---

John Marshall, owner of the Great River Vineyard and Nursery in Lake City, will be teaching a class on growing grapes in Minnesota at the Master Gardener Gardening Bonanza March 6. He is also the secretary of the Minnesota Grape Growers Association. John and his wife, Barb, established their vineyard in 1988. He’ll share tips from their 25 years experience on site selection, planting, trellising, weed control, disease identification, spraying and cold hardy varieties that you can grow.

I do have some grape plants that were dropped off for me one Father’s Day. Last fall we harvested our first grapes and it was pure luck rather than having a green thumb. I will be very busy during Bonanza at the main booth taking orders for strawberry, raspberry, grape and blueberry plants. However, I plan on attending part of John’s presentation as I know very little about grapes.

Most of this article is taken from articles written by Doug Falk, Extension Educator, Ramsey County. Doug claims that since Minnesotans love a challenge it may explain why they want to grow grapes. To be successful you must provide a warm sunny site and a structure for the vines to rest on.

Grapes require full sun and serious warmth to grow and ripen properly. A north facing slope or a spot near the oak tree that receives half-day sun will not work for growing grapes. They want the sunniest, warmest spot you can give them. Plant them in full sun on a south, southeast or southwest facing slope, or on the south side of a building or windbreak. They do best in sandy soil because it warms up more quickly in the spring than other types of soils. Grapes will not tolerate poorly draining soils so if that is what you have, you need to improve drainage, create a raised bed or select a different site.

Herbicides are usually not a concern for the average gardener unless the site is close to an area where they spray for weeds. Grapes are extremely sensitive to various herbicides. Even the vapors rising from a nearby application on a warm, still day can cause harm. Therefore, think about not only your own herbicide usage, but also that of your neighbor on the farm across the road. Roadsides, small grain fields and lawns may also receive frequent treatments. If anyone nearby uses 2,4-D or other broadleaf herbicide, you may want to consider growing a fruit crop other than grapes.

Grapes must be kept off the ground. You don’t have to build a trellis as many grapevines have thrived on a standard fence. The main idea is that a suitable structure is needed to support their growth.

Prevention of grape disease starts by planting hardy varieties or suitable sites. Properly water, fertilize and prune plants to maintain vigor. Controlling weeds can reduce the number of infections by lowering the humidity around the plants. Clean up all plant material, including fruit, at the end of the growing season to reduce the number of infections the following year. Fungicides may be used for preventative treatment or to prevent the spread of the disease to healthy plants. Captan and Bordeaux mixture are available to manage black rot, downy mildew and powdery mildew.

As I wrote in the beginning of this article, I need to hear some of John Marshall’s presentation. My own interest is on the proper pruning of grapes. I do know that they need to be pruned in late winter or very early spring, much like apple trees.

We will be taking orders for four varieties of grapes at our Bonanza. St. Croix red is a red grape that is hardy to -32 degrees. It has good resistance to powdery mildew and black rot. It ripens mid-season and makes great wine or is good as a table grape.

Swenson Red is a red to blue colored seeded table grape. It is above average vigor as it’s hardy to -30 degrees. This grape has a strawberry-like flavor and is excellent table grape.

Frontenac Red is a wine grape with fair resistance to powdery mildew and is immune to downy mildew. Its wine has a cherry aroma and is the most widely planted wine grape in Minnesota. It is hardy to -35 degrees.

Edelweiss White is a seeded table, wine and juice grape. It is hardy to 30 degrees and has excellent disease resistance. This grape ripens early in the season.

+++++

Brochures are available for Bonanza 2004 “Garden Fever,” which will be held at Maranatha Church, in Forest Lake, March 6. Call or email to receive a brochure or if you are interested in being a vendor, 651-237-3080 or [email protected]. Forms are also now available to preorder bare root strawberry, raspberry, blueberry and grape plants. Many of these are cultivars developed at the University of Minnesota and used by commercial growers, but hard to find for home use. You can view the brochure and order form on the web at:

http://www.extension.umn.edu/county/Chisago/news/brochure2004%20final.pdf

We regret to say there will not be plant clinics at our office this year. Many of you have stopped in or called on Monday nights of during office hours for help with your questions. The office space we are in at the Green Acres Care Facility is less than 25% the size of our old office by the Tanger Mall. There simply isn’t space available to have volunteers come in to work or for the public to be able to drop things off. Also, the paid Horticultural position was cut to 10 hours per week. There will, however, still be Master Gardeners at the Lindstrom farmer’s market on Saturday mornings and we are looking to have other locations where samples can be dropped off. Please be patient as we continue to work through these changes.

---