KSU Viticulture
Trellising, Planting and Training
Hardware for Your Trellis
End Posts: mostly wood posts of 6-9 inches by 8-9 foot long. End posts hold the pulling force generated by vines, winds, and temperature difference. End posts are needed for rows longer than 100 feet. There are many types of end post set-ups, commonly with 60° angled posts or H-type posts. The materials of end posts can be woods treated with preservatives (penta or diesel oil). Pressure treated fence posts are also nice. Black locust and cedar are naturally rot-resistant and therefore are excellent for end posts (and line posts).
Line Posts: posts used in the rows are called line posts. They can be metal or woody. Metal posts of 6-7 foot long are excellent. Wood posts of 4-6 inches by 6-7 foot work fine. You may also need to purchase other supplies depending on the training systems you want to use, for example, supplies for GDC or Lyer. TOP
Earth Anchors: for the 60° angled end posts. Earth anchors are large screws with rings on top and are twisted into ground with a bar. For H-type end posts, the earth anchors are not necessary, but a brace and two end posts are needed for each end.
Wires High-carbon or other high tensile wire of 9-13 gauge, with 12.5 or 12 gauge more common. If you want to plant Muscadine or Concord grapes, 11 or even lower number gauged wire might be necessary.
Staples: Large galvanized staples or brads used to attach the wire to the line posts. Drilling holes in the line posts and passing the wires through the holes are not recommended.
Springs and Wire Tensioners: Those are optional but will buffer the tension and make strengthening wires easier. TOP
Sleeves or Other Wire Joiners: to join two wires together.
Tools: drill, pliers, hammer, shovel, post hole digger, tractor/auger, etc. TOP
Trellising
The best time to set up your trellis is the fall prior to your planting or after planting. Posts can be driven into the ground by a post driver, so check the availability, it is worth the money. Be aware that trellising is not a one-person job.
The posts need to be lined up in the row. You may want to flag out the field and stretch a cord across the row. Usually do the end posts first since it will help line up the posts. The distance between two line posts can be 18 feet for vines spacing at 6-foot or 24 feet at 8-foot, allowing 3 vines between the line posts. Wires can be strung after all posts have been set or after a setting single post, especially when you are not using a post driver. TOP
You should order your vines or propagate your vines the year prior to planting.
Planting time in Kentucky can be tricky since the latest frost occurs in May, after a month's warm temperatures which has boosted rapid growth of grapevines. I would wait until early May to plant my young vines to avoid damaging frosts.
Planting: Check your vines before planting. Choose healthy, disease free vines. Moisten your vines before planting, for example, sit vines in water for about 6 hours (but less then 12 hours). Drill holes, plant the vines and bury them with soil. Trim the roots if you have time although this is not a must. Some books also mention pruning vines to 2-3 buds, which may be not necessary here in Kentucky since the frost would possibly occur. I would prune the new plantings after the latest frost to about 3 buds.
Spraying pre-emergent herbicide after planting (but make sure cover your young vines) will greatly reduce the time for weed control later.
Water the new plantings well ("soak" them!). Choosing an appropriate day when rain comes after planting will save you lots of time. Kentucky usually has lots of rain in spring which would help young vines to survive, but, keep the soil moist at least for the first month. TOP
By definition, a training system refers to the way we position vines in space. It includes Trellis and Training (Training includes Pruning and Positioning).
You should become familiar with your vines by looking at the image to the right. Know these basic terms before pruning: trunk, cordon, arm, cane, spur, fruiting cane.
Training of Young Vines (The first two years):
The principle of young vine training is to develop two straight and strong trunks which would reach the bottom wire. If the first year growth does not grow that high, vines should be pruned back to 2-3 buds again, as you pruned vines last year after planting. It is important to leave 2 trunks in Kentucky in case one of them gets damaged (especially cold damage).
After planting and new shoots getting longer, stake up young vines and tie up the young shoots to the stake, which will help vines to be straight and grow fast vertically. Bamboo sticks of 5 to 6 foot long will be enough to finish this task. When tying the tender shoots, be sure to ease on them--not too tight. High Tubes can also be used.
Sometimes vines have reached the bottom wire after the first year's growth, but after winter, the top part of the shoot may have dried out or been damaged by the winter cold. In this case, prune vines back to 2-3 buds in spring and
develop new "future" trunks in the following growing season. TOP
How to Prune Mature Vines?
