Hi, I recently moved back to Port Huron, Michigan and I work at a library. We have 4 large containers (approximately 33" H x 36" W. They look like clay pots but are hard plastic containers) in front of our library that we would like to plant with small trees. I was a Master Gardener in Colorado through the CSU Extension Program but the growing conditions and weather are very different between the two states. Rather than take a stab at picking anything, I thought I would come to the MSU Master Gardeners for guidance. If you know the phone number for the Master Gardeners office in Port Huron, I would welcome that. If you have any suggestions, I welcome that as well. I would be interested in a small tree that would do well in a container, can handle strong winds, rain and direct sunlight, cold weather, living very close to the St. Clair River, and minimal care. Also, if it had different looks depending on the season, that would be a bonus. Its a lot of particulars and you might want to suggest an ornamental shrub and at this point, I would appreciate anything. We have always planted annuals in the pots during the summer but I'm hoping we can find a year round solution and possibly  plant some perennials around the edge of the pot with the tree in the middle. I'm just not sure what is possible in a container in this climate. Thank you for your help and I look forward to hearing from you. Fran