植树节是每年的3月12日，在这一天，人们会集体或个人参与到植树活动中来，为环境保护出一份力。植树节的来历可以追溯到我国古代，当时就有植树造林的传统，提倡“植树兴邦”。随着环境污染日益加剧，植树节的意义更加重要。

植树节的英语作文可以从以下几个方面展开：

1.意义：介绍植树节的来历以及其对保护环境的重要意义。可以用一些数据或实例来说明植树活动的效果，如提高空气质量、减少土壤侵蚀、改善水源等。

2.活动：介绍植树节的活动形式以及参与方式。可以提到相关组织或政府部门的举措，也可以分享自己或身边人参与植树的经历。

3.呼吁：呼吁更多的人加入到植树活动中来，弘扬植树节的精神。可以提出一些倡议或行动，如减少用纸、垃圾分类、节约水资源等。

范文：

Tree-planting Day

Tree-planting Day falls on March 12th every year. On this day, people, either in groups or as individuals, participate in tree-planting activities to contribute to environmental protection. The origin of Tree-planting Day can be traced back to ancient China, when the tradition of planting trees and building forests was advocated to 'make the country prosperous'. With the increasing environmental pollution, the significance of Tree-planting Day has become more important.

Tree-planting Day has several aspects to write about:

1. Significance: Introduce the origin of Tree-planting Day and its importance in environmental protection. Some data or examples can be used to illustrate the effect of tree-planting activities, such as improving air quality, reducing soil erosion, and improving water sources.

2. Activities: Introduce the form of Tree-planting Day activities and ways to participate. Some relevant organizations or government departments' measures can be mentioned, and personal experiences of participating in tree-planting can be shared.

3. Appeal: Call on more people to join the tree-planting activities and promote the spirit of Tree-planting Day. Some initiatives or actions can be proposed, such as reducing paper usage, waste classification, and water conservation.

In conclusion, Tree-planting Day is an important day to protect the environment, and everyone can participate in it. Let's work together to build a better world!