Face it! Most of us have been in the position of thinking that weed barrier will make gardening easier. Most of us who have tried it will say that it does not. Some of us get up a real head of steam (negative) about the subject.
To be fair(er) and try to discuss how weed barriers (plastic or cloth) work, consider the following:
What is the weed cloth supposed to do?
1. According to the manufacturer, this is supposed to keep the soil weed-free.
2. It is implied that the weed cloth will also keep mulch looking tidy.
What actually happens?
1. If the weed barrier is plastic, it will greatly and negatively reduce the amount of air and water that needs to enter and leave the soil.
2. The micro-organisms in the soil die because of the lack of oxygen. The soil beneath the plastic becomes anaerobic (deprived of oxygen).
3. Anaerobic soil can be devasting to plants that might be planted in the weed barrier area. We all can recognize this sick or dead soil. It is often slimy and slick. It can look as though it has a oil scum. Sometimes it has a foul smell.
What about weed control?
1. Most weed seeds need sunlight to germinate. In that sense the weed barrier is effective.
2. Many, many weed seeds are airborne and land in the mulch on top of the barrier and take root there.
3. If the weed roots penetrate the fabric (and they can), it becomes a mess.
If the weed barrier fabric (or plastic) doesn't work to control weeds, what does?
1. Mulch. This works because as the mulch biodegrades over time, it feeds the soil.
2. Weeds generally don't like humnus-rich soils. If they sprout, the roots are generally weak and they are easily hand-pulled.
Why was weed barrier cloth/fabric ever thought to be a good idea?.
1. It is an example of a process originally used in nurseries, windbreaks, etc that got moved into the area of home gardening/landscape.
2. Save your money. Mulch your plants.