Elmer Swenson is a respected and nearly mythical figure in the cold climate wine growing community, but do we ever wonder what force was behind his success? He had his own motivations for breeding grapes which developed at an early age, and then later in life he greatly expanded the vine breeding work of prior generations. His ‘amateur’ vine propagation began in 1943 and continued when he was a dairy farmer and had full responsibility for the family operation. Upon retirement from dairy, Elmer went to work for the University of Minnesota as a fruit nurseryman and eventually, grape breeder. When he retired again, he continued on with his own hybridization work until it was no longer physically possible. How did he manage to be active and productive for so long?  My guess is that a steadfast and supportive spouse probably had a lot to do with it.

The Louise Swenson grape was named for Elmer’s wife and we have no idea at all if it is because they shared individual characteristics, symbolic or otherwise, or if the designation is purely honorific. Like Louise, who played a quiet but important supporting role in Elmer’s fruitful ventures, Louise Swenson, the grape, is not often seen out front in cold climate wines, but could provide a solid foundation on which to build proprietary white wine blends. I’ve had the chance to experiment with making wine from these grapes in a few vintages, blended in both still wine and bubbly, and have quite enjoyed working with it. It’s grown from Kansas to New Brunswick, with some plots in New York, and in the Lake Champlain Valley of Vermont. It’s a complex hybrid of Elmer’s ‘Kay Gray’ and ES 2-3-17 which itself is has ancestry in Seyval Blanc and some cousins of Brianna and Cayuga White. It is even said to make a fine table grape, for those Americans that can get past the seeds.

The compendium “Wine Grapes” has a listing that reports it as early to mid-ripening, drought susceptible but disease resistant with moderately acidic, light bodied wines having some pear, floral and honey aromas. My limited experience with the vines, fruit and subsequent ferments from the Cornell Trial Vineyard on the shore of Lake Champlain agree…in general. I did not take close notice of the vines in their early years but they have filled the trellis nicely and throw a good crop annually, although they do seem to need the whole season to mature. The bunches are beautiful and I’m kicking myself over the photo I did not take this past harvest. We’ve definitely had the pomme fruit show in the home winery, hewing to citrus when less ripe and yawing to faint labrusca when overly so, but always with a mineral, talc like finish. Figuring there were folks who had more time with Louise in the vine rows and in the tanks, I put a call out to one of the best resources I know for hands-on knowledge, the Cornell Cooperative Extension “Cold Country Viticulture” listserv.

The response and discussion that ensued was pretty impressive, and I wish that the comments were published in a forum or could be shared in entirety, because I believe it would represent the richest compilation of Louise Swenson guidance currently available on the internet. I’ll give you the short version as best I can. Louise is a slow starter and needs adequate water in the early years to establish properly, and as such heavy soils and fertile clay may be the best place to set roots. Spacing in the 8ft range on clay, and getting closer with more sand, may be appropriate to fill the trellis efficiently. With a healthy start, the vines will spread an open canopy, requiring minimal spraying. But DO NOT spray with sulfur as Louise is highly sensitive, and you will be very sorry to see the results. If treated nicely, one can expect 4-5 tons per acre, or more.  It seems to need ~2400 growing degree days to ripen reliably and even then the grapes will max out at 20 Brix, but they will lose their acidity in the process. Recommendation is to pick around 18 Brix then chaptalize to keep the freshness while avoiding the over-ripe wild grape bomb aromas. Batch blending barrel fermented, barrel aged, and malo-lactic treatments also provide options for house styles.

In the Champlain Valley, Hid-In-Pines mixes their Louise into proprietary wines while in Vermont three producers are leaning on Louise Swenson for some of their most notable wines. Lincoln Peak employs Louise in more than half of their Black Sparrow blend, while Shelburne Vineyard and East Shore Vineyard both do varietal wines that present like a kinder, gentler Sauvignon Blanc with apples and pears instead of pyrazine. The difference in temperature between the cooler eastern and warmer western shores of Lake Champlain may be telling dividing line on the ripening curve. Double A Vineyard Nursery out in Fredonia, NY seems to regularly sell out of their Louise Swenson stock, and Northeast Vine Supply in Vermont also sees both the demand and the potential. It would seem that Louise Swenson could be a good option for other areas of New York, like the middle and upper Hudson Valley, Schoharie Valley, parts of the Mohawk Valley, and even as a winter-kill backstop in the Finger lakes.

Cold hardy, highly disease resistant, reliable production and lovely bunches…what’s not to like? A number of growers who provided input for this piece professed true love for Louise Swenson, while others were still unsure about their commitment to the relationship. I have a hunch that Elmer knew what he had going for him, and that when it comes to cold climate wine making, that  Louise Swenson is going to be with us for the long term.


Hey Todd,

Let me be blunt…I love Louise.

In the vineyard it is a wonderful vine. Very open canopy, super disease resistant, heavy cropper, easy to manage. On the downside, it’s a bit scrappy and takes an extra couple of years to mature. Sensitive to water stress in first couple of years.

