood for winter..