There is a battle that all gardeners must face. The conditions necessary to grow beautiful crops and lawns are also some of the ideal conditions for growing weeds. As such, weed barrier is often used to smother weeds and prevent their growth in a garden. But will applying a weed barrier allow water through so that it can reach your precious plants’ roots?
Some weed barriers will drain water. Most landscaping fabrics are designed to allow air and moisture transmission, while most organic barriers such as straw, hay, and grass clippings will also promote moisture diffusion.
With that said, arguably the most effective weed barrier–plastic sheeting–is impermeable when new and will not drain water. Keep reading to discover all there is to know about how weed barriers drain water!
Water can get through most weed barriers. The exception would be plastic sheeting. It is an impermeable, non-biodegradable material that will not permit the passage of water.
However, even with plastic sheeting, there are a couple of points to keep in mind in regards to permeability:
- You must cut slits for your plants in order to keep them from smothering as well. As such, you will still have to pull weeds from these areas.
- Plastic sheeting will degrade and become brittle when exposed to UV rays for extended periods. This will lead to cracking due to pressure and impact. Weeds will emerge through these cracks and can become quite insidious, so it is necessary to replace plastic sheeting every few weeks to maintain its effectiveness as a weed barrier.
Other forms of weed barriers are much more permeable. Hay, straw, lawn clippings, and creeping plants will all slowly diffuse water.
Some gardeners note that paper and cardboard become less permeable once they dry in the sun.
While sun-dried paper can cause quite a bit of water to roll off, it is also important to remember that these products are biodegradable and break down in the soil rather quickly, so they will not create an impermeable barrier for long.
Yes, most landscaping fabrics let water through. They are usually made of woven polypropylene polymers (a type of thermoplastic) that are porous to allow air and moisture transmission.
This makes most landscaping fabric good for hardscaping because it will not cause the stone to erode.
However, there are some types of landscaping fabric that are much more impermeable. When designed specifically as a weed barrier, the polypropylene can be woven more densely to more closely resemble the nonporous benefits of plastic sheeting.
It depends. The traditional landscaping fabric designed as a flexible geotextile from polypropylene does have strong drainage properties. Its purpose is to maintain a durable landscaping base that will promote moisture absorption and minimize runoff.
Other types of organic weed barriers, such as mulch, straw, and lawn clippings, are also good for drainage. There are even some inorganic mulches that allow moisture diffusion.
However, plastic sheeting is arguably the most effective form of weed barrier, and it is not good for drainage. It is inorganic and impermeable and will cause water to runoff–rather than be absorbed by the ground–when in good condition.
Yes, it is generally good for weed barriers to drain water. Gardeners need their cultivated plants to receive water in order to grow, so permeability of a weed barrier is ideal.
However, permeability often comes with a tradeoff. Those weed barriers that allow water transmission come with pores through which weeds can sprout.
Therefore, the most comprehensive way to stifle weed growth is with an impermeable plastic sheeting. You just have to remember that water your cultivated plants will take a little more attention to detail.
It is also important to remember that there is no weed barrier that is completely effective at weed-proofing. A good weed barrier will slow the growth of weeds, but it will not eliminate weeds altogether.
Even plastic sheeting will break down and crack, allowing weeds to sprout. They will also grow through the slits in which you placed your cultivated plants.
If you are willing to still commit some time to basic weed pulling and maintenance, a permeable weed barrier should be plenty effective for its purpose.
Weed paper will usually let water through. Although paper will absorb some water, it cannot hold much water for long and will eventually become permeable.
Think of how a coffee filter holds water for a short period before slowly releasing the coffee into the carafe.
Paper will become much less permeable once it has dried in the sun. Once all of the moisture has left the paper, it cakes to the ground almost like a plaster that can cause more water to run off than to be drained. However, paper is biodegradable and will ultimately break down and let water through.
There is also a special type of landscaping paper commonly known as “paper mulch.”
It is fabricated from wood pulp and operates similarly to plastic sheeting. It absorbs heat from the sun to warm the ground, prevents water evaporation to keep the soil moist, and smothers weeds from sprouting.
While it is mostly impermeable when new, it will start to break down toward the end of the growing season and allow some moisture to pass.
Most weed barriers will drain water. The popular landscaping fabric seen in many lawns and gardens is a fabricated geotextile designed to allow air and moisture to pass.
However, many gardeners prefer the efficacy of plastic sheeting as a weed barrier, and it is an impermeable product.
Other materials, such as mulches, creeping plants, and papers, will all have various levels of porosity, so it is important to decide how much permeability you need for your landscaping before making a decision on a weed barrier!