Louise Swenson Grape Vine

Louise Swenson is consistently cold hardy to approximately -40°F. Vines exhibit moderate vigor with a tidy, well-structured growth habit and rarely require shoot thinning. Bud break occurs relatively late in spring, contributing to excellent frost avoidance, and the variety shows very good overall disease resistance. It performs best on heavier soils or where irrigation is readily available.

Yields are reliable, producing medium-sized clusters at approximately 3–4 tons per acre. Sugar accumulation is modest, typically reaching 18–20° Brix, while acidity remains naturally low—making Louise Swenson an excellent candidate for dry white wine production. Wines can be exceptional, offering refined aromas of flowers, honey, and tangerine. If fruit is left to over-ripen, slight labrusca character may develop. Wines are generally light-bodied and benefit from small blending additions of Prairie Star or Frontenac Blanc for added structure and weight. The variety is sulfur sensitive.

Clusters are small to medium in size, bearing round, medium-sized berries that turn a yellow-gold color at maturity. Berries measure approximately 1 cm and contain 3–5 small seeds. Fruit is suitable for fresh consumption as well as preserves, juice, and wine. Ripening typically occurs from late August through early September, with fruit keeping up to one week under refrigeration. Vines begin bearing fruit two to three years after planting.

Louise Swenson is a climbing vine with a fast growth rate of 2–5 feet per year and can reach 20–30 feet when provided a suitable support structure. Recommended spacing is 6–8 feet apart in sheltered planting locations. The variety is well adapted to USDA Zone 3a and requires at least six hours of sunlight daily to ensure healthy foliage and fruit development. Large, three-lobed, serrated leaves provide a textured canopy and turn yellow in autumn. Small white flowers bloom in panicles in June. While self-fertile, yields may increase when a pollinator is planted within 200 feet. Powdery mildew susceptibility increases in shaded sites or during periods of high humidity.

Named for the wife of renowned Upper Midwest grape breeder Elmer Swenson (1913–2004), Louise Swenson descends from a cross of Kay Gray and Swenson hybrid ES 2-3-17, with Seyval Blanc in its lineage and more distant ties to Cayuga White and Brianna. Plantings of Louise Swenson have expanded rapidly in recent years, and its popularity continues to grow.

In the vineyard, Louise Swenson earns high regard for its exceptional cold tolerance and resilience under challenging growing conditions. Though clusters are small and yields modest, the resulting wines often prove that quality outweighs quantity. Aromatically expressive, wines display a charming range of floral notes layered with pear fruit, subtle minerality, and a signature honeyed nuance. Typically harvested around 18° Brix, the variety retains energy and balance, making it well suited for both varietal bottlings and blending. Louise Swenson has also shown promise in sparkling wine trials, where its orchard fruit aromatics and textured elegance truly shine.

USDA Zone: 3-9

Ripening Dates: Late September

Sun: Full Sun

Mature Height: 12-15' and higher with proper support

Mature Spread: upwards of 15'

Support Needed

Self Fertile

Due to individual state restrictions, we are unable to ship grape vines to customers in Oregon, Washington, and California.

Ships Spring 2026