227: Andy Walkers’ Pierces Disease-Resistant Grapes are a Success at Ojai Vineyard

In the 1880s, Pierce’s disease caused a devastating, total collapse of the Southern California grapevine industry. Today, growers have hope for the future thanks to new varieties. Adam Tolmach, owner of Ojai Vineyard, planted four of these new varieties as a field trial on a plot of land where Pierce's disease wiped out his grapes in 1995. 

Pierce’s disease is a bacterium spread by insects, typically a sharpshooter. One bite and the vine dies within two to three years. To develop resistant varieties, Andy Walker of the University of California at Davis crossed the European grape Vitis vinifera with Vitis arizonica. 20 years later, commercial growers have access to three red and two white varieties.

Listen in to learn how Tolmach’s experiment is a success both in the vineyard and with customers. Plus get tasting notes for the new varieties.


Vineyard Team Programs:

Get More

Subscribe wherever you listen so you never miss an episode on the latest science and research with the Sustainable Winegrowing Podcast. Since 1994, Vineyard Team has been your resource for workshops and field demonstrations, research, and events dedicated to the stewardship of our natural resources.

Learn more at  


Craig Macmillan  0:00 

Our guest today is Adam Tolmach owner and winemaker of Ojai vineyard. Thanks for being on the podcast, Adam.


Adam Tolmach  0:06 

It's my pleasure, Creg. Great to be here.


Craig Macmillan  0:09 

I want to give a little background. Before we get into our main topic. We're gonna be talking about Pierce disease resistant grape vines today, but I think your location has a lot to do with how this came about. I don't think it's an overstatement to say that you are a pioneer and innovator and quite frankly, legend in the history of the Central Coast. And one of the pioneering things that you did was you planted a vineyard in Ojai, California, why Ojai? And what is the what's the environment, like, you know, hi.


Adam Tolmach  0:33 

Ojai because in 1933, my grandfather bought a piece of property in Ojai while I grew up in Oxnard, we, you know, on weekends, we'd come up here and chase lizards and snakes and stuff like that. And so I'm pretty familiar with the area and then I lived in Ohio for a few years after I finished studying at UC Davis getting a basically a viticulture degree. I came down here and and ran a truck farming operation, we grew vegetables and sold sold them in a roadside stand. And after doing that for two years, I made $4,500 After two years of worth worth of work. So I had said well maybe I should try to get a job in my my field. So my second job in the field was was working at at Zaca Mesa, 79 and 80. And then so as far as the place to plant grapes, you know, that's the reason we're in Ojai because we the family owns property.


Craig Macmillan  1:30 

What is the environment like in Ojai? Because I think it's a little bit different than many grape growing regions.


Adam Tolmach  1:34 

Yeah, you know, it's actually not that different than I would say the east side of the Santa Ynez Valley like the happy Canyon area or you know, or Paso Robles. Really as far as climatic goes. thing that's a little bit different about Ojai is the wintertime lows aren't as low as they are up in the Santa Ynez Valley or up in Paso. And that's that's a big deal, especially when it comes to Pierce's disease.


Craig Macmillan  2:01 

That's where we're gonna go next. When you planted, were there things that you were expecting? And then were there things that came out that were unexpected? And then thinking maybe Pierce's disease is one of those?


Adam Tolmach  2:11 

Well, yeah, certainly was, you know, as I've started, you know, pretty ignorant. As young people tend to be, I knew that there was a history of winemaking and grape growing in Ojai, which pretty much died off with prohibition. Actually, after Prohibition, there was a good sized Zinfandel vineyard that ended up being buried in the bottom of Lake Casitas. That sort of what I knew a little bit about grapes. And I didn't really realize it. Pierce's disease also worked into all that that, you know, you plant a vineyard around here, and it's pretty difficult to keep them alive  for the long term.


Craig Macmillan  2:48 

Just cover the bases. What is Pearson's disease?


Adam Tolmach  2:51 

It was originally discovered in Anaheim, California, you know, back in the I believe it's 1880s or so there were 10s of 1000s of acres of grapes in that area 10 or 20 or 30 years out. In fact, it was a much bigger growing area than, than say Napa, up north was for for grapes. And those vines all died. And at the time, it was called Anaheim's disease. Yeah. And so later on, Mr. Pierce, I think, discovered a little bit about the disease. And what we know today is that it's a bacterium that is spread by an insect, typically from a sharpshooter. But there are other insects that also spread this disease. In our case, we're not too far from a river habitat, a riparian habitat, these bugs like lush, green growing areas, and they live in the river bottom, all they have to do is get blown by the wind up to our place. If the insect is carrying this bacterium, it just takes one bite. And then within two or three years, the vine dies because basically the bacteria clog up the water conductive tissues.


