At the wineries of Bordeaux you will find roses at the end of the vineyard rows. I always thought they were planted to make the vineyards look more beautiful. Apparently not. These roses are like guardian angels to the grape vines. Making sure that the vines are taken care of. Apparently both the roses and the grapes are sensitive to the same mildew that kills these plants. So if anything happens to these roses, it would be indicative of something wrong in the vineyards and serve as an early warning to the wine growers.
The vineyards at Chateau Villamaurine, St. Emillion