When we were in London in February 2009, we visited Kew Gardens and in the Temperate house I saw a planter which held an orange tree. I really liked the planter and took some photos. I knew I wanted to build one like it, but didn't have any plants at home that would look right in it.
Recently, friends of ours gave us a Hardy Banana plant and I knew what kind of home it was going to get.Construction:
Their version was about 3-4 feet high while my version is roughly a 13 inch cube. The sides are left over cedar wall/ceiling tongue and groove from the downstairs bathroom ceiling project(circa 2001). I couldn't make the planter much larger because the cedar planks were not too thick and would probably require more support than at just the corners. Also, our yard is not huge and a much larger planter would look out of place. The corners are 3/4 inch aluminium angle and the rod holding it all together is 1/4 inch threaded rod. Initially, I added split ring lock washers, but I felt that I had to put too much tension on the rod to compress the lock washers. More tension than required to keep the planter together. I also deviated from their simple planter because the thickness of my planks were not as thick as the angle. I had though about using thinner angle and rod, but I didn't think it would look right. Two opposite walls of the planter are attached to the angle using brass brads pushed through holes drilled through the metal and wood then bent over on the back of the wood.
The other 2 sides of the planter have the angle screwed to a L shaped piece of wood 3/4" x 1 1/2" and the height of the planter. This allowed the cedar to be slid between the angle and the wood. Holes were then drilled in the angles for the rod and then the rod was slid through the angles and the planter walls were together.
The base is made from some 1"x3" pressure treated wood and 1"x4" planks nailed to 2 supports cut from a scrap pressure treated 2by4. I drilled 1/2 inch holes in the base and spread a thin layer of asphalt cement on the base and the insides of the planter for additional water resistance. My planter has the silver color angle and the other is the Kew Gardens version.
The plant:
These photos were taken at the Staten Island Botanical Gardens on the grounds of Snug Harbor . The plant can be left outdoors, but needs to be well mulched like a fig tree or cut back to the ground and well mulched. It is supposed to become more hardy the larger it gets.
Planting:
I put 3-4 inches of gravel at the botton of the planter and on top of that I put some hardware cloth with a 1/4 inch grid. The plant had already started to become root bound in the pot it had been transplanted into so I know it was growing well. I added about 5 inches of soil over the gravel and planted the banana, finishing the top with some cedar mulch. I may bring the plant in over the winter depending on how well it does and how big it gets. Here it is in our backyard.