Once upon a time, the grounds surrounding the Maryknoll Sisters home in Monrovia were 6.5 acres of lushly green lawn and trees. They’ll never be that way again — not with water being so rare and expensive these days — but the retired nuns of Maryknoll Sisters of St. Dominic, about 15 former nurses, teachers and social workers in their 80s and 90s, are working with Grow Monrovia and other conservation activists to find a better use for their land. Their vision involves converting the mostly dead and dying lawns “to something more suitable to the environment here,” said Sister Arlene Trant, 76, coordinator of the order’s retirement facility. Their…