Tsutsuji (azalea) trees are common in both towns and mountains. In towns, azaleas are planted to absorb carbon dioxide, while those planted along roads act as safety barriers. In some cases, tsutsuji trees are planted along the edge of a mountain because they keep weeds from growing in that area and also allow people to enjoy their flowers. Tsutsuji planted near houses are frequently trimmed so that their branches grow into complicated shapes. They are extremely tough trees.