Can Organic Grapes Grow in Pennsylvania?

First year results are promising in trial using Verona cultivar

by Linda Jones McKee
wine  grapevine pennsylvania verona organic growing experiment
Researcher Chelsy Villarroel examines young Verona grapevines as part of an experiment at Mountain View Vineyard near Stroudsburg, Pa.

Stroudsburg, Pa.—When Randy and Linda Rice, owners of Mountain View Vineyard, expanded their vineyards onto a 100-acre farm southwest of Stroudsburg in northeastern Pennsylvania, they wanted to be as sustainable as possible. In 2016, they applied for a Sustainable Agriculture Research and Education grant, and the U.S. Department of Agriculture selected Mountain View Vineyard to be part of an experiment to see if farmers could grow high-quality wine grapes organically in Pennsylvania.

With technical advice from Bryan Hed, research technologist at Penn State’s Lake Erie Grape Research and Extension Center in Erie, Pa., and consultant for the organic project, this April the Rices planted 3.5 acres with 2,000 Verona vines, half grown organically and half using conventional sprays. On Nov.  22, the winery held an organic farming field day to present the results from their first year of attempting to grow Verona organically. Initial results are promising for the grape variety, but the second and third year of trials will be important.

Why grow Verona organically?
While southeastern Pennsylvania has a moderate climate with temperatures that rarely drop below 0° F or go above 95° F, the weather is often wet and the humidity is high. Because the Pocono mountains in northeastern Pennsylvania are higher in elevation, the temperatures are cooler, but it is still humid and wet. As a consequence, grapevines are prone to downy mildew, powdery mildew, black rot and botrytis, among other diseases.

Because of the climate, the Rices have chosen to plant only hybrid grapes, including cold-climate varieties Noiret, Petite Pearl, Arandell, Chambourcin and Traminette, rather than vinifera grapes such as Cabernet Sauvignon, Chardonnay or Cabernet Franc that can be more difficult to grow. The Rices selected Verona because it is a cold-hardy grape that produces vinifera-like wines with a good balance of acid, tannin and alcohol.

Tom Plocher, a grape breeder based in Hugo, Minn., made the cross in 1997 that became Verona between Troubador (a cross by David Macgregor of Riparia 89 x St. Croix) and E.S. 5-4-16 (one of Elmer Swenson’s unnamed varieties). Plocher told Wines & Vines that Verona isn’t very prone to disease, stating, “I’ve never seen black rot on the berries and only on a few leaves.” While he employs a minimal spray program on his vines, Plocher does occasionally use copper to control downy mildew. In 2016, his location northeast of Minneapolis received a record amount of rainfall: 16 inches between mid-July and mid-August. “Verona hung in there through September,” he said. “I didn’t see any rots on it, even though it has pretty tight bunches and big berries.”

In addition to good winter hardiness, Verona has several other advantages. It has a late bud break in the spring as well as good production on secondary buds. It also has some resistance to fall frost, which allows the fruit to hang and ripen later into the fall. Grape parameters are 22°-24° Brix, pH of 3.25 and total acidity of less than 1.0 gram per liter. In tests at North Dakota State University in 2012, ripe berries from Verona vines ranked No. 1 in tannin content out of 34 skin samples from northern grape varieties, with a good ratio of tannin/total polyphenols.

Wines made from Verona grapes have deep red color and abundant soft tannins in the mid-palate and finish. According to Plocher, the wine’s aroma “is complex; a characteristic raspberry aroma is dominant, changing to blackberry as it ages in the bottle.” There are dark chocolate flavors along with raspberry, with an excellent balance and finish, all in a “style that is a bit reminiscent of a Tuscan red wine.”

The experiment
Back at the Rices, two plots were planted, each with 15 rows of about 66 plants per row. Three sprays were applied to each plot during the growing season and were made pre-bloom and post-bloom in 30 gallons of water per acre. The control plot was sprayed three times with a mancozeb fungicide, Roper Range Shield (at 2 pounds per acre), while the organic test block received Champ Formula 2 Flowable (copper hydroxide) at 2 pints per acre.

Sampling of leaves for disease assessment began July 21 and continued until Oct. 6. On each of the eight sampling dates, 300 leaves from each block were examined for the presence of disease, and symptoms were quantified as incidence (percent leaves with disease) and severity (percent area diseased) using the Barratt-Horsfall scale, according to Hed. Severity data were converted to percentage area infected using Elanco conversion tables. Leaves also were checked for damage by copper fungicide.

The results
Black rot was first observed July 21. One leaf in the organic block had a single small lesion on that date, but black rot remained at very low levels throughout the summer. The control block remained free of black rot throughout the growing season. Downy mildew was not seen until Sept. 1, when a single lesion on each of two leaves was found in the conventionally treated block. The organic block was completely free of downy mildew throughout the rating period.

These results occurred in conditions that were less than ideal for growing any kind of grapes. The region had a cool, wet summer until after Labor Day, and even experienced growers using multiple sprays had trouble keeping downy mildew under control.

“We’re really pleased,” Randy Rice said. “The first year doesn’t tell us as much as the second or third year, when the fruit sets, but we’re excited about Verona.”

Hed noted that it is very early to tell how Verona will do organically. “This is an isolated site, with some grapes that are two or three years old. There’s some black rot in other blocks that are 100 to 200 yards away. Whatever was seen in the Verona this year may have come with the vines, especially the black rot. It’s too early to draw solid conclusions, but it is encouraging. If Verona is resistant to black rot, that’s going to be huge.”


Posted on 12.17.2017 - 16:01:05 PST

What varieties were you growing, and is the site near/bordered by trees? Is there good air drainage? Did you use dormant sprays to reduce spores? Spray borders and headlands?

Jim Moss
Apical Vines Nursery/Bright Light Vineyard


Posted on 12.11.2017 - 08:50:17 PST
Our original Vermont vineyard planting was certified organic. In the first few years managing with just copper and sulfur appeared to be sufficient. But as the vines matured just about every common vine disease found our vines and the health of the vines declined year after year. We abandoned organic certification and the health of the vines recovered. Still, organic growing is desirable and we may try again with a small section of our vines.
Kenneth Albert