From planting a vegetable garden to native trees or flowers or helping others plant or donating to causes or venues that do planting or regeneration work or even spreading awareness to others of the importance of plants to our world is vital work.
Planting trees and shrubs not only provides food and habitat for the non-human world but gives the newly planted seed or seedling a chance to fulfill its chance to grow from seed to adult and fulfil its life in the community of life about it.
It's wonderful to give something back to the Earth after we receive so much.
Planting a vegetable garden is another way of getting close to the Earth and the results are very satisfying and tasty.
Below are some links on planting:
Gardening with children
By Brendon Crook