hello

in new york south region

we have a patio with a red maple planted in a large 3' dia. pot. unfortunately the patio area gets very limited sun during the day. although the tree survives it does not flourish due to the limited sun. any tips on fertilization to help it be the best it can be given it's less than ideal environment? on the same patio, planted the same way we also have a butterfly maple and a steuardia.

any advice is appreciated

thanks