Craig Macmillan  3:59 

Exactly. When you were first addressing this problem. What kinds of management things did you do to try to manage this?


Adam Tolmach  4:06 

Well, we didn't back then. And as we are now we're reasonably committed organic growers. So you know, we don't use herbicides, we don't use insecticides. And you know, I learned as the vineyard died, basically what was going on? So we didn't really do anything, preventative wise. And so the vineyard just slowly declined, right, which is pretty sad thing to see that really considering that I planted you know, every one of the vines in the beginning back in 1981.


Craig Macmillan  4:37 

Yeah, yeah, exactly.


Adam Tolmach  4:39 

And then so we went on, after that, and for years, you know, so the vineyard grew from planted in 81. And then in 1995, after the harvest, we pulled the vineyard because it's so much of it was gone from the disease and then and then there are many years where we you know, didn't grow any grapes on our property. We purchase grapes from mostly, you know, I'm from the Ohio area a little bit, but also mostly from the Northern Santa Barbara County. That area from Santa Maria to Lompoc is really where ideal grapes grow. But I'd always have a hankering to have, you know, to continue to have a vineyard here because we do have the winery right on site here. Close friends and family knew Andy Walker, who was the one who was developing these grapes that were at UC Davis that were resistant to Pierce's disease. You know, I kept kind of pushing the friends to see you if I could get some of these cuttings or plants. And then finally, really just a year or two before they were actually officially released to the public for sale. I was able to get enough to plant a very small vineyard here which is just 1.2 acres, and it's planted to four different varietals. All four of them were developed by by Dr. Walker that He basically took Vitus vinifera the European grape variety and crossed it with Vitis Arizonica in Arizona is a native of the southwest and there are some plant breeding advantages to using Arizonica, it carries the resistance, they can somehow see that really well in my days of knowing how all this stuff works is a little bit past but but there were there are certain advantages that Arizonica provided a one of which was it's a pretty neutral tasting grape. And then also the the second thing was, they were able to pick out right away if they did a cross whether they can tell whether it had the resistance or not. So they did worked on that he's worked on it for about 25 years. And in the end, he had these varietals that were that are 97% vinifera. And only 3% of the American stock, which is pretty important for the flavor profile. They taste very much like the different wines, not like you know, the native wines.


Craig Macmillan  6:53 

And then you've expanded that vineyard, I'm assuming you had your trial vineyard and expanded it.


Adam Tolmach  6:57 

No, no, no, it's all it's all we have is this 1.2 acres. Yeah. And so you know, we mostly make conventional grapes. So you know, we make Pinot Noir Syrah Chardonnay Sauvignon Blanc and a few other things. And we get some of those grapes from the Ojai area and in spots where they're when they're where there's less Pierce's Disease pressures. And then also up in Northern Santa Barbara County, as I said before, and so yeah, we're just we're still working with, with what we have, we found that the vines are very productive. And we are currently making really just the right amount that we need to provide our direct customers with the wines. It's been a fabulous experiment and great fun, because basically knew, but nobody knew how to grow these grapes. And each grape variety grows a little differently. And so then that was that was a real challenge there. Because I had grown grapes in the same spot before I knew some of the problems and challenges and they had a real strong sense of how I wanted to grow them a second time around. And so that was super helpful. But it's still they still were unknowns for for us, you know, the bigger the crop level, all that stuff, the taste. And then so that was great fun. And then in winemaking wise, Andy Walker had done a number of public tastings of these experimental varieties, I think I went to four of them, where they're mostly were three gallon lots that were fermented by the university. And so it's a little hard to tell from that, but they just seem like there was some potential there. Interestingly, Camus vineyard early on, got some of the vines have this one variety paseante noir. And so they made a really almost commercial size lot of that one, and I was able to taste that before I planted it. And while their winemaking style is a little different than mine, there was it was clear that there was like lovely potential in those grapes. So that was encouraging. But still, we knew nothing, we had no idea. It's still a work in progress it. You know, after five years of producing wine, there's a lot more to learn about how to best make these works. But so anyway, we planted four varietals one is passeante noir, which I think is sort of the best of the ones that I've I've tried. We also had a red, that is really it was never released to the public. So it's a you know, it's our own little thing. We have a small amount of that we call it Walker red. And then we have two whites caminante blanc and ambulo blanc and they're both to go back. Well to go on, I guess is the ambulo blanc and the caminante blanc are distinctively different. They're a bit on the Sofia and blanc side of life, I suppose. But not exactly. And then going back to the passeante noir that's I feel like it sort of tastes like a cross between between syray and maybe cab franc And then possibly some mouved you know, it's a little hard to, to read exactly what's there, but they're unique and different. And you know, in a world from 30 years ago, people wouldn't have known what to do with them. But these days, there's a lot of interest in unique grape varieties, you know, all over Europe, people are, are reviving ancient varietals that nobody's ever heard of, and they all have unique flavors and unique characters. Here are some newly bred ones that that are available now.


