Athena Lamberis

For the past years, we have had powdery mildew on our fruit grapes and rust on the leaves by July. Most of our neighbours tell us to do a sulfur fungicide...
We thought our pruning in autumn and spring helped the solution when the new grapes arrived but by July, the mildew returned. Perhaps from June rains.

Should we be pruning in May to thin out the growth?

The grape is in soil with a rosemary plant and yarrow and wild strawberry. It gets beautiful sunlight all day long.

We are really trying to preserve the beauty and production of these old vines with a permaculture approach, so asking advice on what more we can try. Have read this and want to reduce chemical residues as the grapes are in front of our house and under our outside dinner table.

https://www.novobac.com/powdery-mildew-of-grapes/ Any seasonal advice on how to prevent and resources to read will be a great help for us to come up with a plan.
Thank you Permies!

This is the land infront of the drop, and you can see the house foundation in the distance (to the East that leads to a road, but there is a ravine to the west, so no need for a road . . . so we could certainly terrace so we don't risk loosing these trees.  

Thank you Nick,

We suspect it to be rainfall during the winters. We don't have much info as the house grounds were not occupied for many years. There is an old well above and a 40 degree slope of thickforest above.  There is a slope that faces more East which has been overtaken by Spanish broom which helped with some of the minor mudslides in previous years, we were told. I would like to see what would take root, but perhaps I need to terrace it a bit as it's almost a 90 degree drop.

Hello from Greece, Arcadia - Zone 8b.

We have moved to the beautiful Skiritida Forest, rich with sweet chesnuts, pine, oaks, and cedar, and firs.  50 metres from our house is a North-facing slope that is steep and showing bad signs of erosion.  Some neighbours suggest chopping the beautiful old pines on the edge and I am resisting. Any feedback to save this magic ledge of the food forest and help restore the eroding land.  We are open to all ideas. Pictures attached.