Landscape fabric is the most common choice, but cardboard works just as well and costs less
Before you spread mulch, you need a barrier between the soil and the mulch itself. That barrier stops weeds from pushing up through the mulch and keeps the mulch from mixing into the soil as it breaks down. Landscape fabric — a thin, woven or non-woven cloth — is what most garden centers sell for this job. Cardboard, old newspaper, or even nothing at all are also options, depending on what you have on hand and how long you want the barrier to last.
The choice matters because it affects how often you'll need to replace the mulch, how much weeding you'll do, and how much you spend upfront. A barrier that lasts five years saves you money over time. One that breaks down in a season means you're buying mulch again sooner.
Key Takeaways
- Landscape fabric is durable and blocks weeds for three to five years, but costs more upfront than cardboard or newspaper.
- Cardboard and newspaper break down faster — usually within one to two seasons — but cost almost nothing if you have them at home.
- Overlap your barrier by at least six inches on all seams so weeds can't find gaps between pieces.
- Wet the soil before laying the barrier so it stays in place and makes better contact with the ground.
- Landscape fabric works best in permanent beds; cardboard is better for temporary plantings or areas you plan to dig up later.
Landscape fabric: durability and cost trade-off
Landscape fabric comes in two types: woven and non-woven. Woven fabric is made from polypropylene threads and lasts longer — typically three to five years before it starts to break down. Non-woven fabric is thinner, cheaper, and breaks down faster, usually in two to three years. Both block weeds and let water through, which is what you want.
The upfront cost is higher than cardboard — expect to pay $0.10 to $0.30 per square foot depending on the brand and thickness. For a 100-square-foot bed, that's $10 to $30. The payoff is that you won't have to replace it as often, and you'll spend less time pulling weeds. Landscape fabric also doesn't break down into the soil, so it doesn't add organic matter the way cardboard does.
Landscape fabric works best if you're planting perennials or shrubs that will stay in place for years. If you plan to dig up the bed later or move plants around frequently, the fabric becomes a hassle because you have to cut it and patch it every time.
Cardboard and newspaper: cheap and biodegradable
Cardboard is free if you save boxes from deliveries or ask a grocery store for their produce boxes. Newspaper costs nothing if you have it at home. Both block weeds just as well as landscape fabric while they're intact, and both break down into the soil within one to two seasons, adding organic matter that improves soil structure.
The trade-off is that they don't last as long. By the second season, cardboard starts to fall apart, especially in wet climates or if you water overhead. Newspaper breaks down even faster. Once they're gone, weeds come back unless you replace them. For a permanent bed, you'd be laying down new cardboard every year or two, which becomes tedious.
Cardboard works well for temporary beds, for areas where you're planting annuals you'll dig up at the end of the season, or for suppressing weeds in a new bed while you decide what to plant. It's also the right choice if you want to improve your soil over time without adding plastic to your garden.
How to lay down the barrier correctly
The barrier only works if it covers the soil completely and stays in place. Start by clearing the bed of existing weeds and debris. Wet the soil lightly so it's damp but not soggy — this helps the barrier make contact with the ground and keeps it from shifting.
Lay the fabric or cardboard in strips, overlapping each piece by at least six inches. Weeds will find any gap, so don't skimp on overlap. If you're using landscape fabric, pin it down with landscape staples or rocks every few feet so wind doesn't lift it. If you're using cardboard, overlap is usually enough to hold it in place, but you can weight it down with rocks or mulch as you spread it.
Cut holes or X-shaped slits for plants that are already in the ground. For new plantings, you can lay the barrier first and cut holes where you want to plant, or plant first and cut around the plants. Either way, make sure the barrier covers all exposed soil.
Other options: wood chips, straw, and bare soil
Some gardeners skip the barrier entirely and plant directly into the soil, then mulch on top. This works if you're willing to pull weeds more often, especially in the first season. Weeds will come up through the mulch, but they pull out more easily from loose mulch than from compacted soil.
A few gardeners use wood chips as a barrier instead of fabric or cardboard. Fresh wood chips break down slowly and can suppress weeds on their own, but they're not as reliable as a dedicated barrier. This approach works best in informal settings like a woodland garden where some weeds don't matter.
Straw is sometimes used as a temporary barrier in vegetable gardens, but it breaks down quickly and can introduce weed seeds if it's not high-quality weed-free straw. It's not a good choice for ornamental beds.
Comparing barriers: durability, cost, and effort
| Barrier Type | Upfront Cost | Lifespan | Best For |
|---|---|---|---|
| Woven landscape fabric | $0.20–$0.30 per sq ft | 3–5 years | Permanent beds with shrubs or perennials |
| Non-woven landscape fabric | $0.10–$0.15 per sq ft | 2–3 years | Medium-term beds where cost matters |
| Cardboard | Free (if you save boxes) | 1–2 seasons | Temporary beds, annual plantings, soil improvement |
| Newspaper | Free (if you have it) | 6–12 months | Quick weed suppression, temporary use |
| No barrier | $0 | N/A | Low-maintenance tolerance for weeds |
Common mistakes that reduce barrier effectiveness
The most common mistake is not overlapping seams enough. A one-inch overlap looks fine but leaves gaps for weeds to find. Overlap by at least six inches, and more if you're in a windy area or using thin cardboard.
Another mistake is laying the barrier on dry, compacted soil. If the soil is hard and the barrier doesn't make contact, water runs off instead of soaking in, and weeds can grow in the air gap between the barrier and the soil. Wet the soil first and press the barrier down firmly.
A third mistake is not cutting holes for existing plants. If you lay fabric over the base of a shrub or perennial, the plant can't get water, and the fabric can trap moisture and cause rot. Always cut a hole large enough that the barrier doesn't touch the stem.
Frequently Asked Questions
Can I use landscape fabric under mulch in a vegetable garden?
Landscape fabric works in vegetable gardens, but cardboard or newspaper is usually better because you'll dig up the bed at the end of the season anyway. Fabric gets in the way when you're turning soil or adding compost. Save the fabric for permanent beds.
How long does cardboard actually last in the ground?
Cardboard typically lasts one to two seasons depending on moisture and climate. In dry climates it lasts longer; in wet climates it breaks down faster. Waxed cardboard from produce boxes lasts longer than regular cardboard because the wax slows decomposition.
Do I need to remove landscape fabric before replanting?
You don't have to remove it, but you'll need to cut new holes and patch tears. If the fabric is falling apart anyway, it's easier to pull it out and lay down fresh material. If it's still intact, you can work around it.
Will landscape fabric prevent water from reaching plant roots?
No. Landscape fabric is porous and lets water through. The only way it blocks water is if it's installed incorrectly — laid on top of mulch instead of under it, or if it's so clogged with debris that water can't penetrate. Installed correctly, it doesn't affect water flow.
What's the difference between landscape fabric and weed cloth?
They're the same thing. "Landscape fabric," "weed cloth," and "weed barrier" all refer to the same product. The names are used interchangeably by different manufacturers and retailers.