Craig Macmillan  10:27 

What is the response from consumers have been like?


Adam Tolmach  10:29 

Well, that's, that's been super encouraging. Because so you know, we're selling almost exclusively directly to our, our consumers, we have a tasting room, and we have, we do mailorder as well. And but I mean, it's been very positive, we've been able to sell out the wines, people seem to really enjoy them. So it that's been a thrill to, you know, have that consumer acceptance, I think it would be much more difficult if it was, you know, in a grocery store, for instance, but because nobody would know what the name meant. When we're able to hand sell it, it has not been difficult to sell. So that's, that's been super fun. Now, Dr. Walker, also, he had the idea that these varieties, you could grow them and use them as blending material, you know, like if you're making Cabernet Sauvignon in the Napa Valley. It's well known that in the Napa Valley near the Napa River, there's huge Pierce's disease problems. And so is one of his ideas is well you could you know, plant strips of of these varietals be able to have at use the ground productively and then blend them with Cabernet Sauvignon as long as you're over 75% You could call it Cabernet. But what's amazing to me is that the this Passeante Noir is really it's it's it works pretty well as a standalone varietal.


Craig Macmillan  11:41 

Were you tempted to to blend we attempted to use these as blenders? Or were you committed to single varietal all along?


Adam Tolmach  11:48 

I was much more interested in what they had to say. Yeah, so there wasn't very much interest in my part of of using them to stretch of wine or whatever to you know, to add to something else. It was an option I you know, if they weren't as good as they are, I would definitely could put them into you know, inexpensive bland we make it Ojai read or Ojai white. And so that was definitely an option. But I'm kind of thrilled that they you know, they're interesting enough, they can stand alone.


Craig Macmillan  12:13 

Do you think that you'll expand your planting?


Adam Tolmach  12:15 

Possibly right now, No, I've got too many things going on. And in this little vineyard year, being small as I do, I do all the pruning, and do some of the work out there. And so it's kind of a family affair. I'm not sure if I want to overwhelm my family with more. For our needs, we don't need too much more. As as things stand. We're we're pretty small size operation. And this is pretty much, well takes care of it. Interestingly, in the same vein, I own a small vineyard, up in the Lompoc area in Santa Rita Hills called Vaciega that's planted to Pinot Noir. And there's one area of the vineyard is kind of up on a little bit of up on a, a mesa or something in between, you know, above quite a bit above the river. The Santa Ynez river. But there's one small section of the property. That's right, basically, in the river bottom, it had been planted to Chardonnay and died of pierces within eight years of its planting. So it was pretty, pretty devastated. And so we actually planted the passeante noir down there and got our first crop this year into that world last year in 2013. And we're pretty excited by that. So really different climate to grow in. So you know, cool climate versus pretty warm climate. It seems pretty, pretty fascinating right now, I'm pretty excited by that. So we do you know, we do have more just not here in Ojai.


Craig Macmillan  13:43 

Would you commit like, what are you going to cultural notes on each variety? And then also what are your like winemaking notes on each variety because this podcast is growers and winemakers and we can get a little bit more technical if you like.


