GRAD® Clone 1 Viognier

Simply the best Viognier clone in Australasia for both wine quality and provenance.

GRAD® Clone 1 Viognier in Brief:

  • This clone is a GRAD® re-selection of what my research has led me very strongly to believe is an outstanding Californian producer’s Viognier line sourced from Chateau Grillet old vines material.
  • Rolls Royce clonal line with exceptional Northern Rhone provenance unparalleled and unmatched by any other Viognier clone in Australasia.
  • The GRAD® Clone 1 Viognier foundation vines have P.C.R. tested negative for all viruses except the benign RSPaV1 virus. All Stanmore Farm mothervines are made from the GRAD® foundation vines and have consistently tested negative for GLRaV3 by E.L.I.S.A. in accordance with the N.Z. Grafted Grapevine Standard.
  • Trialled by GRAD® in North Canterbury, the GRAD® Clone 1 Viognier has proved to be early ripening, giving weighty (but not overblown or flabby) generous wines with peachy characters. Underlying Bartlett pear, lemon meringue / lemon curd notes and quinine mineral undertones add distinguishing elements of complexity (often producing wines arguably not unreminiscent of Chateau Grillet, which is most probably the source of this genetic line).
  • The GRAD® Clone 1 Viognier gives excellent flavour development right from veraison if leaf-plucked at bird-shot berry stage (just after flowering), giving bunches with superb burnished golden berries that have exceptionally refined and complex flavours with rich ripe phenolics, balancing gentle acidity, and low-moderate pH.
  • Medium-sized bunches of medium-small berries: no huge berries and bunches (and correspondingly low-flavoured) crops; or, alternatively, disappointing (and often uneconomic) hen and chickens bunches.
  • Low bunch-rot susceptibility: has held and ripened well in North Canterbury in cool autumns with persistent heavy rain.
  • Robust, hardy, but readily balanced vines with good drought tolerance and excellent suitability for utilisation in New Zealand cool climate vineyards from Martinborough to Central Otago, but also performing very well in Hawkes Bay in the Gimblett Gravels.
  • Vines grafted with GRAD® 1 Viognier are available in New Zealand through Stanmore Farm nursery under license from GRAD®.
  • E-mail for orders or inquires:
    Phone: 0800 Stanmore (0800 782 666)
  • Mobile: 027 544 0140
  • For further information and advice on the suitability and use of this exceptional Viognier clone in your vineyard, contact Dr. Gerald Atkinson at
  • A comprehensive non-propagation contract must be signed off as part of your purchase order.
  • Download 1 page PDF Fact Sheet on GRAD 1 Viognier



Just half a day before all its source vines were pulled out, I was given a bundle of cuttings of this Viognier clone by an employee of the vineyard where it was originally grown. I had no involvement whatsoever with its importation (in the late 1980s or early 1990s), and after receiving the cuttings I spent a good number of years researching their real origins. The story that had been proffered by the vineyard where this Viognier was grown had a number of rather dubious aspects, and although I eventually tracked down its import trail through quarantine, there is little or no doubt that its identity and provenance were highly obscured upon its arrival in New Zealand and thereafter. What is certain however is that this material came from California, but although it was sometimes claimed it was ‘UCD 1’ Viognier, it characteristics, and its Californian connections and provenance, never matched this claim. In addition, there were impossible anachronisms involved in the story that was attached to this clone, and in the end they give away its real identity and its overwhelmingly likely original, ‘Rolls Royce’, source in the Northern Rhone.

My research has convinced me that in California in the 1980s, there was only one line and source of high health Viognier, despite there being a range of ‘imports’ of the variety around that time. Indeed, in recent years, and not least because (one strongly suspects) of the statute of limitations taking effect, it has become more or less openly acknowledged that all of the ‘pioneering’ Viognier clones introduced to California in the 1980s entered the U.S. without necessarily going through correct legal and administrative channels. Unfortunately, and as the performance of the likes of the Calera, Phelps, La Jotta, Howell Mountain, Richie Creek, and other original Californian Viognier plantings demonstrated, virus infection was an overwhelming feature of the early introductions. This was due to two factors: most of the initial imports were virused at their French source; but others, alas, were from very fine health sources but were field-grafted in California onto virused vines (Cabernet Sauvignon being a frequent choice for such grafting-over). As a result of these factors, poor fruit set, painfully low crops, uneven ripening, and weak vines were overwhelmingly common in the pioneering plantings — with, in my view, just one  exception which I’m convinced is the source of the GRAD® clone 1 Viognier. Indeed, with the exception of this source, it was not until U.C.D.’s Foundation Plant Services obtained ex- Calera Viognier via the Geneva research station in New York and successfully heat-treated it, that there was any high health Viognier in California. (So the source of the GRAD® material was the first such line; the U.C.D.’s was the second.) In turn, this creates a time-line for vine development and wine production and assessment which exposes the story that the Viognier cuttings I was given were ‘UCD1’, despite the fact that that clone was available in the early 1990s for importation to New Zealand (and was indeed imported by several other parties).

