Right off the bat - let's clear up the misconception that a magical effortless weed control method exists. It doesn't. Regardless of what you do, you're going to have to pull weeds at some point in time - but there are ways to make your job significantly easier! Weed seeds require the same thing all other seeds do to germinate: access to soil, sunlight, and water. Anyone who's ever broken land knows that bare soil begins to grow weeds almost immediately. This is due to the "seed bank" of thousands, perhaps tens of thousands, of weed seeds per square foot in normal soil just waiting for the right conditions to germinate. To prevent weed seeds from germinating, you need to block the existing weed seeds from sunlight or moisture in such a way that you don't prohibit the growth of the plants you do want.
While a cover of some type is a reasonable choice, landscape cloth isn't the type of material suited to covering soil for long periods of time. Regardless of what weed control method you use, seeds will still land on top and germinate. These will need to be pulled regularly. Before we get into a better alternative, let's first examine landscape cloth as an option.
Landscape cloth is found everywhere and is often labelled for weed control but does it really work? Well, sometimes yes it does. Landscape fabric is great for agricultural weed control where the fabric is replaced often (typically when the entire crop is switched over), or for seasonal pathways in gardens and removed annually or, for its originally intended use - landscaping. As in, preventing soils from moving from one layer to another layer, such as in a raised bed or when working with sand layers supporting hardscaped rock pathways. However, it does not work well in home landscapes as a year-long weed control tool.
Typically, homeowners will clear their soil of weeds, cut landscape cloth to the shape of their beds allowing holes for existing plants, and add a layer of some type of rocky or organic mulch on top of the cloth to hold it down. Landscape cloth should never be used in this manner as a permanent weed control method. Why is that?
Problems with landscape fabric for long-term weed control include:
- Most people will accidentally damage their existing plants installing the (unnecessary) landscape fabric.
- It gets unsightly quickly. We've all seen those yards with landscape fabric peeking through the thin mulch or rock layer above it.
- Even when installed according to directions, the pores between the landscape fibres will fill with soil particles over time, impairing soil aeration and drainage. This adds unnecessary stress to your plant. Stressed plants become unhealthy plants that tend to be more susceptible to pests and disease.
- It is difficult to work in a flower bed that has landscape cloth in it.
- Landscape fabric tends to break down unevenly over time, leaving patchy holes and a difficult removal process.
- Pulling weeds out of landscape fabric is very difficult because weed roots become tangled in the fabric.
- If the landscape fabric has been in place for long enough for your flower bed to begin to fill in, pulling weeds or removing the fabric usually damages the nearby plants that you want to keep.
- Landscape fabric disrupts the ecosystem that many beneficial insects need to exist in your yard, working for you.
- And the most significant reason of all? There are more effective ways to prevent weeds that actually benefit your soil and plants, and can cost far less.
What is a better way?
Skip the landscape cloth and make your mulch layer thicker. Mulching to about 4 inches with a shredded bark mulch is ideal - though other options exist as well. Mulching will still not prevent weeds from landing on top and germinating, nothing will, but it will prevent new weeds from germinating in the soil. The few weeds that emerge in mulch are surprisingly easy to pull with a gentle tug because they're trying to root on top of the mulch. Other benefits of mulch include significant improvements to soil health, reduced winterkill, lower water needs, and improved habitat for beneficial insects. For more information on mulching, start with our Mulch and More Guide and then check out the rest of our Healthy Soils page for more detailed information on mulching.