What's in your Watershed: California Wild Grape

By Dan Kirk

I don’t know much about the process of wine making, but based on observation, it seems as though it’s the season to harvest grapes and begin the process. My observations include: seeing lots of grapes at the farmers market, walking under a grapevine at an entryway and picking grapes and eating them, and having a conversation with a friend who recently harvested grapes to make wine. Okay the last one isn’t really an observation, but our conversation did inspire me to think about grapes native to California.

As it turns out, Vitis californica, or California wild grape, is a native species of grape that grows throughout central and northern California and southern Oregon, and occasionally in southern California. It is a deciduous vine which can grow to over 30 feet, climbing over other plants and covering the ground with twisted, woody ropes of vine covered in leaves (when it’s the right season). In the fall the leaves turn many shades of orange and yellow, and bunches of small and often sour but edible purple grapes hang from the vines. The California wild grape grows along streams and rivers and thrives in damp areas; however, like most other native California plants it can withstand periods of dry conditions. The grapes provide an important food source for a variety of wild animals, especially birds. Bees love the flowers, and it is one of the best plants for butterflies in fall.

If you’re wondering whether the vine could work in your garden or backyard; it could. Pros: Little or no incremental irrigation once the roots have been established. The roots are strong and go deep into the soil and because of this, the plant is sometimes used for riparian restoration. It will gladly take more water, but then it may get huge! Cons: A huge California grape vine means a continuous pruning, possibly, and some leaf maintenance when the leaves fall.

So, back to wine. You wouldn’t want to make wine out of these grapes (though I bet someone out there has tried and succeeded!), but the interesting thing is that Vitis californica has a very sturdy rootstock, and is of great importance to wine industries around the world. This species was used to save the European wine industry between 1870 and 1900 when most wine grapes (Vitis vinifera) were killed by leaf- and root-attacking grape phylloxera aphids. Since that time, nearly all commercial wine grapes grown anywhere in the world have been grafted onto rootstocks of resistant California wild grape cultivars. So, we may see this vine growing free and wild here in California, but its genes are carefully cultivated in parts around the world.