Tuesday, March 06, 2007
Ah, pruning, my favorite gardening activity. I just love taking the saw and hacking things down that have gotten out of hand. In the last post, I talked about planting your grapevines. I found this article on pruning and was one of the most informative of all that I read.
Standing in front of a mass of tangled grape vine and wondering what to do with it can be a scary experience for the novice or even for the more experienced pruner. Keep in mind two essential ideas:
1. Don't be afraid to cut. When you finish, about 90% of last year's growth will be cut.
2. Grape plants are vigorous, and forgiving. Even if you make a mistake, you'll get a chance to fix it next year.
With that said, you can approach your pruning in a spirit of learning and adventure, not panic. Grapes are best pruned in spring (February/March, or even as late as early April) because if pruned too early a hard frost in late winter can damage the canes and buds.
Starting Young Plants Off Right
When you get your new grape plant it probably will not be pruned; instead you will find a vigorous root system and a lot of bare shoots rising out of the top. At planting time in spring you should reduce these numerous shoots to one, and cut it back to three buds (Step 1). After planting, the vine will begin to grow, and push out new green shoots. When these shoots are 8-12" long, choose the best one and support it by tying to a stake at top and bottom. Look for a strongly growing shoot, upright or nearly so, coming directly out of the old stem (not from the underground root system). Remove the other shoots (Step 2).
As the shoot grows throughout its first summer, continue tying it up the stake to keep it straight and prevent breaking in the wind. This shoot will be your permanent trunk, lasting the whole life of the vine, so it pays to keep it as straight and upright as possible.
First Dormant Pruning
Your first-year vine should have reached to or above the first trellis wire (about 30") during the previous season's growth. If it hasn't, cut it back again to 3 buds, and repeat the previous year's treatment. This may seem drastic, but necessary to establish a sound trunk. Most plants are vigorous and will reach the wire easily. If the last year's shoot just reaches the wire or a few inches beyond, cut it at the first bud above the wire and tie the shoot to the stake and the wire (A). If the shoot is longer, tie it to the stake and wire, cut the vine four or five buds beyond the tie, bend the remaining length of shoot down to the wire and tie (B). Very vigorous shoots may go well above the wire and put out strong side laterals. Choose the two laterals that are closest to the wire, tie to the wire, and prune to 3-5 buds. Tie the main stem to the wire and stake, and cut just above the side laterals (C).
During the summer, train the new shoots up to the next wire, and remove any new shoots that sprout from the root area or lower trunk.
To read more of this article, visit this Washington State University site.