Yes, you absolutely put mulch on top of the soil to protect it, retain moisture, suppress weeds, regulate temperature, and improve soil health over time, essentially creating a natural forest floor effect for healthier plants. Apply a layer of 2-4 inches (5-10 cm) of organic material like wood chips, straw, or compost directly over the soil surface, keeping it a few inches away from plant stems.
Yes, you absolutely put mulch on top of the soil to protect it, conserve moisture, suppress weeds, and regulate soil temperature, creating a healthier environment for plants by mimicking a natural forest floor. Apply a layer (usually 2-4 inches deep, depending on the mulch type) over the existing soil surface, keeping it away from plant stems and bulbs to prevent rot, notes Bunnings and this YouTube video.
What do you use before laying down mulch? sheets of cardboard or thick layers of newspapers. NEVER any kind of plastic or something that does NOT decompose... Various things can be used as a weed blocker. Probably the cheapest and easiest to lay is newspaper. 3 or 4 layers will keep weeds from growing through.
Mulching's disadvantages include attracting pests (slugs, rodents, termites), promoting fungal diseases and root rot if applied too thickly or against stems, hindering water/oxygen penetration (leading to suffocation), potentially depleting soil nitrogen (with fresh wood), overheating soil in summer, and increasing initial costs and labor for large areas, with poor quality or fine mulches sometimes repelling water, say Ozbreed Plants and Real Simple.
More mulch is not always better – if applied too thickly, it can prevent rain and irrigation reaching the plant roots. The amount needed varies based on the product, but for bark mulches, aim for around 3-4cm.
You can mulch any time, but early to mid-spring (April/May) is often best for weed suppression and moisture retention as soil warms, while fall (September/October) is great for insulating roots before winter. Always mulch when the soil is damp, not frozen or overly wet, and avoid applying it too heavily around new plants to let them establish.
While the material itself does not draw termites to the area, mulch spread over three inches deep creates an inviting habitat for the pests. Layers of organic matter trap heat and moisture next to the ground. Termites use this thick mulch as shelter from harsh weather. Some kinds of mulch may even repel termites.
The worst time to mulch your garden beds is during early spring or when the soil is still cold and wet. "If the soil is still cold and soggy, mulching can trap moisture and stunt growth," says Betz. Mulching too early can also keep the soil sold, which may cause plants to bloom later or not at all.
For the best weed suppression in Australia, use thick layers (5-10cm) of chunky woodchips, pine bark, or hardwood chips, as they block sunlight effectively and last well. For veggie patches, straw or lucerne mulch is excellent for nutrients and weed blocking, but needs regular topping up. Inorganic options like landscape fabric or gravel also work but offer no soil improvement.
Organic mulch doesn't just sit on the surface of your soil—it slowly breaks down, feeding the earth with organic matter and nutrients. This process improves soil structure and encourages healthy root development by increasing beneficial microbial activity.
Landscape fabric is a synthetic material—typically made from woven or nonwoven plastic—that's laid under mulch or stone to block weeds. It promises to stop weed growth by cutting off sunlight and conserving soil moisture. For DIYers and first-time homeowners, it can seem like a simple, low-effort solution.
Removing mulch before putting down new mulch is typically not necessary. Good mulch breaks down over time and adds nutrients to the soil. The best way to lay over old mulch is to rake the area flat before you start.
It dramatically cuts back on time required to remove the weeds that would have sprouted absent their smothering from sheet mulching. Earthworms love to feast on cardboard; as they do, they will both aerate the soil below and add valuable deposits of nutrient rich castings (“worm poop”).
Use the 2-3 inches of mulch recommended because this depth controls weeds and grass, and helps prevent the soil from drying out too quickly. Too little mulch and you get no benefits. Too much and you risk roots growing in the mulch and not the soil, as well as crown rot .
There are some species that tolerate excessive mulch better than others. Some of the worst effected plants are grassy plants (iris, daylilies, liriope, etc.), Indian Hawthorn, Azaleas and Loropetalum.
12 Cheap Ways to Cover Dirt in Your Backyard
For excellent weed control, use thick layers (4-6 inches) of wood chips/bark, straw, shredded leaves, or grass clippings to block sunlight and prevent weed seeds from germinating, with inorganic options like gravel/rock offering long-term, non-decomposing barriers, while cardboard/newspaper under organic mulch provides a strong initial weed barrier. The best choice depends on your garden's needs, balancing weed suppression with soil health and aesthetics.
Finally, avoid large, bark type mulch or big wood chips. Since these big pieces take a long time to decompose, and they end up depriving the soil and plants of nutrients.
Fill a spray bottle with white vinegar and spritz them fully, trying to get as close to the roots as possible. Normal vinegar will also do the job, helping you to get rid of weeds permanently.
Mulching's disadvantages include attracting pests (slugs, rodents, termites), promoting fungal diseases and root rot if applied too thickly or against stems, hindering water/oxygen penetration (leading to suffocation), potentially depleting soil nitrogen (with fresh wood), overheating soil in summer, and increasing initial costs and labor for large areas, with poor quality or fine mulches sometimes repelling water, say Ozbreed Plants and Real Simple.
You can mulch any time, but early to mid-spring (April/May) is often best for weed suppression and moisture retention as soil warms, while fall (September/October) is great for insulating roots before winter. Always mulch when the soil is damp, not frozen or overly wet, and avoid applying it too heavily around new plants to let them establish.
Get Rid of Weeds Before Mulching
It's much more effective to remove large and numerous weeds before adding mulch to your garden, as they can otherwise reemerge or continue spreading beneath it.
Attracts pests: Because mulch is organic, it can draw pests such as termites and carpenter ants. These insects may eventually find their way into nearby structures.
Clemson University scientists reported that 'Termites hate smells of cedarwood, geranium, and tea tree oil. It has also been found that clove bud, cinnamon, and garlic oils can also repel termites.
Instead, choose a low- or no-cellulose ground cover like: