First Press
First Press is a casual, conversation‑driven, insider’s look at the people, business, and culture of wine. Hosted from the heart of Napa Valley by three wine industry professionals, the show explores what we know, and what we’re learning, about the world of wine.
Each episode blends real world vineyard experience, financial insight, and storytelling from the cellar to the boardroom. Whether you work in wine, dream about wine, or simply love learning what’s in your glass, First Press is your front row seat to the world’s most fascinating agricultural industry.
First Press
Episode 6 - Rootstocks!
Use Left/Right to seek, Home/End to jump to start or end. Hold shift to jump forward or backward.
A discussion on what rootstock is and how important they are to the industry today.
The overwhelming majority of the wine you have ever consumed came from vines that are two plants stitched together. Now that isn't a metaphor, it is quite literally two different plants stuck together. The part above the ground, the trunks, the shoots, the leaves, the grapes. That's your Cabernet, your Chardonnay, your Pinot Noir, etc. But then somewhere on the trunk, often not far above the ground level, there's a callus protuberance, a swelling in the trunk, like a scar. Below that is a completely different species of grapevine. That callus is a graft union, and the reason that it's there is one of the most important and fascinating parts of wine grape growing from the last 150 years. So today we're going to talk a little bit about rootstocks, where they came from, what it does, and why it's one of the most critical aspects of wine production today in the modern world. So let's start with a little history. The process of grafting is old. Our ancestors were utilizing grafting as far back as biblical times. And the idea is quite simple. You take a cutting from the plant you want fruit from, that's called the scion, and you join it to the root system of a different plant, the rootstock. You cut them so their tissues line up, you bind them, and if you've done so correctly, their vascular systems fuse together and create a unified plant. It may sound incredibly obvious, but one of the most important parts about grafting for wine grape production is this. The fruit that you get is entirely from the scion. So if you graft Pinot Noir onto an American rootstock, you get Pinot Noir grapes, not slightly American Pinot Noir grapes. The genetics of the berry, the skin, the aromatics, all of that comes from above the graft, which is a good thing because this affords you the fruit that you want with the aptitudes and characteristics of the rootstock necessary to thrive in the soil environment. The American wild grapes, species with names like Vitus riparia, rupesteris, berlandiari make small, seedy, aggressively flavored fruit. There's a quality in some of them that gets described as foxy, which in the wine world historically has not been viewed as a very favorable flavor profile. But with that said, they have one other thing that's going for them, one extremely important thing. They can survive phylloxera. Phylloxera is a tiny aphid-like insect native to eastern North America. Yellowish, under two millimeters, about the size of the head of a pin, its life cycle is fascinating. Multiple forms, some winged, some not, some on leaves, some entirely underground, and it can reproduce without mating, which means one individual can form a colony. And what it does is feed on grapevine roots. Now the American vines it evolved alongside had formed resistance to this feeding. When phylloxera pierces their roots, they wall off the wound, forming a hard corky barrier, the insect gets a disappointing meal, and the vine carries on. Vitis vinifera, the European wine grape, however, the species that gives us essentially every famous wine grape on Earth, has never encountered it before and had no answer to this feeding damage. So when phylloxera feeds on vinifera root, the wound doesn't seal, it swells, galls, creates rots, you get introduction of secondary fungi or bacteria, and the root system slowly becomes compromised. Over time, this damaged root system reduces grape quality and ultimately will result in the death of the vine. Now phyloxera got to Europe sometime around 1858. It was first recorded in France in 1863, down in the Languedoc, and then it spread to Rhone, Bordeaux, Burgundy, and eventually across the continent. The damage is hard to overstate. Estimates vary, but figures in the range of 40% of France's vineyards destroyed are commonly cited, and by the end of the century, something on the order of two-thirds of Europe's vineyards had been hit. In France alone, that's on the order of more than a million hectares. Entire regions stopped producing, growers went bankrupt in waves, and there was a mass emigration out of wine country. And for the better part of a decade, nobody really had a good idea on the cause. The insect was finally identified as a culprit in the late 1860s by a French botanist named Jules-Émile Planchon. Planchon, in combination with a committee of other French scientists and