Weeds growing IN mulch on top of landscape fabric
I laid a layer of premium landscape fabric in the kids playground area. I laid a few inches of playmat mulch on top. I am having a problem with weeds growing on top of the fabric, within the mulch. I pull the weeds and a few weeks later, the area is filled again. The weeds grow in the mulch and the roots spread across the top of the fabric.
This is a large area (20x20) so it becomes very time consuming. I do live on a lot with no other homes built around me (fields of weeds). I have a large number of other landscape areas that have the same fabric with different mulch and I have no problems with weeds growing in the mulch.
Currently there is only an inch or 2 of mulch remaining. I'm at the point that I need to decide to add more mulch or perform more drastic measures.
As this is a children's play area, I'm hesitant of putting down any chemicals.
Is there anything I can do for this? After many years of pulling weeds, I've had enough.