Complex sentence: Due to high maintenance costs however, grass courts are now rare as they must be watered and mowed often, and take a longer time to dry after rain than hard courts.
Split into simpler sentences: Due to high maintenance costs however, grass courts are now rare as they must be watered and mowed often. Therefore, it is harder to play on grass courts than on hard courts.Grass courts also take a longer time to dry from the rain than hard courts.