The Feria de Las Flores the flower parade is held during the month of August. People come from all over the world to absorb the rich culture, filled with bright colors and beautifully decorated floats and lots of flowers arranged so creatively.
This festival has many events; horse drawn rides around town, an orchid competition, music festivals, and parade of silleteros. The first ever festival took place in May 1957 and only lasted 5 days. It was invented to celebrate the rich botanical culture of Colombia. But today it happens in the city of Medellin in August and the celebration lasts a full week.
http://discovercolombia.com/medellin/events/the-flower-festival/