Should I prune my grape so it only has one main vine?

I'm new to grapes, and bought several varieties this spring, half table and half wine. I usually take the advice of just letting them grow the first year and get established before I bring the pruning shears out, so maybe I don't need to do this now or maybe I should? Or maybe I don't need to stop this?

I have what I feel is the "main" vine on the left there, and a "secondary" on the right. I think that I'm just supposed to have one at this stage of the game, yes?

I grow Concord grapes. Have never pruned them other than whacking off the bits that get too long. Two vines makes more grapes than one family can eat or make jam from.

Your varieties may require pruning, or your climate. All I can say is Concord grapes do not.

I hope some grape expert chimes in here.

I would just let it grow and establish itself for the first year, and then go to town on it next year.

In general, grapes tend to produce more reliably when pruned heavily.

However, newly planted grapes don't flower, so they won't produce fruit this year. I would allow both shoots to grow, then prune one off next spring. The remaining shoot will inherit the vigor produced by two shoots this summer.

When I grew seedless table grapes in the desert, there was some advice I read in a local gardening guide that talked about a "rule of twenty" for established vines. Evidently the two most popular varieties were Thompson and Flame, and they had different flower development pathways (and I no longer remember which was which, but the important thing was that there were two).

The idea was that when you pruned the vine, you left twenty spurs of the most recent season's growth, each with 2-4 buds. One type of vine responded best to having two main leaders, each with ten spurs. The other type did better with ten leaders and two spurs per branch. Apparently you could split the difference and do a 4x5 pattern and that was a pretty safe bet.

I followed this rule with my two vines and got bumper crops for several years. Now I've got a purple Concord-type vine, as well as red and green, in a quite different climate. I'm pruning them all according to a 4x5 plan and this is going well.

For a new vine, getting a main stem or two growing in the direction(s) you want is a good place to start. The third or fourth season will be when you start applying a spur distribution pattern. Over time, you can take out older main stems and train new growth to replace them.

I think you should have several vines, healthier and more natural for the plant probably. If space allows it I personally wouldn’t prune at all because I love rambling wild things. Fukuoka’s books suggest that pruning may screw up a plants ability to grow normally without crossing branches or making them too long and leggy.