Frontenac
Frontenac is a vigorous variety and usually becomes established very quickly. Typical spacing on fertile soils would be about 8' between vines. Best results to date have been obtained training Frontenac to an upper cordon system with canes. Frontenac produces only a moderate number of tendrils, which facilitates vine management.
In Minnesota, Frontenac ripens in late-midseason, about 10 days after Foch. It is important to let the fruit hang long enough to fully mature in order to reduce the acidity to workable levels. This becomes less of a problem when Frontenac is grown further south under warmer conditions. Fortunately, the pH does not often rise to dangerous levels. Frontenac is a good sugar producer with 24-25 brix not uncommon.

Marquette
Marquette is a cousin of Frontenac and grandson of Pinot noir. It originated from a cross of MN 1094, a complex hybrid of V. riparia, V. vinifera, and other Vitis species, with Ravat 262. Viticulturally, Marquette is outstanding. Resistance to downy mildew, powdery mildew, and black rot has been very good. Its open, orderly growth habit makes vine canopy management efficient.

La Crescent
La Crescent is a grape variety to be used primarily for white wine production. The plant of La Crescent is moderately vigorous and very winter hardy. The vines are moderately resistant to phenoxy herbicide injury and moderately susceptible to foliar phylloxera damage. The diseases downy mildew and black rot have been observed on the leaves but not on the fruit. The vines set a light to moderate crop load that varies from year to year. The fruit are borne on a loose, medium sized cluster. The berries are small to medium sized and amber with a waxy bloom at maturity. The fruit at harvest is usually relatively high in sugar and moderate too high in acidity.

Frontenac Gris
Frontenac gris, the white wine version of Frontenac, started as a single bud mutation yielding gray (thus named gris) fruit and amber-colored juice. The vine exhibits the same optimum growth characteristics as Frontenac, and requires the same cultural practices. Arching canes and minimal tendrils provide easy training and pruning to simplify vine management. In Minnesota, Frontenac and Frontenac gris ripen in late mid-season, and are good sugar producers with 24-25°Brix not uncommon.

Prairie Star
This is a mid-season white wine grape from Elmer Swenson. It is usually harvested at 20 to 22 Brix during the third week in September in the St. Paul area. Prairie Star has long, slightly loose clusters that, on heavy soils or on grafted vines, can average 177 g (range 120-240 g). On lighter or less fertile soils, cluster size will be closer to the lower end of this range and production will be less. Berries are small-medium, averaging 2.5 g. The fruit matures to excellent sugar and acidity for white winemaking. The typical wine from Prairie Star is neutral, but not foxy. It has a fullness in the mouth and finish that is uncommon among our hybrid grape varieties. In some years, wines from Prairie Star develop a delicate floral nose that allow them to stand as single variety wines. In most years, however, Prairie Star is best used as a blending component to add body and finish to thinner white wines.