#1 Grapevines Dormant Rootings Dormant Benchgrafts Green Growing Benchgrafts #2 Grapevines, Jumbos, & Substandards For More Information
Jim Wolpert and Andy Walker, University of California, Davis
Adapted from a three-part article that appeared in American Vineyard magazine, April, May, and June, 1996.
At this time, there are no national standards for grapevine materials. In some states, such as California, nurseries voluntarily use the following grapevine grading standards: #1, “Jumbo,” #2, and Substandard.
#1 Grapevines
To be considered a “#1 Grapevine,” a plant should have the following attributes for dormant rootings, dormant benchgrafts, and green-growing benchgrafts.
Dormant Rootings
- Length: 14 inches.
- Caliper: 5/16-inch or more.
- Nodes: Four or more, counting the top and basal nodes; some rootstocks (especially SO4, 5C, 5BB) have a genetic tendency to produce cuttings with longer internodes and may have cuttings with three nodes.
- Top growth: At least 8 inches of mature growth, prior to trimming.
- Root growth: At least three roots with diameter at least 1/32-inch originating from the basal area of the cutting and distributed radially around the base.
- Overall appearance: Rootings should be reasonably straight, round (not flattened in cross-section), free from physical damage and obvious diseases (e.g., crown gall or internal necrosis).
Dormant Benchgrafts
- Length: 14 inches (12- to 13-inch rootstock and 1- to 2-inch scion).
- Caliper of rootstock: 5/16-inch or more.
- Nodes: Four or more, counting the top and basal nodes; some rootstocks (especially SO4, 5C, 5BB) have a genetic tendency to produce cuttings with longer internodes and may produce 14 inch cuttings with only three nodes.
- Top growth: At least 8 inches of mature growth, prior to trimming and scion caliper should be at least 5/32-inch.
- Root growth: At least three roots with diameter of at least 1/32-inch originating from the basal area of the cutting and distributed radially around the base.
- Graft union: Well healed and able to withstand modest lateral pressure (the “thumb test”).
- Overall appearance: Rootings should be reasonably straight, relatively round (not flattened in cross section), free from physical damage and obvious diseases (e.g., crown gall or internal necrosis).
Green Growing Benchgrafts
- Length: 8 inches to 10 inches of wood above the soil line (6 inches to 8 inches of rootstock, 1- to 2-inch scion).
- Caliper of rootstock: 1/4-inch.
- Top growth: A well-developed shoot, at least 6 inches long with active new growth.
- Roots: Roots should be visible at the bottom of the container and appear to be actively growing (pale white with no discoloration).
- Graft union: Should appear to be reasonably well healed around the circumference of the union without excessive callus growth. Graft unions are only a few months old and, of course, cannot be expected to be as fully healed as dormant benchgrafts. The union will be covered with wax, making inspection more difficult.
- Overall appearance: The rootstock portion should be reasonably straight, round, not flattened, free from physical damage and obvious diseases (e.g., crown gall or internal necrosis). Some basal leaf desiccation can be expected but should not be extensive. Active top growth is a good indication of graft union healing and root development.
#2 Grapevines
To be considered a “#2 Grapevine,” vines should have between 4 and 8 inches of top growth. Root development will be less than #1 in size and number of roots, and roots may not be uniformly spaced around the base of the cutting. Some #2 rootings may be 10 inches or shorter in length, but growers should not accept this material as it is too short to provide the recommended 4-inch distance of the graft union above the soil line and still have the root ball 8 inches below the soil line.
Jumbo Grapevines
To be considered a “Jumbo Grapevine” a vine will likely exceed #1 Grapevines in several categories including caliper of rootstock, top growth, and number and size of roots.
Substandard Grapevines
Substandard Grapevines have some root and top growth but do not meet the minimum standards for #2 grapevines.
Recommended Resources
Ordering Grapevine Cuttings and Plants from Nurseries
Common Miscommunication Problems between Grape Growers and Nursery Plant Suppliers
Reviewed by Eric Stafne, Mississippi State University
and Sara Spayd, North Carolina State University