Sheet mulching
Various inorganic and organic materials can be used as mulch. Mulch materials vary in their benefits and drawbacks, and some plant pathogens can be spread in certain types of mulch.
Cardboard or heavy paper is sometimes applied as mulch and can be inexpensive and relatively easy to apply. Sheet mulching can decrease weed growth until a newly planted ground cover fills in open spaces and grows enough to shade or crowd out weeds.
Solutions
First reduce weeds by mowing, flattening them down, or applying herbicide. Heavy paper (e.g., types commercially available in rolls) can then be applied on the ground to exclude light. This covering causes emerged annuals to die, and can suppress the growth of certain perennial weeds.
After application, you can make holes in the paper and plant through the sheets, similar to the methods used for geotextiles (landscape fabrics). Or you can apply the sheet mulch to bare and weedy areas after installing the plants and any irrigation system. To help keep the paper in place and improve the appearance, you can cover it with course, organic mulch.
Drawbacks are that paper hinders air and water movement. Rain and overhead irrigation tend to run off, which can favor weed growth at the paper's edge. Paper tends to break or tear after transplanting or if walked on.
Before applying sheet mulch, you may need to install a drip irrigation system beneath the paper. It can be difficult to tell whether soil moisture beneath sheet mulch is being maintained at levels appropriate for the healthy growth of desired plants.
For more information, consult Pest Notes: Weed Management in Landscapes. |
