Every once in a while I get to walk with the Green Man. This happens when I spend time with others (man or woman) who have such a depth of knowledge on whatever trees, plants or garden we’re visiting that I’m convinced they channel the Celtic legend.
I hold that ancient deity with affection. His leafy face often has vines or twigs clinging in his hair, a condition so common to me during the season that my friends hardly blink as I pluck a bit of plant from myself while talking with them. The type of leaves forming his face vary depending on the artist, and sometimes he sprouts horns or flowers.
This time the Green Man arrived, not with antlers or oak leaves, but with a German accent.
Dr. Horst Caspari came to visit from the Western Slope of the Colorado Rockies, traveling to hold a grape pruning seminar at my bosses’ trial vineyard. Well, vineyard is used loosely here, since the little planting can’t be bigger than 100 vines, but Horst didn’t mind – he came to ensure that we would tend these grapes with care.
After explaining the steps to cordon train and spur prune a vine for best fruit production (discussed in my recent Denver Post article), he set about demonstrating both pruning and training of grapes on the Front Range, where rollercoaster temperatures menace the plant with winter kill.
Clipping the canes of last year’s growth so rapidly the pieces flew across the group, Horst became a buzz saw of trimming, keeping up a patter of talk on how to prune for the long life of the vine. With grapes, it seems that hoping for the best but planning for the worst is the goal.
“You need to keep three to four trunks growing from the base of the plant at all times,” he said “and they have to be different ages. That way, if one is killed back you still have two or three. Winter kill can take a trunk easily but it’s rare – very rare – for you to lose all three or four trunks at once.”
Grasping the young, untamed vine, he snipped a few of the wildly growing shoots off, ending up with two older cordons (main arms) and one year-old cane left sprouting from the bottom of the plant. If the plant is on its own root, a shoot from below the soil is fine to keep, but if it’s a grafted plant, nip that shoot off – it won’t be the same type of grape.
Tie the canes to your support pole to give them the idea to grow upright to your wires or trellis by wrapping them loosely with soft plastic ribbon. When the canes reach a wire stretched four to five feet above the ground, lay them over along it, tying them to keep them in place.
On older grapes, the key to continued fruit production is to pick a shoot which grew last year from close to the “head,” or trunk, where the two cordons split from each other. Leave this long – about ten to fourteen buds, then prune all other shoots along the old cordon to two buds.
Lay the long young cane on top of the older cordon and let both grow for the season. Next year, cut off the old arm at the head and tie this new cane to the wire support.
When going out to tame your own grape, don’t be afraid to prune it hard, Horst said. “Grapes are very forgiving. We can train them in a lot of different ways.”