Grape variety identification
Terminology note: cultivar or variety are used in viticulture
Hobby grape growers/home garden
There are thousands of grapevine cultivars grown worldwide, and it is difficult to identify grapevines based on photos or plant samples submitted to or dropped off at an Extension office. If the plant is diseased or unhealthy, it makes it even more difficult for visual identification. If you want to identify the variety of a grapevine in your home garden, you can use the resources listed below for commercial growers. However, it is difficult to narrow down your choice of cultivars to begin searching online databases. Therefore, we suggest that you begin with the most common grape varieties sold to homeowners. You can search garden centers and seed and plant catalogs online to determine what is distributed to homeowners. Below are additional resources that provide details on such varieties.
- Many grapes for the home garden are American grape varieties, as they are more disease resistant. These may be used for table grapes (fresh eating), juice (or wine), or jams/jellies. Some are crosses between American Vitis species and European grape species (Vitis vinifera). To learn more about different wine, juice and table grape varieties, check out the following online resources for descriptions and photos:
- Keep in mind that some cultivars that are available now were not available decades ago. Therefore, if you suspect that your grapevine is decades old, it may be one of the more traditional cultivars available through garden centers.
- If you want help identifying your grapevine, contact your county Extension office for assistance. Specifically inquire with the Master Gardener Help Desk, as they may be able to further assist in cultivar identification based on their experience and other local resources. However, make sure that you have clear photos that identify the plant parts (see Ampelography below). Make sure you have photos of your plant with ripe, disease-free fruit. Having diseased or unhealthy plant tissue makes it difficult for cultivar identification. Also, know what color it is when ripe, whether it has seeds or is seedless, and some other characteristics of the berry and flesh/skin texture. A Master Gardener or local Extension office staff will not be able to definitively identify what cultivar you have growing in your garden/landscape due to concerns listed above, but they may give you some general idea of what type of grape it may be.
If you do not have records of the plant material planted in your vineyards, there two ways to determine the cultivar and rootstock. However, the methods have different levels of accuracy.
- Ampelography – You can use physical characteristics of the shoot tips, leaves, and fruit to identify the grape cultivar. This is a complicated process, and the details provided in the following guide provide details on this complexity: official grape identification guide. The Vitis International Variety Catalogue can be used to search cultivars and rootstocks for images of shoot tips, leaves and fruit. Use the database search feature. This is helpful in determining the variety but is not completely definitive.
- DNA testing -- If you want to be certain about the cultivar or rootstock identification, send leaf samples for DNA testing at Foundation Plant Services. The service comes at a cost, but is the only way to specifically determine the cultivar. However, be aware that DNA testing cannot identify a cultivar to the clone level at this time. For rootstocks, you will need to use leaf tissue from suckers growing from below the graft union for identification.