My research convinced me that when it was imported in the late 1980s or early 1990s, the Viognier I had been given was very much a ‘known quantity’ as to its wine quality. Indeed I have no doubt that it had been used to produce outstanding and highly impressive wines in California for a number of years before it was imported to New Zealand. My belief is that the importer took a very strong liking to one producer’s Californian Viognier in particular and resolved to introduce their material to this country and grow it. To give credit where credit is due, a good measure of qualitative oenological discrimination is shown by this: the producer in question was probably the only winemaker using high health Viognier vines in the U.S. and California at the time, and those in the know soon became well aware, one suspects, of their vines’ exceptional Northern Rhone provenance. As it were ‘two and two were put together’: high health vines planted on clean stocks, and impeccable genetic quality from a creme de la creme Northern Rhone grower; this combination made this producer’s Viognier really stand out.

To this it must be added that during the 2000s I had numerous opportunities to study the UCD1 Viognier national foundation vines then held at Rowley Crescent in Blenheim. As with many other varieties, it was soon evident to me that Viognier clones have a definitely discriminable level of morphological distinctiveness: in many cases they can be told apart by close and careful ampelographic examination. It was, for instance, easy to distinguish the foundation UCD1 Viognier clones from the (Grapevine Virus A -infected) KHT Viognier grown beside it at Rowley Crescent. In particular, the UCD1 is a very vigorous clone — never mind the ease with which its wines can be distinguished because of their frequently low aroma and flavour, simplicity, and usual lack of quality. In turn while the KHT clone looked, in its finer characteristics, more like the GRAD®1 Viognier I was growing in North Canterbury and at my r&d nursery in Christchurch, KHT never looked as robust, and especially so under water stress. No doubt this is due to the fact that the GRAD®1 clone is a very high health line while the KHT has a formerly PCR-undetectable form of GVA and simply should not be grown by anyone because of the serious disease implications this virus carries, especially for Viognier and Syrah, as well as for decline and failure in graft unions. One could also point out that the provenance of the UCD1 and KHT lines is far inferior to that of GRAD®1 Viognier: the former two are, and derive from, very ordinary genetic lines (and very especially so for UCD1 in my opinion); by contrast, GRAD®1 has creme de la creme origins — as its trial wines also have shown.

The most definitive element of the case for the exceptional quality and provenance of the GRAD® 1 Viognier clone comes however through the detailed evidence adduced in Patrick Comiskey’s outstanding 2016-published book American Rhone: How Maverick Winemakers Changed the Way Americans Drink¹.  Comiskey details how one Californian producer in particular  had highly demanding selection standards for the range of Rhone vine material they obtained, and he also notes that the vine health and wine quality associated with their selections is second to none in the U.S.  Comiskey also reveals that Chateau Grillet is the foremost-likely source of this producer’s Viognier selections. This all fits with what I have seen in the numerous years that I have grown and trialled GRAD® 1 Viognier, and it explains the distinctiveness and exceptional wine quality this clone delivers. Today, there remains simply no better, or finer-provenanced, clone in New Zealand or Australia.


Health status

GRAD® 1 Viognier has been multiple PCR tested and has been shown only to have a weak strain of the benign RSPaV1 virus. All mothervines at Stanmore Farm come from foundation vines that have also (since their initial PCR tests) tested negative for GLRaV1,2,3, and GVA by ELISA. Subsequently, the mothervines held by Stanmore Farm have also been regularly ELISA tested and are negative for GLRaV3 in accordance with the New Zealand Grafted Grapevine Standard’s requirements.



The GRAD® 1 clone of Viognier is very a robust but not over-vigorous, grower with proven excellent drought tolerance. (Grafting to GRAD® 106-8 or GRAD® 44-53 rootstocks is highly recommended, although I have also produced very good vines of the GRAD® 1 clone of Viognier on GRAD® 125AA.) Growth follows a cycle similar to mid-period Pinot noir clones, with broadly similar budburst and flowering, and so it is a little earlier than compared with the nine GRAD® Syrah clones (and usually begins flowering just before, or at the same time as the earliest of these). The upshot of this is very simple therefore: if you can grow and ripen mass-selection Syrah you can even more readily grow and ripen GRAD® 1 clone Viognier.  A controlled measure of water deficit — while allowing sufficient soil moisture for ongoing photosynthesis, and thus sugar accumulation, of course — is desirable during the ripening period.

