Karen Cambre, Sharpe, Kenneth W.
News article for January 29, 2018
What a wet cold winter. It has been hard to get anything accomplished outside. It is either too cold or too wet.
I would take advantage of any breaks in the weather to perform winter chores that need to be accomplished before new growth starts to emerge. This far south plants do not need much warm weather to start breaking dormancy and many times that occurs in February.
Ground covers, like liriope, can look pretty ragged after a severe winter like we have had. The foliage quality can get pretty bad, but the plant will respond favorably to pruning. It is important to prune liriope prior to the emergence of new foliage. Should you cut it back after new leaves appear you will clip the new growth and the blades will have square ends instead of round edges. You will also be left with brown edges for the remainder of the year where the cut damaged plant tissue.
The liriope that I have looked at has a lot of brown tips and is drooping from the weight of snow and ice. It would be best to prune it back in February and then you will only see the clipped look for a few weeks. Your reward will be fresh, high quality foliage that is very attractive.
There are several ways to cut liriope back, but my preferred method is to use a string line trimmer. Cut back foliage to within 2 to 3 inches of the soil. The only concern is where you have woody ornamentals or other plants in a bed with your ground cover. Be sure not to hit the bark with your string or you can girdle shrubs and kill them.
Another method for trimming ground covers is to use your lawnmower. If you can get to your bed or border with the lawn mower, this is a very easy option. Make sure you have a good sharp blade. Set your blade height between 2 and 3 inches and mow over the top of your ground cover. I would mow it twice in opposite directions, which will give you a cleaner and more uniform cut.
If you have small areas that need to be pruned or areas right up next to other plants that are not to be damaged or pruned, you can use hand or shrub shears. This method is much slower, but in tight quarters it is safer and more accurate.
I would not routinely prune back Mondo grass, which you may know as Monkey grass. It grows at a slower pace and recovery is much longer if you do cut it back.
Ornamental grasses can also be cut back in February. Once they go dormant you can still enjoy their dried foliage and plumes swaying in the wind, but I would prune them now in advance of new growth. Cut dried foliage back to within 3 to 5 inches from the soil.
This pruning task is best performed with a sharp pair of shears.
When the weather starts to warm up at the end of February or early March, you will want to fertilize ground cover beds with 2 pounds of 8-8-8 fertilizer, or the equivalent, per 100 square feet of bed area.
The LSU AgCenter and the LSU College of Agriculture