In the winery, LS produces a very nice light bodied, clean wine, with expressions of minerality and some tropical fruit. We get a lot of grapefruit and pineapple. The acidity is bracing and wonderful. We’ve been playing around w/ various amounts of skin contact and some subtle oak, for enhanced structure. I think there is plenty of potential here for partial MLF, barrel fermentation, and lees work, although all on a small volume that gets blended to bulk to keep that minerality and/or fruitiness upfront with the other complexities hiding in the background.

Happy Thanksgiving.

Ethan F. Joseph
Shelburne Vineyard


It’s to our experience the most pest-resistant or pest-free vine compared to any of the other MN hybrids we work with. It is shallow rooted though and takes a year…or tow …longer to really become established. Once established it really produces. We have been harvesting 5 plus tons/acre from our 2006 planted Louise for the past two years. It probably would have yielded that heavy a crop a few years earlier, but in its third year we sprayed it with organic approved sulfur which caused a complete defoliation of the vines!! We thought we killed them, but after a couple of years the vines came back strongly. DO NOT use Sulfur on Louise!!. The one pest suseptability is…watch out for grape berry moth late in the season. The plump and firms clusters at ripeness are a beautiful green-yellow…We harvest a 18 brix.

As for the wine. It ripens, for a MN hybrid with relatively low acid levels, so it can be fermented dry. Louise as a pure veriatal has become our dry white offering. It is a wonderful dinner wine with nice fruit, some nice minerality and a pleasant and somewhat complex finish. Even though it is light bodied we feel it has sufficient character and taste to stand alone as a verietal.

Ken Albert
Shelburne Vineyard


I have been growing Louise for some time now. Although I have been doing this in Minnesota it still may be of some interest to eastern growers which I think this list serves mostly. It was named for Elmer Swenson’s wife who hybridized the grape, by Tom Plocher and Bob Parke during the mid-80s as I recall. They named it as they felt it is extremely cold hardy and almost bullet proof in disease resistance. My own experience tells me they were right on these attributes. I virtually never spray it and it does not generally suffer cold injury, even here in Minnesota. However, the grape is low in vigor and takes a year or even two longer to become established and start to bear adequately. Once it is 5-6 years old the vigor element, while still only moderately vigorous growing, is less of a problem. It is not heavy bearing either and it difficult to get over 10 lbs./vine. The clusters tend to be smallish and quite tight. Bunch rot has not been a problem with it.

It ripens to a bright, light green color, in mid-Sept. that becomes yellow and is quite handsome. It makes a delicious and popular eating grape and we sell it as a table grape at the local farmers market. If you can find people who can past this American predjudice for seedlessness they are well liked with a delicious fresh grape flavor.

The wine has been extremely light. Some call it subtle others call it tasteless (I think an overstatement). Plocher and Parke named it as a blending grape to be blended with Prairie Star which they named at the same time. Together Louise adds a nice honey bouquet and flowery aroma giving a subtle honey after taste as well to the more straight forward Prairie Star. One grower who I respect says he has found that leaving Louise on the vine to ripen as a late harvest grape says it develops more body and flavor when done so. Even so the grape usually does not ripen to over 18-20% sugar but we are beginning to see that because of its hardiness, disease resistance and reliability it has a place in Minnesota’s wine culture.

How it might perform in other climates would be of interest to see.


John Marshall


Mark yields do not have to be low with Louise. I don’t have multiple year yield records on this computer for the Willsboro Baker Farm trial but I always found the crops to be quite similar year to year. I do have records right now for 2010 and it shows the average yield as 8.9 Tons/acre. The yields ranged from 7.85 to 9.67 T/A for the vines. The soil at the site is a well drained loamy soil with adequate rainfall and ~2600 GDD. I will try to get several years yield data tomorrow from Willsboro.

Here at home they did establish slower than the LaCrescent but have really nice large clusters. We space them at 6 to 7 feet and they fill the canopy well.

Richard Lamoy

Hid-in-Pines Vineyard


Just adding to what Rick and John have said.

I have it on a lower vigor sandy site in Northern Wisconsin. It took forever (5-6 years) to reach the top wire. It very slowly filling out. So I would suggest a 4’ in row spacing on this vine in a lower vigor site, and maybe 6’ in higher vigor. With the lower vigor the canopy is very open due to short and sparse cane growth. Yields will probably always be marginal for commercial production.

Even in warmer areas it is not a high brix grapes; 20 brix is about as high as it will go. I usually find it at 18-19 when it ripens here. That is another reason to blend it. If it does get fully ripe (>19) it can make a very nice stand alone wine. Acid levels are pretty low, so the chemistry is balanced. Fruit ripens slowly after reaching 19 brix, but the berries hold up very well on the vine. It ripens fruit early, and has excellent wood ripening characteristics. Most growers find it very hardy, but I did hear from a grower in ND that saw extensive dieback last winter on Louise and is removing the vines.

Given that yields will probably always be marginal for commercial production, I would only recommend it as a small portion of a commercial operation, where it gives some complexity to blends and will provide a low, but reliably ripening crop.

Mark Hart
Bayfield WI USA


Here is the yield data from the Willsboro Baker Farm for the past 4 years. Attached is more detailed data on the variety.

