Getting a lush green lawn without using chemicals involves a combination of good lawn care practices and natural solutions. First, start by mowing your lawn at the right height, typically around 3 inches, to promote strong root growth and help shade out weeds. Secondly, aerate your lawn to allow air, water, and nutrients to reach the roots. Thirdly, water your lawn deeply and infrequently to encourage deep root growth and avoid shallow, weak roots.