So at first when I saw these big logs, I thought for a moment they would be a border for a very high flower bed. Then I realized they would be made it in to the most awesome planters!

So you will definitely  want a chainsaw and an ax for this project. You will hollow out the log, which is the biggest part of the project. Start by cutting sections in the log with the chainsaw then take the ax to it and begin to make it canoe like. 

After it's hollowed out, you fill it will soil and nutrients. Then cover the top with weed mat, cut the holes in the mat to be able to plant the flowers, then cover with saw dust, wood chips or even soil to cover up the weed mat. All in all a wonderful summer project worth the time.