Please take this with a grain of salt. I believe 2013 yields were lower due to the some experimentation with bud thinning, which I was not involved in. This year the planting could have used quite a bit more pruning and vine thinning, which may partially explain the higher yields.

Yield is on a per vine basis, and yield per acre is based on 550 vines/A, as the spacing at the Willsboro Farm is 8×10′.

Louise Swenson
Year #clusters yield/vine (kg) clus wt (g) yield (t/A) @550 vines/A
2014 158.3 15.0 98.7 9.1
2013 75.1 5.6 73.9 3.4
2012 91.3 12.4 137.5 7.5
2011 71.2 10.1 147.3 6.1
Average 99.0 10.8 114.3 6.5

Anna Wallis
Cornell Extension


Hi Everyone,

I’ll add my experiences, but I hope that Ethan from Shelburne, might chime in too. He is one of the 3 bigger growers of Louise in VT and each of them has yet to share their experiences.

I’ll start by saying that while I know those yields as Willsboro are accurate, I have never seen close to 9 tons per acre commercially. Those numbers are for only a few vines and maybe should not be extrapolated over an acre. I have seen 4-5 tons per acre for several years in a row now at a couple of VT operations. This is where I think Louise’s sweet spot is for consistent good crops. On the right ground with the right viticulture, this is a commercially viable white wine variety. I have been selling this variety to growers around the US for the last 12 years and have heard quite a few other reports too of difficulty establishing it or growing it on.

I think that Alain’s comment on rain is critical. Whether it is more rain in the east, choice of heavier, wetter ground to plant it on, or regular irrigation, Louise only performs well and establishes quickly when there is a lot of water ALL season long. It has a way of simply shutting down when it dries out too far and never begins to grow again. This is why I largely encourage growers to put this variety on the heavier soil in their vineyard. I also agree with Mark that it should not be planted much more than 5′ apart in the rows, with plantings on sand being as tight as 3′-4′. Louise is the lowest vigor vine that I grow. But to me, that is one of its best characteristics. Many northern growers fight excessive vigor, but Louise seems to have a perfect canopy when grown on TWC. Not really any need to shoot thin, but sometimes cluster thinning is needed where 3 clusters are on a shoot. I feel that it does take less input to grow than say Marquette which takes shoot thinning, leaf removal, shoot placement, etc. I do keep it sprayed at my place. Where it has gone with less fungicide in the east, I have seen some pretty nasty Anthracnose infections, and of course black rot too. NEVER SPRAY SULFUR ON LOUISE. It, as well as many other Swenson varieties, are sensitive to this chemical.

It is one of the earlier ripening grapes. I am not a winemaker, but I will say that there is some really interesting work being done now to make Louise into a Sauv blanc style with a lot of success. Sure, it will always be light in body, we need to figure out the best way to deal with this. Aromatically, it can be great with honey, tangerine, and floral notes. Skin contact?

At this moment in northern grape growing, I feel that Louise Swenson has a solid position as a dry white wine grape as we have few other options in this category. I do know that a couple of breeding programs are also working on a lower acid white, and hopefully it has some body to it. This is a really important wine category in the tasting room.

On a last note, I would like to put out the notion that not all grape varieties can be grown identically. Maybe it would great if everything grew like Frontenac, but that is not our reality. Some growers have a tough time with Louise Swenson and rip it out. Some growers have a tough time with La Crescent and rip it out. It does not mean that these varieties are not worth growing commercially. It also does not mean that some growers are very successful with them. To me, it means that we have to up our game as grape growers and identify the unique characteristics of each variety and then apply the most appropriate viticulture to them. I’ll add more if it comes to me, but that’s it for now. Have a great weekend everyone.

Andy Farmer
Northeastern Vine Supply, Inc.


Hi Folks: My experience with Louise has been very positive — closer to the reports from Willsboro than from the midwest. On a commercial scale planting, we’re averaging 4-5 tons per acre. We have a very rich, fertile soil — which is a curse when trying to control excess vigor on Marquette and Lacrescent, but which is a blessing when growing Louise. I made a new planting in 2012 of Louise, and I’d say that 70% of the plants have filled their trellis in two years and will bear a light crop next year. (Great nursery stock from NE Vine Supply helps, too.) Louise will struggle up to 20 brix here, but I prefer the wine when picked early, around 17.5, and chaptalized up to 21 or so. Our 2013 “Black Sparrow” wine is my favorite dry white we’ve ever made ( and won double gold at ICCWC). It’s about 55% Louise, the balance is a mix of Prairie Star, Adalmiina (ES 6-16-30), and Frontenac Gris (10%). I wish I could turn back the clock and have planted a lot more Louise years ago.

Our Louise vines are spaced 7 x 9, which works well on my rich soil. A closer spacing is probably a good idea on average soil. We use a top wire cordon.  Also, if we have a nice cane in a good position we like to replace the cordons fairly regularly. If not, the spurs tend to get too long

By the way, I think that Adamiina is the star of this group when it comes to wine quality — although is does seem lighter bearing than Louise, and quite susceptible to late summer fruit rots.

Chris Granstrom
Lincoln Peak