Notes on the soil

The vineyard is on a river bank.  Next to the river, the soil is sandy.  About 300 feet from the river bank is a limestone outcrop.  As you get closer to the limestone, the soil increases in clay content and limestone cobbles grow more common.  Near the outcrop, it is a clay loam with many cobbles, some very large.  I started planting about 60 feet from the outcrop, and have added rows to fill in the area up to the outcrop. 

This year, I'm starting a new set of rows adjacent to the river bank, where the soil is very sandy.   The Pierce's Disease pressure should be higher, too.  The sharpshooters that carry the bacteria need the active growth near the water's edge. The higher PD pressure will help the selection process.

The pH is around 8.0.

I've been planting seedlings from a single cross in different soils to see if they have preferences.  Some crosses clearly prefer specific soil types, but my impressions are entirely anecdotal.  The wild cinereas like the limestone cobbles.  The wild mustangs like the sand.  Rupestris is pretty vigorous in the loamy area.  I'll plant some new largely rupestris seedlings up the near the limestone this spring.

Crosses with lots of aestivalis or labrusca crosses don't grow very well anywhere in the vineyard.  I don't know if it is the heat, the Pierce's Disease or something else.