Why Pruning? The aims of pruning are : to establish and maintain the vine in a form that facilitates vineyard management; to produce fruit of desired quality; to select nodes which produce fruitful shoots; to regulate the number of shoots and hence cluster number and size; to regulate the vegetative growth of the vine.
Know Your Fruiting Canes. A cane is a mature one-year-old shoot from the previous
growing season. It becomes a cane after periderm formation. This one-year-old shoot is the fruiting cane. All other shoots will NOT bear fruit. TOP
Time to Prune. In Kentucky, hold pruning as late as you can to avoid frost damage to the expanding buds. You can prune your vines in late March or early April, just before the buds start to swell. The theory behind is that pruning posed physical harm to the vine so budbreak will be delayed. But you also have to consider your time and the number of vines to be pruned. Theoretically, pruning can be done anytime during dormant season. After pruning, it is normal for vines to "bleed" (running of sap) for a couple days.
Cane Pruning vs. Spur Pruning. A cane bearer generally has more than 6 countable buds, while a spur is a shorter bearer with 1 to 3 buds. You need to choose cane or spur or mixed pruning according to the fruitfulness of your cultivars. A typical Hybrid has its most fruitful buds at 6th to 12th buds, so you should think about cane pruning in KY. Vinifera has better fruitful buds at the cane base, so you can think of spur pruning. But, one-year-old canes are not so cold hardy, especially at the top part. I would recommend prune them to longer spurs in Kentucky. The pruning type depends on your cultivars and trellis type.
Balanced Pruning. It is the concept of equating buds retained at pruning with vine capacity, i.e., to maintain a balance between vegetative growth and fruit production. The formula is Basic No. of buds retained for the 1st pound of pruning wood + Additional buds for each additional pound of pruning wood.
It is not very popular in commercial vineyards. When apply, you need average first 5 vines' pruning weight and start from their. Please note there is a maximal number of buds retained for a specific cultivar. The known formulae are: American Grapes: Concord (30+10, max. 60), Fredonia (40+10, max. 70), Niagara (25+10, max. 60), others try (20+10, max. 50); French Hybrids: small clustered type, Foch and Leon Millot (20+10, max. 50), medium clustered (10+10, max. 40), large clustered, Seyval blanc, Chancellor(20+10, max. 45); Vinifera Grape (20+20, max. 60). TOP
Pruning for Different Trellis Systems (Jeff Cox, From Vines to Wines, Sunlight into Vines and UK Growing Grapes in Kentucky)
Depends on your training system, you need to develop trunks and/or Cordons.
The First Couple of Years
Then Prune vines according to your training system TOP
Canopy management is temporary solution to canopy problems in vineyards. It won't cure problems in vineyard but serves as "band-aid-viticulture" practice carried put each growing season.
Shoot Thinning It is to remove water shoots, which are shoots developed from buds at the base of spur or old wood. These buds are never fruitful but count for up to 50% of total shoots produced and cause shading. The best time to do this is in spring when shoots are young, about 6 inches long. The criterion is to leave 5 fruiting shoots per foot.
Shoot Trimming It is also called summer pruning, which is to cut off shoot tips during early summer. Shoots are normally trimmed to 10-20 nodes in length, depending on training system and varieties. I do not recommend this practice unless your vines are very vigorous, since trimming encourages more lateral shoots to come which makes you come back and trim them again. Also, late season trimming needs to be avoided.
Leaf Removal To remove leaves from the cluster zone. Leaf removal can open up canopy and increase the exposure of clusters to sunlight and wind. The disease incidence (Botrytis rot) to bunches will be reduced and fruit quality of berries will be improved in return. Also, it makes it easier to harvest, if you do not do machinery harvesting. Usually only a couple of leaves will be removed. It is a very cost effective operation, especially for winemaking. The time to do it is two weeks before veraison. Also, you can remove old, yellow leaves inside the canopy. One thing to be careful of leaf removal is sun burn of clusters. Do not remove too many leaves and be wise when you remove them--be vine specific.
Cluster Thinning The removal of flower clusters. Most cultivars will have 2 clusters per shoot. Some cultivars, however, have 3 clusters/shoot. Cluster thinning is to remove the third cluster, or even the second cluster. Cluster thinning ripens berries early, especially if you grow late mature cultivars and have early frost in fall, it also improves fruit quality. The time to do cluster thinning is before flowering in early spring. TOP