15 Purple Liriope Plant Rooted Starter Plugs / "Monkey Grass" Lilyturf
Liriope can be planted almost any time, from spring to fall,  It grows and spreads quite rapidly; depending on the type, some grow larger and quicker than others. Watering and fertilizer play a big part in its growth rate. 

 This plant is tough plants and can grow in sandy or clay soil and full sun or part shade. The only "must-have" is that it is a well-draining soil. Plant each liriope about 1 foot apart, keeping in mind that L. Spicata will spread, as it's a creeping plant. It's not necessary to divide the plants, though you can every three to four years.