Landscape fabric is a commonly used tool for preventing weeds in the garden, but it can sometimes be more trouble than it’s worth. Yes, it will block the growth of weeds, but often it can block other, unintended things like proper water absorption and delivery of essential nutrients.
Fertilizer can get through landscape fabric, but only if proper conditions are met. The landscape fabric must be properly installed, and the fertilizer must be in liquid form so that it can pass through the weave of the material. Granular fertilizers can only be used if you cut holes in the fabric.
The rest of this article will explain how to fertilize with landscape fabric, what types of fertilizer cannot be used with landscape fabric, as well as some of the benefits and drawbacks of using landscape fabric.
How To Fertilize a Garden Through Landscape Fabric
To fertilize through landscape fabric, you must ensure the following steps are followed:
- Install the landscape fabric correctly.
- Move away mulch and other surface coverings.
- Apply a liquid fertilizer with a handheld spreader.
Let’s take a look at each of these steps in detail.
Install the Landscape Fabric Correctly
One of the most important steps to successfully fertilizing through landscape fabric is to make sure the initial installation of landscape fabric is done correctly. If the fabric is installed poorly or facing the wrong direction, it can seriously interfere with its ability to pass water and nutrients through.
Landscape fabric comes in a variety of different forms and textures. If you plan to fertilize through the fabric, you will want to select an option that is woven and of high quality. Cheaper alternatives will often tear and lose their position much easier, creating a mess in your garden.
It is essential that the fabric is installed facing the right direction. Most landscape fabrics have a smooth side and a more textured side. The smooth side should always be facing up, towards the sky, while the rougher side should face down towards the earth.
This orientation will give water and nutrients the highest possible likelihood of successfully passing through the weave and reaching the soil and roots below. If you want to learn more about how roots fare with landscape fabric, I recommend my complete guide on the topic: Can Plant Roots Grow Through Landscape Fabric?
If the landscape fabric is installed incorrectly (facing the wrong direction, uneven, rippled), then there is a good chance you will experience pooling of water and inability to pass through the fabric, causing your plants to suffer from lack of exposure to necessary nutrients.
Move Away Mulch and Other Surface Coverings
To achieve the highest chance of fabric penetration, you will need to move away as much of the mulch or other surface coverings you have placed on top of the fabric. Exposing the fabric completely will make it easier for water and fertilizer to pass through.
Before replacing the mulch or other covering, be sure you have given the fertilizer long enough to soak into the soil. If you replace it too early, you are creating a barrier that might affect your soil’s ability to receive the fertilizer’s nutrients. Give it at least a day or two before covering the landscape fabric again.
Apply a Liquid Fertilizer With a Handheld Spreader
Because of the small weave of the landscape fabric, typical granular fertilizers will be unable to penetrate the soil. They will just sit on top of the fabric without delivering any of the nutrients you had intended for your soil.
To combat this issue, you should use a liquid fertilizer option. There are many powdered, water-soluble fertilizers available that can be mixed with water according to the manufacturer’s recommendations. To fertilize through your landscape fabric, you will need to mix up enough liquid fertilizer for your garden area and add it to a handheld fertilizer spreader.
Handheld liquid fertilizer spreaders often attach to a garden hose and create the liquid fertilizer as the water sprays through the nozzle into the chamber containing the powdered fertilizer. This handheld tool includes a spray nozzle that is adjustable for strength and width to achieve your desired application.
Using the handheld fertilizer spreader, spray enough liquid fertilizer to cover the area, following the recommended amount for your specific types of plants. Supposing the landscape fabric has been correctly installed and the mulch has been removed to eliminate additional barriers. In that case, the liquid fertilizer should sink through and reach the soil, fertilizing your plants.
Fertilizing Trees and Shrubs Through Landscape Fabric
You may have to get a bit more creative with your fertilizer application when fertilizing larger plants. Because larger plants often require a fertilizer spike rather than a liquid fertilizer, you’ll need to create slits or holes in the fabric to apply the fertilizer.
To do this, you will need to first remove any mulch or other surface coverings to expose the landscape fabric completely. Next, you will need to cut holes or slits around the base of the plant. These openings will expose the soil underneath, allowing the fertilizer to pass through.
About 18 inches (46 cm) away from the base of the plant, the slits should form a circle around the plant. Once complete, you will need to completely water the soil in that area. The ground should be soaked well through, softening the soil thoroughly.
Once the soil is soft enough to drive the fertilizer spikes through, you will want to place one fertilizer spike in the center of each hole or slit and then water once more.
Because you are creating gaps in the fabric, you will likely discover more weeds in these areas than in others. Keep an eye out and pull the weeds as they occur, so they don’t get too out of hand. The remaining landscape fabric should continue to do a good job keeping the soil weed-free.
Benefits and Drawbacks of Landscape Fabric
Landscape fabric is appealing to many gardeners because it promises to eliminate the never-ending issue of weeds. However, some say that landscape fabric causes more problems than it solves, which makes it a good idea to consider the pros and cons before installing it in your yard or garden.
Benefits of Landscape Fabric
Some of the main benefits of using landscape fabric in your outdoor space are:
- Prevention of weeds.
- Improves water retention in soil.
- Keeps mulch and rocks separate from the soil.
Landscape fabric, also known as a “weed blocker,” is often installed in order to prevent weeds from growing. Weed-pulling is a never-ending chore that many people opt not to do, so applying a weed blocker definitely has its appeal. When weed seeds are covered by the landscape fabric, it prevents them from being able to sprout, reducing the number of weeds that appear in your landscape.
Because the fabric effectively covers the soil, it creates an excellent environment for retaining water. There is an additional barrier between the soil and the direct sunlight, allowing the soil to absorb the water for longer than it would if the sun was causing it to evaporate more quickly.
When it comes to aesthetics, landscaping can become a real pain if the carefully placed mulch and rocks begin to sink in and combine with the soil. Landscape fabric prevents this from occurring by creating a barrier between the decorative items and the soil.
Drawbacks of Landscape Fabric
Some of the cons of using landscape fabric are:
- Potential clogs in the weave of the fabric prevent water from getting through.
- Organic material and earthworms cannot penetrate the fabric.
- Weeds still grow above the fabric.
Mulch and soil have a tendency to clog the openings in the weave of the landscape fabric over time, creating a complete barrier between the soil and the nutrients it needs. This can prevent fertilizer, water, and other necessary nutrients from getting through to the soil.
Organic material cannot penetrate the fabric either, so earthworms and other necessary organic components will not be able to create a healthy soil composition. This can cause your soil to become dry, crumbly, and unsuitable for any kind of plant growth.
Although landscape fabric is marketed as a weed stopper, it is important to understand that it only stops weed seeds that live under the fabric. If you place mulch or other organic materials on top of the fabric, weeds can still sprout above the fabric.
Although fertilizer can get through landscape fabric, it is often more trouble than it’s worth. In order to successfully fertilize your garden through landscape fabric, you must remove all debris and mulch and apply a liquid fertilizer thoroughly, allowing it to fully absorb before replacing any fabric covering.
To fertilize trees, shrubs, or other large plants, you must cut holes in the fabric and place fertilizer spikes within them in order to deliver the essential nutrients to your plants.
Because weeds can still occur even with landscape fabric, you might be better off skipping it altogether.