Weed fabric can block weeds from germinating and encroaching upon our plants. However, this strategy should be used only in certain circumstances.
Weed fabric is a barrier laid on the soil surface. Holes are either cut or burned through the fabric where desired plants are allowed to grow. Some gardeners lay mulch on top of the fabric to hold it in place and for aesthetics.
One problem with using weed fabric is weed seeds can establish on top if mulch is in place or if soil erodes over the fabric. Weeds can also protrude through the openings cut for plants. Perennial weeds that establish in these areas can be especially difficult to remove because of the deep root system. Hand pulling these weeds often pulls up the weed fabric as well. Attempting to remove weed fabric after it has been in place for several seasons can be damaging to the root system of plants in that area.
Weed fabric is sometimes used for row crops of annuals such as cut flowers or vegetables. However, because it’s inorganic it does not break down and contribute to the health of the soil as organic mulch does. It also is likely to break lose during our Kansas wind episodes and become completely ineffective.
For perennial gardens, organic mulch such as wood chips is a much better option. When selecting an organic mulch for your landscape, choose a large, coarse material such as pine bark and apply at least three inches over the soil. Finer materials may promote weed growth so they should be avoided for mulching purposes. Some gardeners use a layer of cardboard or newspaper as an alternative to weed fabric. The nice thing about this option is it will break down into the soil over time. However, there can still be the issue of weeds developing on top of the paper layer.
Inorganic mulches such as rock can be expensive and difficult to apply. They also can radiate heat up to the plants which is not ideal, especially during summer. Rubber mulches can leach metals into the soil. For landscape purposes, inorganic mulches are not recommended.
For more information about mulch options in the landscape check out our turfgrass blog post: https://blogs.k-state.edu/
