A strong positive correlation means that as one variable increases so does the other and that they do so in a linear relationship. So what this means is that “as the rainfall increases, the number of peaches a tree produces increases.”
It does not mean that the rainfall causes the tree to produce more peaches. The correlation only establishes that the two variables are related in that one increases as the other does. It is NOT the case that this means for sure one causes the other. We cannot assume causality when using a correlation.
It might be that the rain causes more peaches to grown or it might be that some other factor or combination of factors causes the growth. We just do not know.