I've seen them 5' tall and 8' or more across but then we tend grow things big out here :-)) And it takes a very long time to achieve that size. Plant tag info is often incorrect and with trees and shrubs, typically reflects a 10 year size. Sources indicate mature size to be 5' tall and 10-12' wide.

Robins are birds that I enjoy viewing, but not as they try to build nests under our porch lights which are on both sides of an area right by our front entrance door. For three days my husband has removed the straw, twigs, etc in order to prevent a completed robin's nest. They put the straw, twigs, etc. up, he takes them down immediately. Today after reading these posts, I sprayed the area with ant and roach spray that I use when the ants try to visit too close to our outside walkway. Two robins just came with straw in their mouths, but they flew away. I hope this is a long-term solution. This is the first time that we have had this problem in the nineteen years that we have lived here. I am already tired of the mess on our porch and the potential health hazard presented if the robins succeed in building a permanent nest. We have plenty of trees that the birds usually choose for their nests and are still quite welcome to do so. However, why our porch this year is a puzzle. Thanks to all who have posted for their solutions. To the haters, because one does not want a bird's nest in an area that he/she frequently uses in his/her home, does not label the person as an animal hater. Why should my quality of life be compromised daily upon trying to enter my home for the sake of a bird's nest? The answer is that it shouldn't and will not. We will win this fight and reclaim our safety and keep our good health.

Here are some ideas from a previous thread. Here is a link that might be useful: nesting

How high up is it and how close is it to other structures? I think one of the best things you can do is never walk up to it anymore....which leaves your scent. But answer my other questions and I might think of other possibilities. I just had a carolina wren nest on a table on my porch (in a pot, in a tub) destroyed by a feral cat. :(