Basically, any well-drained medium to low -potential site that is just that bit too warm (and dry, especially in autumn) for ideal Pinot noir ripening, and which has good shelter and thus good heat retention characteristics, will suit GRAD®1 clone Viognier well. Growth, as with Syrah, sees long whippy canes produced, but in particular, Viognier is a big producer of adventitious growth in both laterals and watershoots, and those who can’t be bothered doing (or paying for) canopy management work will not get the best out of any clone of Viognier from (at least) Hawkes Bay south, and especially in the South Island. I have for some time used a single curtain, single Guyot, downward-trained close-planted (5,000 vines / ha.) trellising system for Viognier (and Syrah), although tall VSP is O.K. too. Combined with the indispensable key factor of complete leaf-plucking of the fruit-zone in the fortnight after fruit-set, these trellising systems will deliver highly flavoursome, complex, and superbly textured wines with definite Condrieu overtones (or, in GRAD® 1’s case, often with Chateau Grillet-like minerality and complexity provided over-ripeness is avoided).

Those who struggle to achieve early physiological maturity in Viognier (and who claim it shows nothing until ca. 24 Brix) need to come to terms with the realities of proper canopy management for this variety. Certainly, in the South Island, and very likely in Hawkes Bay too, thorough and early leaf-plucking of the fruit zone after fruit-set to achieve good thorough fruit exposure is near certain to secure flavour development as early as 18° Brix, with physiological ripeness and flavour and aroma complexity and richness markedly enhanced compared with shaded Viognier fruit. I have trialled and used this approach in North Canterbury for well over a decade now with exceptional results. And if you have to ask about ‘sunburn’ you (1) don’t understand the highly positive effect of early fruit exposure and especially UV light on grape skin development; and (2) you are simply are living in the pre-scientific dark ages — as recent publications by Richard Smart et al continue to demonstrate regarding post-fruit-set leaf plucking and its connection with superior fruit quality. ‘Sunburnt’ fruit in New Zealand conditions is virtually always the result of hasty and sudden exposure of developed (pea-size or larger) berries due to clumsily-coordinated — and most especially late — leaf-plucking that exposes developed berries to intense direct sunshine. Berries exposed at bird-shot size, just after fruit-set, grow and develop in the sun and their skins quickly and lastingly thicken and develop resistance to UV and heat burning in all but the most extreme dry and hot conditions (by which I mean those closer to the Australian Riverland than ever to N.Z.).  As Professor Nelson Shauliss (Richard Smart’s Ph.D. supervisor) told David Jackson about leaf-plucking and ‘sunburn’ in the 1980s when he visited the Lincoln vine trials “I think you’ll find … that if you leaf-pluck early enough, you won’t get it.”


Qualitative potential

I regard Viognier as a cruelly and most unwisely under-rated and misunderstood variety in New Zealand. Correctly grown, which means using proper canopy management as described above, Viognier can produce, and indeed has produced, some of the very best white wines made in this country. (Never let it near a winemaker who acidifies its musts however!) In 2019 I conducted an extensive tasting of New Zealand Viognier going back to the 2007 vintage. Barring several Herzog wines (none of which impressed unfortunately — not least because of their corks and the clone used I suspect) all were under Stelvin seal and none of these wines, even at up to 12 years of age, had peaked. Many were strikingly superb and showed wonderful varietal character and generosity. Condrieu of mid-rank ($75 to $100 or more) failed to dent this comparison: the N.Z. wines outshone them, and only by going to the absolute tête de cuvée finest of the appellation would the flights of selected N.Z. Viogniers under Stelvin be overshadowed. At present, the potential of the variety is however being grievously overlooked in this country — and particularly now, when Condrieu prices continue to escalate and its supply shrinks in the face of climate change induced harsher conditions in the Northern Rhone.

Of the clones now in New Zealand, GRAD® 1 Viognier leads the pack as having the finest bloodline and offering the greatest finesse and quality potential. While the relatively recently released E.N.T.A.V. – I.N.R.A clone 1051 has impressed me as a worthwhile ‘runner up’ it is nonetheless notably shaded by GRAD® 1, especially for the latter’s ability to produce wines with extra subtlety, complexity, balance, and potential longevity. By comparison, I cannot recommend UCD1 Viognier at all under any circumstances, and neither should HTK or KHT (whichever acronym / abbreviation you want) be grown, due to its GVA infection. The various lines of 642 (excluding UCD1 wrongly re-identified as 642) are fundamentally an ‘industrial’ proposition: a very fertile genetic line that often needs a lot of warmth in N.Z. to ripen its, at best, mid-level-quality crops. There is very substantial scope therefore for premium and super-premium Viognier to be produced in N.Z. if the finest clones and good viticulture are used. Moreover, while the domestic market here remains untutored regarding this variety, it is in any case hardly the ideal place for Viognier at present. Instead,  European, Asian, and Californian markets continue to show good interest in alternatives to increasingly scarce and ever more expensive Condrieu. Viognier contains much the same compounds as Pinot and Gewurztraminer that neutralise capsaicin in chillies, and it is a wonderful food wine therefore with Asian cuisine, or rich Italian, French or other Mediterranean seafood dishes and cheeses. It is also very amenable to quality vegetarian cuisine. Very real export market opportunities thus present themselves for quality N.Z. Viognier — at good premium prices — and the GRAD® 1 Viognier clone should be your first choice for quality and class.

