Sayyed Mohammad Al-Musawi, Sayyed Mohammad al-Musawi is originally from Iraq and heads up the World Ahlul Bayt Islamic League in London. Other than being involved in various humanitarian projects, he frequently responds to... Answered 1 year ago

Grass itself is not part of the earth hence Tayammum on grass is invalid, but it the grass is covered by soil or clay, Tayammum will be valid on soil or clay or sand etc being part of the earth.