Proper mulching creates a healthy landscape

Published 11:45 pm Tuesday, April 15, 2014

Adding mulch to your landscape gives planting beds a neat and uniform appearance. However, mulching serves a much greater purpose than to just be aesthetically pleasing; it is one of the easiest ways to maintain healthy landscape plants.  

Mulch applied to flower beds, vegetable gardens and around trees and shrubs decreases pressure from unwanted weeds. Many weeds that germinate from seed will not be able to sprout under mulch. Perennial weeds, such as sedges, are suppressed and more shallow-rooted making them easier to pull by hand.  Pine straw is one of the best mulch options in Louisiana and is readily available. Wood chips, pine bark, chopped leaves, dried grass clippings and straw also work well.

Mulch helps to regulate soil temperature. Plant roots are cooler in the summer and warmer in the winter. If you choose to use plastic mulch in the summer, select white not black in order to prevent plant roots from becoming too hot. Mulch maintains soil moisture by reducing evaporation. Gardeners can water less frequently, and the likelihood of soil moisture fluctuations decreases. Many vegetable plants are sensitive to soil moisture fluctuations, especially tomatoes.

Mulching to a depth of two to three inches is sufficient in most situations. When applying mulch be mindful to go out and not up. This is extremely important around trees and woody ornamentals. Often mulch is mounded in a volcano-like pile around the base of trees. This can be very detrimental, hindering oxygen exchange to the roots and resulting in disease and decay of the trunk.

Over time as mulch decomposes, organic matter is added to the soil, improving soil aeration, structure and drainage. Do not remove old mulch; simply add a new layer of mulch over the top when it is needed. If mulch becomes matted use a rake to break it up and refresh the appearance.  

For more information contact the St. John Parish LSU AgCenter Extension Office at 985-497-3261 or visit Applications are still being accepted for the 2014 River Region Master Gardener Class. Please contact the St. John or St. Charles Extension Office to sign up.


Mariah Bock is the LSU AgCenter county agent for St. John Parish. She can be reached by email at