winemakers, set out to find a solution. What settled it was, of all things, a transatlantic scientific partnership. Charles Valentin Riley, the state entomologist of Missouri, knew this insect pretty well. He'd seen it on American vines, he confirmed Planchon's identification, he confirmed the American origin, and he pointed out the thing that mattered most. American vines can live with this pest. Meanwhile, the French government had put up a prize of over 300,000 francs for anyone who could produce a cure. And people tried everything. They flooded their vineyards, they injected soil with carbon disulfide, they performed bizarre cultural practices, they tried just about everything. But the actual answer had already been proposed by a couple of French growers, Leo Laliman and Gaston Basile, among them, and due to the controversy, it took many years to be adopted. But the solution was pretty clear. Don't fight the insect, change the roots. So the fix required a wave of work, crossing the American species with each other and sometimes with vinifera to combine phyloxera resistance with tolerance for European conditions. That's where the modern rootstock catalog comes from. Almost every rootstock in wide commercial use today traces back to breeding programs from roughly the 1880s through the 1920s, run by people whose names are now stamped on the rootstocks themselves. Corder, I'm gonna butcher these names, but that's okay. Millardet, Richter, Paulson, Rugeri, Telecki, and Cobra. And it worked. The vast majority of the world's vineyards today are grafted, and they've been so for over a century. One thing that I want to be clear is that the fear that grafting would somehow ruin or uh create impure representation of grape variety turned out to essentially be completely wrong. If you take one practical thing away from this episode, take this. Root stocks, their selection and how they work aren't random. It's not magic. They're usually combinations of one of or multiple of American species. And if you know the parents, you can more or less predict the child. Vitus riparia, the riverbank grape, grows along waterways across a huge swath of North America. Shallow-rooted, low vigor, likes water, hates drought, hates lime. Its great gift is that it ripens fruit early. It shuts down the vine at the end of the season, which is exactly what you want, somewhere cool and short. The pure selection that you'll see often is riparia glore. Vitus rupesteris, or the rock grape from places such as Arkansas, Missouri, Texas, has deep branching roots. It's drought tolerant, it's very vigorous. Its pure selection is rupesterus dulat, or often known as St. George. Vitus berlandiari is the third most famous vitis species for rootstock. And these are from the limestone hills of central Texas. So it's an incredibly lime tolerant plant. It has deep roots, it's very drought tolerant, and it thrives on high pH soils. One of the difficult things about it is that it is difficult to root from cuttings, which is often why you don't see it planted as a pure variety. It's very often just bred and crossed with another American hybrid species or American species. Now the crosses. So this is where it gets even more useful. So if you were to take riparian ripestrus, uh, it would give you a moderate to low vigor rootstock that is best suited for fertile ground where you don't want a monster vine. Things such as 3309C, 10114 are classics. 10114 in particular is a favorite for cooler, damper sites and for growers chasing early ripening. Uh a lot of winemakers really, really love 1014 because oftentimes um the vines uh can sometimes look a little rough. And rough-looking vines means good wine.
SPEAKER_01That's why my viney looks so shitty, because that's I think the rootstock that I use.
SPEAKER_02Was it on 1014? I think I did. So 1014, uh it I don't know if you want to pause. No, it's 1014 is uh by all accounts a very, very uh good rootstock. It's just if you have a very low water table or you don't have an ability to irrigate a lot, it's going to show its stress quickly.
SPEAKER_01Yeah.
SPEAKER_02Um, and so you'll just see this earlier than you might think from late summer, just the this basal yellowing just starting to split. That's exactly what mine looks like.
SPEAKER_01Yeah, literally, it looks so good up until April, May, all of a sudden boom, just starts to look really sad.
SPEAKER_02Yeah, the worst thing I could ever think of. Well, that's not not the worst thing, but like Merlot is a uh great variety that also And that's what I used. Is it is it Merlot on Merlot? Yeah, so you took you took a pretty heat sensitive uh relatively heat sensitive variety, like it it a leaf in the sun will start to fold on itself, yeah, and Merlot, especially, will start to go like this, and then on 114, it's gonna just look even worse.
SPEAKER_01So that's why my vineyard looks so sad. I mean, there could be other reasons, but um the soil has no nutrients in it. I need to nutrientify the soil. Yeah, yeah, it's uh something worth thinking about. Yeah, I didn't know that, so now I know I should have I should have talked to Cody first.
