Both Mondo and Liriope prefer growing in the shade and do well in areas that are too shady to grow grass.In addition, mondo produces a dense mat of roots that helps prevent runoff. Both types of monkey grass also do well on steep slopes where it's difficult to grow turf grasses. Mondo has the benefit of never needing to be mowed, making it a low-maintenance lawn.
Although Mondo is usually grown as groundcover, it can also be used as a border for walkways and plant beds. Use Liriope muscarii, the clumping variety of Liriope, as a border or edging; Liriope spicata -- the creeping form -- can be invasive. Monkey grass produces purple or white-spiked flowers that are very attractive as edging material.
Shrub-like forms of mondo grass, which grow between 10 and 15 inches tall, can be used as foundation plantings. These varieties are usually evergreen. Mondo grass is also used in rock gardens, around garden ponds or along streams. Dwarf varieties are used between stepping stones. Liriope can be planted at the bases of shrubs that don't have leaves growing near the ground, while creeping liriope can fill in bare spots in a garden.
Monkey grasses are hardy, low-maintenance plants that grow in a wide range of soils. They're resistant to drought and weeds and don't have many problems with insects or disease. In addition, they rarely need to be fertilized.
Pythium root rot can be a problem for monkey grass. Symptoms include tip burn, yellowing and browning of leaves. As the disease progresses, the crown separates from the base. Control pythium with fungicidal drenches and add a layer of compost to the surface of the soil. Liriope plants may also suffer from anthracnose. This fungal disease causes reddish streaks to appear in the leaves, beginning at the tips. Only older leaves are affected. Apply fungicides as a preventive before symptoms appear. Scales are the main insect problems for both types of monkey grass. The problem is mainly a cosmetic one since they cause spots on the leaves. Control scales by spraying with an oil-based insecticide.