Adam Tolmach  13:54 

Oh, sure. Yeah, absolutely. Yeah. So Andy Walker released five different varietals, three red, and two whites. I have the two whites and I have only one of the Reds that are commercially released. And that one is paseante noir and paseante Noir is a very vigorous grower. We're on pretty rich soil, I mean, richer than you need for grapes, mostly eluvial stuff. You go down three and a half, four feet, and it's, you know, it's river rocks, and then there are shaley areas, but it's rather richer than you need. We haven't planted on one 114 rootstock which is quite deinvigorating. But in our site, it's still exhibits lots of vigor. And so the paseoante noir grows like crazy. We have planted pretty close together. So our rows are five and a half feet apart, rather than, you know, six or eight or 10. And I did that specifically, for climatic reasons, you know, you get these rows a little bit closer together. You get a fairly tall vertical trellis. And what you end up with is, is a little more shading. And we have this really narrow canopy, the grapes all get some direct sun, but just not for very long, a little bit in the morning a little bit in the afternoon, the rest of the time, they're shaded, also the ground is shaded a lot, because they are so close together. And I think that keeps the temperature down. And I think that's really better for quality. And that's, you know, my personal view on it. And, and that's worked really well we've never, we've never had a situation yet where, you know, it's gotten so hot that the grapes have rasined up, you know, just like overnight, it's not just not happened. So yeah, so here we have the paseante noir it's you know, it's a real vigorous grower, I have a quote on pruned it's incredibly productive. We've been dropping, you know, 50% or more of the grapes as a as a green drop every year and I think I need to double down and drop even more as it turns out, they really want to produce in part of its, you know, part of it is our rich soil, but I think they're also bred to be quite productive. So that's, that's really nice. You know, better than too little, which is, you know, kind of Pinot Noir is problem, generally speaking, the walker red is this one that nobody really knows about, but it's, it's a little more like if the paseante is is a cross between, in my mind a cross between Syrah and cab franc and the walker read is a little more Zin and Grenache kind of character grows a little more upright and with less vigor, a lot more like how Grenache grows. And then the two whites the caminante blanc produces these little tiny clusters that somehow end up always produced, you know, the yields are still high, even with the small berries, small clusters, they give a little bit of a blush to them almost, they're not completely green when they're fully ripe. And they have a really distinctive spicy character, they're quite interesting. And that one is the weakest growing, there's no bigger problem there, it grows along fine with it, it fills up the canopy, but just barely every year, because of the size of the clusters, you just don't expect there to be much crop, but it always turns out to be very generous. And then the other varietals is called ambulo blanc. And it's a little, maybe has a bit of Sauvignon Blanc, spiciness to it. But it also is it's got a much more sort of Chardonnay ish, like, produces large clusters. And it also grows vigorously. So it requires a lot of the trellising is really, really important. And so we spend a lot of time in the ambulo blanc and paseante noir, you know, weaving weaving the canes up, right.


Craig Macmillan  14:06 

Based on your experience, would you say, Hey, this is a great idea. If you live in a Pierce's disease area, you should definitely try this out.


Adam Tolmach  17:55 

Oh, yeah, definitely. Yeah. Because I mean, if the if Pierce's Disease is pretty strong, you're you know, you're left with, you know, having to use a lot of insecticides, and they're very bee unfriendly insecticides. And so, you know, we're able to grow here completely organically. That's worked out really well. So that's, that's, there's a great advantage there. I noticed in your questions at the you had to get sent me a list of questions. And one of them is like, what else should they be working on at the university? And definitely, my opinion is, you know, the biggest disease problem of grapevines in California is called powdery mildew. Everybody knows about it, why there aren't more powdery mildew resistant vines out out here yet is, is is interesting, you and every other trade, people that are kind of, you know, they, they praise, the new things that are coming along, the progress has been made in the wine business, everybody wants to just the old thing, just the way it's always been, that's a little bit of a stumbling block in a world where the climate is changing. So that's what that's why I really recommend that's what should be worked on is is resistance to powdery mildew, because it's not going to get better with climate warming. And also, it's it's the reason that we drive through our vineyards, you know, five or 10 times in a season just for powdery mildew control, it would be an incredibly great environmental thing if we could grow great tasting grapes and make great wine out of powdery mildew resistant varietals.


Craig Macmillan  19:27 

And I think people are starting to move that direction.


Adam Tolmach  19:30 

Oh, yeah.


Craig Macmillan  19:31 

But you're right, bring it on. You know, let's, let's try where can people find out more about you?


Adam Tolmach  19:36 

You can go to our website, you know, And there's, there's lots there's tons of information about about us and me and what we're doing and we have, there's a whole article on on the site about the Pierce's resistant vines that we're growing.


Craig Macmillan  19:52 

Very cool. Well, um, so our guest today has been Adam Tolmach owner, winemaker. Oh, hi, vineyard. Thanks so much for being on the podcast. This is great. Right


Adam Tolmach  20:00 

Yeah my pleasure I've been listening to your show now for quite some time I really enjoy it


Craig Macmillan  20:04 

oh good fantastic thank you and for all of our listeners out there thank you for listening to sustainable winegrowing with vineyard team


Nearly perfect transcription by