Answer: There are a number of possibilities in terms of trees for containers. You could certainly grow some of the dwarf citrus trees in large containers, treating them as conservatory plants to be brought indoors for the winter. You could also consider smaller forms of Japanese maple. For a tall and narrow columnar tree you might consider the evergreen "Skyrocket" juniper. Finally, a number of naturally narrow, traditional fruit trees have been developed specifically for this type of use and can also be pruned to suit your sapce if needed. Larger garden centers may stock any or all of these with the possible exception of the specialty fruit trees. For fruit trees you might contact specialty nurseries such as Miller Nurseries ( http://www.millernurseries.com/ ) 1-800-836-9630 or Stark Brothers ( http://www.starkbros.com/ ). Jackson and Perkins ( http://www.jackson-perkins.com/cgi-bin/ncommerce3/ExecMacro/... ) 1-800-292-4769 specializes in roses but also carries some specifically columnar apple trees.
Q&A Library Searching Tips