Teas that taste like Earth - Earthy, woodsy, grassy, and ancient tasting teas?
try Borntea : ) I really like their Shou Puerh
For me, liu bao is the earthiest tea. Shu puerh has more cereal and grain notes, and more sweetness overall. Aged sheng is earthy too, but in a more pond flora sort of way. Just depends what other flavors you want with your dirt!
When someone writes about earthy teas, first thing that come to my mind is high-quality Pu-erh and Keemun. Others are Yunnan and Assam.