To this I would add three further crucial caveats however:

  1. NEVER acidify Viognier musts or wines: accept the fruit’s pH and acid where it is when it is flavour-ripe and concentrated; it’s not Chenin blanc or Riesling, and added acid in its musts sits (as also with Gewurztraminer and Muscats) very ill indeed against the rich phenolics of the variety;
  2. Viognier does not need, and more often than not is overborne upon by, new oak; older oak suits it well;
  3.  Viognier behaves unusually for a white varietal wine relative to Oxygen, and its wines will open out and change for 3 – 4 hours (and good young Condrieu etc. for even longer) in a decanter: it should NEVER be shown, tasted, seriously sampled, or drunk (especially in its first 5 years or so) poured straight out of the bottle; decant it and breathe it and wait until it becomes fully aromatic and the fruit on the palate has opened out; the wine will frequently change and change again (and continue to open out and develop aromatic and flavour richness) over several hours breathing. This is probably the single greatest wine-handling and presentation error both wine-producers and consumers make with Viognier — failing to give it air and time in a decanter to open up.


Ripening period

GRAD® 1 Viognier has proven to be an early ripener in North Canterbury trials, even in vintages where cold wet weather has set in at the end and threatened to ruin many other grape crops. Grafted on GRAD® 106-8 or GRAD® 44-53, this clone tends to mature after Pinot but a touch before comparably cropped mass-selection and GRAD® clone Syrah vines. Ripening is also enhanced by carefully controlled soil moisture deficit leading to a touch of ‘bagging up’ as the Australians put it (i.e., moderate berry shrivel) from about 22 Brix onward. I have never found it necessary or advisable, either, to take GRAD® 1 Viognier to surmaturity — above 24° Brix (if not simply ever above 23.5°): this does not give wines with enhanced oenological potential; Californian-style ‘over-fatness’ and clumsy, alcoholic, ‘blowsiness’ come with such surmaturity. With a top clone like GRAD®1 Viognier this is tantamount to overcooking a fine steak or a superb piece of tuna. In short: 23° Brix is a very reliable peak point of sugar ripeness for this clone provided it is produced on well-managed vines with good early fruit exposure.



Stanmore Farm nursery has a good stand of strong healthy mothervines of GRAD® 1 Viognier. Demand in recent years has continued to grow however and early ordering is advised. For current season and forward orders, contact Stanmore Farm for details regarding grafting quantities available. Use of cool-climate adapted highly drought resistant GRAD® 106-8 and GRAD® 44-53 rootstocks is strongly recommended for the GRAD® 1 Viognier clone.



Vines grafted with GRAD® Clone 1 Viognier  are available through Stanmore Farm nursery under license from GRAD®

E-mail for orders or inquires:
Phone: 0800 Stanmore (0800 782 666)  
Mobile: 027 544 0140

For more information about these clones, and for details regarding their use in, and suitability for, your vineyard, e-mail Dr. Gerald Atkinson at:

Grafting orders may be placed now for supply subject to budwood availability.

Please note that a strict and comprehensive non-propagation contract must be signed off as part of your purchase order.

GRAD® is a New Zealand registered trademark uniquely and exclusively used to identify the vines in the GRAD® vine collection. Use by unauthorised parties to identify any vine material, or other use for commercial gain, is an infringement of this trademark.

Genetic ‘fingerprinting’ and clonal traceability

Vine pirates BEWARE! It is now possible to genetically fingerprint, uniquely identify, and individually detect grapevine clones using the latest-developed molecular genetic sequencing techniques. See the breakthrough research paper by Michael J. Roach et al, “Population Sequencing Reveals Clonal Diversity and Ancestral Inbreeding in the Grapevine Cultivar Chardonnay”, published November 20, 2018 at


  • 1. Patrick J. Comiskey, American Rhone: How Maverick Winemakers Changed the Way Americans Drnk (Oakland, California: University of California Press, 2016).


Questions about this wine grape? Contact us.

Author: Dr. Gerald Atkinson

Company director, viticulturist, grapevine researcher and historian, and sometime wine-writer.