Last year 5 of my european pears grew really really well but it was not growth I wanted. Last year my 4 year old pears sent out shoot from just above the graft (scion growth) that was over 1 inch in diameter and over 7 ft high. The first one they made after about 2 ft I pruned it off. But they made anther one so I just let it be to see what it would do and it got over 7ft high and almost as large as the main trunk. Why would my pears do this? Is there too much nitrogen in the soil? too much water? (we had about 20 inches of rain each month of may june july and august about 80 inches total) Am I over fertilizing? I give them some 15-5-10 in spring and summer to encourage growth based on trunk diameter and years in the ground. I would like to know why my pears did this and how to avoid them doing it next year.