SPEAKER_02No, I so the cool thing is, is like you know, you can still probably still make great wine off. I mean, I don't know what it could possibly what it tastes like, but um, yeah, you might be able to make pretty good wine off it still. So I don't know. Winemakers love a lot of winemakers that I'll say a lot of winemakers love shitty looking vines. Yeah. Um and I'm not a winemaker, so I can't say that they're not they don't they don't have merit.
SPEAKER_01The idea is the more stress the vine has, the better the fruit has to be.
SPEAKER_02It's gonna be really concentrated, it's gonna be and I'm like Is it? I'm like, I don't I don't know.
SPEAKER_00It's like this dogma that they yeah tend to follow. Yeah, and like, oh, the more it struggles, the more concentrated.
SPEAKER_02It's like, well potentially struggle too much, but I mean yeah, exactly. Yeah, if you were to treat your kids that way, yeah. All right, let's just let's just power through this. Berlandiere riparia, that gives uh you a great deal of Lyme tolerance, um, especially in places like cool continental Europe, so SO4, 5BB Cobra, 5C Telecchi, 420A, etc. Um, Berlandieri rupesteris is a hot and dry uh rootstock cross, deep roots, drought tolerant, high vigor, and a tendency to delay ripening. So 110R, 101 uh or excuse me, 1103p, 140R. These are rootstocks of southern Italy, Spain, southern France, and increasingly anywhere that's getting hotter, like the Central Coast. Now, this brings me to a very special rootstock that many in California, I'm sure, remember, Sonoma, Napa, especially. Uh, there was a rootstock called AXR1, which was a cross of a benefera variety called Aramon with ripesteris, and it was terrific to work with. It was vigorous, it was easy to graph, it was very productive, and best of all, you had the scientific backing of UC Davis that recommended it widely for growers and wine producers in Nap and Sonoma in the mid uh 1900s onward. Um, and thousands of acres went in. The problem was the vinifera half, because if half of your rootstock is the species that phylloxera loves, your resistance well isn't. In 1982, a strain of phyloxera turned up in Napa, vines started dying, and Davis withdrew their recommendation in 1989. Nurseries stopped propagating it in the early 90s, and Napa replanted roughly two-thirds of its vineyards. Across Nap and Sonoma, together the affected area was somewhere north of 50,000 acres, and total cost across California has been put north of a billion dollars in loss. Now, that's about the end of the history lesson, mostly because we're at the point in time where uh people are still alive today that live through that time, they would do a better job telling you about that experience. So go talk to an old farmer or winemaker. So phyloxar resistance, it's now the baseline. If you're not planning on rootstock, what are you doing? It's not what a grower is deciding between, you know, when they pick a rootstock. Is it resistant or is it not? It's it's gonna have some sort of phyloxar resistance for the longevity of your vineyard. Uh, what they're actually choosing is a set of different criteria. So they're looking at vigor. How aggressively can the vine grow? Too much, and you get a jungle, you get shaded fruit, herbaceous flavors, disease pressure, and a canopy that you are just going to be forever cutting back as you get into uh fruit ripening. Too little, and the vine can't ripen its crop. A grower on rich valley soil may want a low vigor rootstock to calm things down, while a grower on thin, gravelly soil may want a more vigorous one to ensure that they have a full canopy to ripen their crop. Another factor would be rooting depth and water accessibility. So, how deep are those roots gonna go? Um, how well are they going to be adapted to getting down deep into the soil profile, especially as you get into the dog days of summer? That's gonna be very important increasingly with warmer weather. So, soil chemistry as well, another important factor: lime tolerance, salt tolerance, and nutrient uptake. Some stocks are notably better at pulling in potassium or magnesium, which has effects later on, uh, all the way up into the wine's vinification. So having the right one uh is important. Other pests, such as nematodes, there's varieties that do better against dagger nematode and other nematodes that have pest pressure and disease for your grapevine. It's very, very important that you, I mean, other than selecting the site with which you are going to plant a vineyard, this is the second most important choice. Where am I going to grow my grapes and what rootstock are they gonna be on? If you make that, if you don't do a good job in doing that, the next 20 to 30 years uh of your vineyard's life could be a massive headache for you, your farmer, your winemaker, etc. So a natural question arises does any of this end up in the glass? Can you taste the rootstock? Is it that important? And the honest answer is well, indirectly. Rootstocks are a tool in the arsenal of the wine grower. It's how a grower gets the vine into balance relative to the environment in which it's planted. So everything favorable downstream depends on that balance, but you're going to have a hard time determining in a blind tasting what rootstock's influence is present in your wine. The next time you're in a vineyard, crouch down, take a look at the base of the trunk, and try to find the graft union. Above it, you're going to see 2,000 years of human obsession with a particular flavor, a specific typicity. And below, a wild American vine doing its job thanklessly, because in 1863, an insect decided to get on a boat.
