At the risk of counting our chickens before they’ve hatched, I think we finally have grape vines that are immune to Pierce’s disease. Pierce’s disease is a fatal condition spread by sucking (and sucky) insects known as sharpshooters. Once a vine get it there is no cure. Pierce’s is why your glass of California wine may one day be genetically modified.
Over the years we’ve lost too many vines to Pierce’s to count, so I’m relieved to say that the ones we have seem to be immune or at least very resistant to Pierce’s and are now producing fruit.
LA County’s plant pathologist spent a half hour on the phone with me a few years ago telling me about how Pierce’s disease works. He told me not to even think about planting a vine in Southern California that is not immune to Pierce’s. After so many failures I decided to follow his advice. Here’s the vines we ended up with:
This monster has completely covered an ugly chain link fence. One of my garden duties at this time of year is beating it back, otherwise it would swallow our house and the neighbor’s. For some reason it has never produced any fruit (I think it may be male). From the Las Pilitas Nursery website:
California grape is a deciduous vine to 30′. If this grape has no support it will make a nice groundcover and can cover a large greenhouse in 4-5 years. It has clusters of small edible grapes. Bees love flowers. It grows along streams and in seeps throughout much of central and northern Ca. We’ve seen it in the Sacramento River bed, along the Sierra foothills and on I-5 at the Grapevine. It has done fine here and in coastal gardens. It likes regular moisture but not to be wet and full sun or a way for it to get to full sun.
Vitis californica tolerates sand, clay and seasonal flooding.
Vitus Californica ‘Roger’s Red’
We picked up this vine from the Theodore Payne Nursery to cover the arbor in our backyard. Roger’s Red puts on a showy display of red leaves every fall. And it has produced abundant fruit this year. One source I found noted that this vine is “highly resistant” to Pierce’s. From the Theodore Payne website:
Jerry Dangl at U.C. Davis has recently conducted DNA analysis of Vitis ‘Roger’s Red’ and has determined that it is a first generation hybrid (F1) between the native V. californica and a wine grape (Vitis vinifera) cultivar known as ‘Alicante Bouschet’. This grape, ‘Alicante Bouchet’, is unusual in that it has both red skin and red flesh – most red grapes and red wine gets its color from the skin only.
This mysterious vine came from the equally mysterious Papaya Tree Nursery. The talkative and knowledgeable owner of Papaya Tree said that this vine is immune to Pierce Disease, and it appears that he is correct. We’ve had it for several years now and there are no signs of disease. We got our first delicious grapes from this vine this year. From the Papaya Tree Nursery website:
‘Pearl River’ is a very vigorous producer of first quality grapes that reach up to 24% Brix(Sugar). They are seeded but the flavor and aroma is so strong that most prefer it to seedless varieties. A unique advantage the ‘Pearl River’ grape has over most other varieties is it’s immunity against Pierce disease . . . Although technically classified as a table grape, top quality award winning specialty wines have been made with this variety.
I’ve said it before and I’ll say it again. If you live in sharpshooter country (warm parts of the US and Northern Mexico) consult your local extension service and find a list of Pierce Disease immune varieties that will work for your area.