Why Mulch Is Your Garden's Best Friend

A protective layer for your soil

Of all the jobs in the garden, spreading a good layer of mulch is one of the simplest and most rewarding. It takes very little skill, costs relatively little, and the benefits to your plants are significant.

Mulch is any material laid over the surface of the soil. Common choices include sugar cane, eucy mulch, wood chips or even gravel. It works much like a blanket for your garden beds, protecting the soil, reducing moisture loss and creating better growing conditions for everything planted beneath it.

Given Australia's hot summers, variable rainfall and recurring water restrictions, mulching is one of the most worthwhile habits a gardener can adopt. Here's why.

It conserves water

This is the most important benefit. Bare soil exposed to the afternoon sun loses moisture quickly, and on a scorching, windy day it can dry out within hours. A layer of mulch shades the soil and greatly reduces evaporation.

As a result, you can water less often, and the water you do apply soaks in rather than running off or evaporating. Mulch also prevents heavy rain from compacting the surface and forming a hard crust, so more rainfall reaches the root zone. Over a season, this can make a noticeable difference to both your water bill and your rainwater tank.

It suppresses weeds

Most weed seeds need light to germinate, and a thick layer of mulch blocks much of it. Fewer seeds sprout, and those that do break through tend to be weaker and easier to remove because the soil beneath stays soft and moist.

Common garden weeds such as bindii and onion weed can take hours to control by hand. While mulch won't eliminate weeds entirely, it will considerably reduce the time and effort spent on weeding.

It regulates soil temperature

On a 40 degree day, the top few centimetres of bare soil can become hot enough to damage shallow roots. Mulch acts as insulation, keeping the soil considerably cooler through summer and reducing heat stress on your plants.

The same insulating effect helps in winter. In cooler regions such as the Blue Mountains, the South Coast and Canberra, mulch helps retain warmth in the soil and offers some protection against frost.

It improves soil health

Organic mulches such as sugar cane gradually break down, adding organic matter to the soil. This improves the structure of sandy soils so they retain more moisture, and helps open up heavy clay soils so roots can grow more freely.

Mulch also encourages earthworms, which thrive in the cool, moist conditions it creates. As they work the mulch into the soil, they improve aeration and leave behind nutrient rich castings. A healthy, active soil supports stronger plants that are better able to resist pests and disease.

Choosing and applying mulch

The best mulch depends on what you are growing:

• Vegetable gardens: sugar cane, pea straw or lucerne. These break down quickly and enrich the soil, so they should be topped up each season.

• Garden beds and shrubs: Forest mulch, eucy or pine mulch, which last longer and give a neat finish.

• Native plants: coarse woodchip or leaf litter. Avoid nutrient rich mulches around phosphorus sensitive plants such as grevilleas and banksias.

• Succulents and dry gardens: gravel or pebbles, which keep the base of each plant dry.

When applying mulch:

• Water the bed thoroughly first, then spread the mulch over moist soil.

• Apply it 5 to 7 centimetres deep. A thinner layer allows weeds through, while a thicker one can stop water reaching the soil.

• Keep mulch a hand's width away from stems and trunks to prevent rot.

• Spring is an ideal time to mulch, before the summer heat arrives.

A small effort with lasting rewards

With summer approaching, now is the perfect time to visit your local garden centre or even reach out to us and we can help mulch your beds. It is an afternoon's work that will benefit your garden for months. Your plants will be healthier, your soil will improve, and you'll spend less time watering and weeding.

Happy gardening!