SPEAKER_01So what you're saying is America saved the wine industry.
SPEAKER_02Like America often does, it creates a problem and then saves.
SPEAKER_00Oh, you're right, because they're from because they're from your people. We we destroyed and saved their industry at the same time. That reminds me too. There was uh I was listening to an interview with um one of the members of the Hugell family. And so for a bit of time in Alzhas, they planted hybrids and they were referred to as a a three-man wine, one man to drink it and two to catch them from fainting over how bad the wine was.
SPEAKER_02Bummer. It's uh yeah, it's I I just don't know what you could do without this type of intervention. One of the things that I didn't include was there was essentially two schools I thought. It was when they discovered what phylloxart was and that it was a problem, it was, oh, we gotta graft it onto these um American rootstocks. And then the other half or the other side was like, hell no, absolutely not. We're just gonna fumigate our soils, or we're just gonna do something. Like, we need to keep uh French varieties uh uh vanifera unrooted, um, and we're just gonna treat the soil. And obviously that didn't pan out. Um people were doing some wacky shit too, like planting stuff around the roots, like to be burying toads or something like that.
SPEAKER_00I I I've read something like that.
SPEAKER_02I was like, that's just moronic.
SPEAKER_00Yeah.
SPEAKER_02These micro, like virtually micro, you're like, you have to have a hand lens to see them. I'm like, yes, these these toads buried in soil will definitely eat millions of these bugs.
SPEAKER_01So that poses a question. There's a large community of vineyards that in especially in the United States that tout old vines, and a lot of these old vines are planted on their own roots, meaning no rootstock, because something about the soil is so well draining that none of these microscopic nematodes or phylloxar can live in the soil. Is that really then at the end of the day, more of just a marketing and history gimmick to it more than it is anything else? Or from a growing perspective, does it make any difference being on its own roots?
SPEAKER_02I I wouldn't think so. What I would say is when that vineyard gets pulled out, it's not going back on rooted.
SPEAKER_01Yeah.
SPEAKER_02And um even let's say you had a vineyard that uh had soil conditions that were not favorable for uh phylloxera. You got a 90-year-old vineyard, for whatever reason you cannot continue to maintain it, whether it be for financial reasons or it's just so old and sick that um it it just it you can't farm anymore. I would wager that the owner of that property or the farming company or the winemaking team, whatever, whoever's responsible for planting back that vineyard is probably not gonna go back in on own roots. Um the way that we thought about farming now, especially in some of these more premier growing regions, and when I say premiere, I mean price point, not necessarily quality. Um, although there is a high quality associated oftentimes with Napa and Sonoma, you know, it's too expensive to take that risk.
SPEAKER_01Yeah, exactly.
SPEAKER_02I'm going to invest millions of dollars in a vineyard um for the material uh and the labor and the chemical and the time. I can't afford to risk having this thing collapse.
SPEAKER_00Is it true that St. George was one of the first root stocks to be developed to be resistant to phylloxera? Or that's how it got its name, because it was like St. George killing the dragon of phylloxera, even though nothing kills phyloxera.
SPEAKER_02Yeah, that's interesting. Um, I don't know. Sometimes people will say, oh, it's immune to, or it's it's not affected by. And the reality is, is these rootstocks are just tolerant of, they're just resistant to. Um it's it's they can deal with it. Exactly. It's it's not like they're these magic plants that somehow are bulletproof to feeding damage by phylloxera. It's just they just for for uh thousands of years um have created a strategy by which they can survive feeding damage from phylloxera.