spell to heal the earth
plant a small tree, bush or local flower from seed. Bless the soil it is placed in, bless the water you use on it and allow it full moonlight when the moon is full.
When it is strong enough, take it to a place where it is native and will not upset the ecosystem. Do not plant herbs as they can be destructive.
As you plant it, say:
"Gentle goddess, mighty earth
take this offering of mine
Blessings I shower upon your earth
And heal you in the fullness of time."