Roses and Grapevines

I saw this in Tuscany on my trip there, and found this so interesting.

Vineyards historically plant roses at the end of grape rows to act as an early warning system for diseases like powdery mildew and downy mildew. Because roses are more sensitive to these fungi than grapes, the roses show signs of infection first, giving winemakers time to treat the vines before the crop is ruined. 

• Early Detection System: Roses and grapevines share similar susceptibility to fungal diseases. If mildew or black spots appear on the roses, it acts as a signal that the environmental conditions are also ideal for the same diseases to attack the, more valuable, grapevines.

• Historical Pest Management: Before modern pesticides, roses would show signs of infestation by insects like the glassy-winged sharpshooter before the vines did, allowing for faster intervention.

• Practical Navigation (Historical): In the era of horse-drawn plows, the thorny rose bushes served as a barrier that forced horses to make wide turns, preventing them from damaging the vines at the end of the row.

• Visual Aesthetics & Identification: Roses add beauty to the vineyard, and in some cases, different colored roses are used to identify the grape varieties planted in that specific row. 

While modern technology has lessened the need for this natural warning system, many vineyards continue the practice as a tradition and for integrated pest management.