Hi Charles,
Interesting you should mention possible effect of trees. My garden is long and narrow and my neighbours’ gardens running the length of my garden on both sides each contain several large trees including 60ft eucalyptus, even taller sycamore, numerous leylandii-type evergreen trees also fully grown. Our gardens are all the same size(10mtr x 35mtr).
Because of the position and influence of the eucalyptus I have placed my wooden-sided, raised beds in the middle section of my garden and although this particular tree doesn’t block out any light I can see it’s effect on the growth of the sweetcorn which is the veg nearest to it.
But how would these trees which are not overhanging the beans stop them from setting?