Two ornamental plants in the landscape that are commonly sheared are liriope and ornamental grasses such as pampas grass. Shearing in late winter removes old growth and makes way for new shoots.
Liriope
Annual removal of liriope foliage is not a necessity; however, cutting back is desirable if severe winter injury to the foliage has occurred. Running a lawn mower over the plants is a practical means of removal. Hedge shears may be a more practical means for large individual clumps.
In Georgia, new growth often begins to emerge in February and March; therefore, prune earlier or plan to cut back high to prevent injury to the new shoots.
Mondo grass (also called monkeygrass or Ophiopogon) redevelops slowly after severe pruning. Do not shear these plants.
Homeowners and maintenance personnel often neglect fertilizing lilyturf and thus do not obtain maximum vigor. A broadcast application of a general lawn or shrub fertilizer in early spring and again in mid-summer should be adequate to maintain the desired vigor.
Pampus grass
Prune pampas grass annually to remove the previous year’s foliage and make way for new growth. Pruning is best done in late winter, prior to the new growing season. Use hedge shears, lopping shears or power pruners to cut the plant back close to ground level. Be sure to wear a long-sleeve shirt and gloves when pruning to protect yourself from the sharp leaf blades.
After pruning pampas grass, apply a light, broadcast application of a complete fertilizer, like 8-8-8 or 10-10-10, to help stimulate new growth.
This is edited from these publications – where you can find more information.
Last summer was the first time I had liriope grass in my garden. Being a novice with the grass, I cut it back in the early fall. I just read that it should be cut back in March or late winter. Will this harm my liriope? When should I see new growth beginning? It is middle March and I do not see anything. Did I kill the plant? It is still green.