Landscape Fabric and Plastic:
Should They Be Used?



By Don Williams, the Tree Wizard





NEVER UNDER THE DRIP LINE OF TREES, SCRUBS, FLOWER BEDS OR HEDGES!

For years, porous landscape fabric has been recommended to be installed under trees and plants to prevent weed growth. This is the practice of most landscapers.


New landscape fabric is porous and allows water to pass through allowing the trees or plants to be watered. After a few years, the small holes in the fabric become closed as small sedimentary soil or plant debris stops up the holes causing the tree or plant to receive reduced water. After a few years the fabric holes completely close and no water passes thru the fabric. The tree receives little water and stresses and then die.


In 2018, a couple moved from out of state and bought a house on South Ridge in Georgetown. This is the area of town where most trees are in a declining condition, some with Oak Wilt and some declining from long term drought. The declining growth patterns are similar on other trees. We were presently treating the declining trees before she purchased the house. The main live oak in front was not responding to treatment. The remainder of trees were improving wonderfully.

The couple came from out of state in preparation to move here. We were discussing the trees and she asked why all the trees were looking good except the large live oak in front. it’s not unusual for some trees to respond to treatments slower. Some trees are usually in worst condition or have other unknown issues that are not readily apparent.


During the conversation, she pulled up some mulch and uncovered some older landscape fabric. She was advised that older landscape fabric would prevent water transfer overtime as the small soil and plant sediment stops up the holes in fabric and water could not transfer through. This was about 4:00 pm that day. I advised her to turn the water on full speed for several hours as the ground under the fabric was dry. She started watering about 4:30 PM and said she worried about this for hours.


She left the water on until about 1 AM and then went out to check the water on the tree. She pulled up all the landscape fabric about 1:30 AM and told me that even though water had been running for hours on top of fabric the ground under the fabric was still dry. This tree had not been properly water for many years because the fabric stopped water passage. There were a few leaves left on the tree as happens when a tree is dying. I believe the tree is in terminal condition. Landscape fabric cloth may work for a few years, but, over time, the pores in fabric begin to close restricting water passage thru fabric.


SHOULD NON-POROUS SHEET PLASTIC BE USED UNDER TREES OR LANDSCAPES? WATER WILL NEVER ALLOW WATER TO PASS TO THE PLANT ROOTS BELOW.

Some landscapers will use this black or clear sheet plastic to save money. They might save $50.00 and this prevents the tree or landscape plants from receiving any water. This sheet plastic is a total water barrier to plants under it. This is most likely fraud as the landscaper knew this when making the decision to use sheet plastic instead of a landscape fabric.


We observe this regularly. About October, 2018 in Killeen, where a minister had contracted with a well known referred landscaper. Around all of his nine or more mature oak trees this landscaper installed non-porous black sheet plastic under the drip line of all trees. Within a few months all the trees begin to die as the water was completely shut off from the tree roots. We recommended to remove the sheet plastic as soon as possible. I checked back several months later, around Christmas time and it was not removed. They said they did not have time yet. We treated the trees to help overcome the issue in October. If the fabric is not removed the trees will soon die.


Using the porous landscape fabric is also not recommended by us. Over the years the ability of water to penetrate the fabric will decrease as sediment and decayed plant debris stops up the micro size holes in fabric. This slows or stops water after a few years from penetrating the soil and roots below.


Just because the tree or landscape company is referred to you and is well known doesn’t mean they are knowledgeable. Some people lack the motivation to do what is right or lack the intelligence to perform what you assume to be an easy task.


Those landscapers will continue to use the sheet plastic on most jobs so the issue continues. Read the article on landscape fabric for more information.


Have any questions about this tree topic? Give Big Country Trees a call at (512)983-4148.





A tree can grow healthy and large without the aid of fabric or plastic. Call us and we'll tell you how.