As the temperatures warm up and everything seems to be in bloom, many folks are contemplating planting grapes. It is a good time for that, but caution is advised. The biggest danger this time of year is a late frost. We have a short growing season even at lower elevations. It’s best to plant grapes after the danger of frost is past. Grapes will survive a frost. Each bud has 3 baby buds inside. But by the time they come out to replace a frozen leaf, there is little chance of bringing in a ripe harvest. An additional perk to waiting is that the buds eventually show themselves and you will be able to select very viable plants.
Historically, wine grapes were grown in Europe. But grapes are also native to North America. This leads to feuds and a sorted history. When American grapes, were introduced in Europe, they brought with them a disease called Phylloxera which is caused by an aphid. The blight from this insect quickly spread throughout Europe devastating crops. Eventually grape growers realized that grapes grown on American rootstock were immune to the disease. After grafting the true vinifera grapes onto new rootstock, the European wine industry revived but not without grudges. French/American hybrid grapes are often banned in Europe.
Another contrast between American grapes and European vinifera is in the heritage of the French/American Hybrid grapes, many of which are grown in Northeast Washington live in forests. True vinifera from Europe tends to be “well behaved” meaning that they grow new canes every year from set locations on the cordon, (the arms of a grape plant trained along a horizontal wire). Pruning consists mostly of cutting back last year’s canes to a single bud and letting a new cane grow there.
Hybrid grapes, however, love to climb to the top of trees as they would have done in their New England native habitat. This makes pruning more challenging since they resist being limited to sprouting from last year’s canes. This leads to a discussion of cane vs spur pruning which is beyond the scope of this article.
Determining how you want to trellis your grapes is an important factor. Generally speaking, grapes like air and light. Having a wall to the north of the vine is usually helpful. Not only is soil an important factor, exposure to sunlight is also key to planning a vineyard. The higher a plants canes are off the ground, the more impervious it is to frost. Selecting the strongest shoots to attach to a vertical stake or rebar when they are first planted is a good way to insure that they will attain a good height. Sometimes this takes a couple of years. In the meantime, trimming off potential clusters of grapes promotes growth.
Another perpetual source of grape confusion is seedless, vs wine, vs juice. This aggravates me not only because historically I have grown wine grapes, but also because wine grapes have been selectively bred over thousands of years to produce great tasting juice. If you are aiming to produce juice, consider wine grapes. They produce abundantly and the juice can be pressed out easily.
Another pet peeve is steam extraction. The extra-ordinary amounts of sugar in grapes – typically twice the amount in pears or apples – is significantly degraded by steam extraction. Granted, the juice can be too sweet and steam extraction dilutes that.
Sometimes I compare growing grapes to getting married. They need attention and care. Maybe it’s like the police “protect and serve”. This year is stacking up to be very dry. I wasn’t aware of just how dry it was last year until I got a soil probe. It is easy to push it into the ground and see what color the soil is and how damp it is. Already the soil here on a bench by the Columbia is very dry. Watering grapes is another skill that sometimes becomes lost in translation. Grape expert Wes Hagan says “Vines that are “trained” to learn that their water only comes from one place (a drip emitter or a hose) will develop a root ball near the surface of the soil and will not develop a deep and wide root system. Deep, infrequent applications of water are, in my estimation, best for the vine.
I use a sprinkler system that spins water out near the surface of the ground. In my experience growing grapes, their roots tend to spread out. To get water to them, you need to spread the water out too. Overhead sprinkling is a no-no. Water on grape vines leads to mold and powdery mildew. Those two culprits will shrivel the grape clusters and rot the leaves. Conversely, too much water in the ground will not allow the roots to breath and will kill the vine.
So go ahead and grow yourself some grapes. But plan ahead and be prepared. It’s a long-term relationship.