I am planning to grow grapes on the roof of my house. I am living in rainy environment and also with cloudy weather. Is it possible to cultivate grape in such kind of environment?
My grapes appear to be thriving and we've had more rain than 90 year old men can remember ever seeing. We're averaging 10 inches per month and in July we received 15 inches. My Pink Reliance and Concords are packed with grapes.
The cloudy weather may affect the sweetness of the grapes since sunlight is needed to make sugars.
But to ask is it possible to grow them, yes, its possible.
With increased rainfall its important to monitor calcium levels in the soil since rain heavily leaches calcium and grapes do appreciate a fair amount of calcium. I fertilize with calcium nitrate.
Bordeaux, France is surprisingly rainy but produces excellent wines. Though, their 'better' year's are often in times of lower than average rainfall.
Grapes do not require much in the way of mineral nutrition, with the exception of some initial nitrogen amendments, but this really is dependent upon your soil type.