I bought a concord grape stalk this spring from the garden centre. Just a stick with buds and roots, no wood. I stuck it in a container (we don't own the lawn where we live, sadly) and so far it's grown three large shoots about 3 feet long each with big fat leaves. After checking with the Internet, I remain unsure whether I should have tried to train it on a trellis already (it's tied to three bamboo poles at the moment) or whether I should let it be until next year and prune it for a trellis then. if I should have trained it (and clipped some of the shoots presumably) do I have to wait for winter pruning, or can I do it now? Obviously fruit is not coming this year, but I want to make sure that the wood grows nice and sturdy. Thx, UBC board!
In this climate, grapes can be pruned any time of year, except, perhaps, during spring when their sap is very runny. I prune my grapes all summer to eliminate excess and unnecessary growth. And after harvesting the grapes in the late summer or fall, I remove the whole shoot that bore the fruit unless I want to save it for next year. I would remove two of the three shoots that your plant has so that the remaining shoot will grow faster and produce more leaves. The new shoots have to mature sufficiently to survive the winter, and more growth will help, as long as the plant is getting plenty of sunshine and the growth is not too spindly.
I, too, prune my Grape plants not only early in spring before the sap starts running, but also during summer, to restrict excessive shoot and fruit production. Here is what, I believe, is a good general information on the pruning method: http://extension.missouri.edu/publications/DisplayPub.aspx?P=G6090 You can adapt it to your own growing conditions.
