Do you know why people all out in Qingming Festival? And why people planting in this day? As the saying goes: melon seeds before and after the tomb-sweeping day, the kind of beans.
一听清明节就想到扫墓，很严肃吧，其实完全相反，清明节是一年当中除了春节最热闹的节气，踏青、荡秋千、蹴鞠、植树等等。你今年的清明节小长假要怎么过呢？

Outing踏青

Outing also known as spring tour. In ancient times called the Tan-chun, look for spring and so on. On Tomb Sweeping Day, spring, nature, scene of thriving vitality everywhere, it is an excellent picnic time. China's civil society long maintained the clear hikers habits.
又叫春游。古时叫探春、寻春等。三月清明，春回大地，自然界到处呈现一派生机勃勃的景象，正是郊游的大好时光。我国民间长期保持着清明踏青的习惯。

Planting植树

Planting before Tomb Sweeping Festival, Chun-yang Zhao Lin, Chun-yu Fei Sa, planting seedlings with high survival rate, grow fast. Therefore, since ancient times, our country there is clear and bright tree-planting habits. It was Ching Ming Festival, also known as "Arbor Day." Custom has been circulating since planting.
清明前后，春阳照临，春雨飞洒，种植树苗成活率高，成长快。因此，自古以来，我国就有清明植树的习惯。有人还把清明节叫作“植树节”。植树风俗一直流传至今。

So, this is the reason why people do these things in this day every year. Qingming festival is one of the solar terms, and also a very important festival in China.
所以这就是清明节植树的原因。清明节也成为中国最重要的传统节日之一。