Grapevine Root Systems
Grapevines tend to have deeper and less dense root systems than many other plants, so it's important to plant grapes in deep soils whenever possible. The health of a grapevine plant is often an indicator of its root growth. Grapevine root systems also vary somewhat, depending on the variety of grape.
About 60 percent of grapevine roots sit in the top 24 inches of soil, but many of the plant roots grow much deeper. Grape roots can grow more 20 feet deep. You can dig down into the soil while grapevines are dormant to check the vigor of the roots and the quality of the soil, notes Australian Cooperative Research Centre for Viticulture.
Grapevine roots are generally less dense and spread out than many other plants, but they can still spread a great distance from the main vine trunk. University of California, Davis, Department of Viticulture & Enology notes some studies suggest that the roots can spread as far as 33 feet. Most of the root density is closer to the trunk, but a significant amount is sometimes more than three feet away from the trunk. About 15 percent of root biomass is 47 to 59 inches from the trunk.
Effects of Soil Quality
Soil texture and pH affect the development of grapevine root systems. As soil acidity, density and poor water movement increase, root vigor decreases. Compacted and shallow soils lead to roots that grow out horizontally instead of deeply. Grapevines in soils with coarse textures have less dense roots than those in fine-textured soils. Soils with layered profile changes, such as layers containing lots of stones or clay layers, have inconsistent root distribution.
Effects of Irrigation
Available moisture in the soil encourages the growth of root systems. For table grapes, you want the vines to grow as vigorously as possible. On the other hand, winemakers often want the vines to struggle a bit. A struggling plant will produce fewer grapes with a stronger flavor and more complexity, which produces high-quality wine. One way to increase grape production is to weed the area around the grapes so other plants do not compete with grape roots for soil moisture. Winemakers sometimes intentionally do the opposite and plant a grass covering to reduce the amount of moisture in the topsoil.
Different varieties of grapes have naturally different root growth patterns. Riverbark grape (Vitis riparia) roots grow more vertically, while sand grape (Vitis rupestris) roots have more lateral growth. Hybrid varieties have an in-between growth pattern.
- University of California, Davis, Department of Viticulture & Enology: Grapevine Rooting Patterns: A Comprehensive Analysis and Review
- Cooperative Research Centre for Viticulture: Vineyard Activities 9: Examining Grapevine Root Systems
- American Society for Horticultural Science: Preliminary Report of the Root Systems of Grape Varieties
Lisa Chinn developed her research skills while working at a research university library. She writes for numerous publications, specializing in gardening, home care, wellness, copywriting, style and travel. Chinn also designs marketing materials, holds a Bachelor of Science in psychology and is working toward a PhD in cognitive neuroscience.