Rubber Mulch vs Wood Mulch – Are These Your Only Two Choices?

It’s the easiest thing to do for healthier plants and soil, reduced water use and far less garden maintenance. Your plants will love you, it’s easy to do and it can be very cheap…what is it? Mulching!

With all of those reasons, it’s hard to understand why more people aren’t doing it. Mulching is the process of using an additional porous layer of material to cover your garden beds. There are two basic types of mulch, organic and inorganic. But you will see, that the choice is wider than just rubber mulch vs wood mulch!

How to Use Your Mulch

Organic mulch

Any material that breaks down and adds nutrients and organic matter to the soil as it decays such as bark chips. Depending on the type that you use, organic covers need to be either replaced or replenished on a regular basis.

Organic mulch can be laid with or without a barrier or mat between the soil and the mulch. By adding a permanent mat you will restrict the transfer of decaying matter into the soil causing new ‘soil’ to form on top of the mat. When you are spreading the mulch onto your garden bed, it needs to be spread to a depth of around 50 – 90 mm for the best coverage.

Inorganic mulch

This is any material that remains relatively the same and doesn’t show any noticeably break down such as rubber. This type of mulch doesn’t contribute to soil quality or fertility.

Inorganic mulch is recommended in high bush fire risk areas so make sure you take that into consideration when making your choice! It also only requires a general tidying up and annual topping up rather than total replenishment or replacement.

You will need to lay it with a barrier or mat between the soil and the mulch because the weight of most types will make it likely to sink into the soil. When you are spreading this type of mulch onto your garden bed, it needs to be spread to a depth of around 50 – 90 mm for the best coverage.

Each choice has its own benefits and appropriate uses. Their life spans also differ and will have an impact on which one you choose. The following list shows the general life span of the various mulches, these can vary depending on the climate you live in and how much weather your mulch is exposed to.

Types of Mulch

Organic mulch

Coir or coco block: This is a by-product of the coconut industry, this organic mulch comes as compressed blocks or bricks of coconut fibre and chunks. They expand in water, ready to spread around plants. Buy it by the block on in brick form.

Advantages: It is convenient and boosts the soil

Life span: 12 to 18 months

Leaf litter

This is often called the Tree Loppers blend, it is an uncomposted mix of leaves, twigs and shredded branches. You can buy it in bulk by the cubic meter.

Advantages: It is cheap, light and easy to spread

Life span: Up to 18 months

Composted mulch

This dark colored mix of fine and coarse material contains recycled green waste that has been composted and is bought in bulk by the cubic meter.

Advantages: It has a reduced nitrogen drawdown and easy to spread

Life span: Up to 18 months

Pine bark

Uncomposted pine bark is graded into sizes and sold shredded, chipped or in nuggets. You can buy it in bulk by the cubic meter, or bagged.

Advantages: It is cheap, light and easy to spread

Life span: Up to 18 months, longer for big nuggets

Lucerne straw or chaff

Finely graded weed free straw is highly recommended for rose gardens and vegetable beds. You can buy it by the bag or in the bale. Pea straw is an alternative to consider.

Advantages: It is lightweight, boosts soil and adds nitrogen.

Life span: Up to 12 months

Eco Cover

Made from recycled paper products, this clever mulch underlay is 100 percent biodegradeable. It is sold by the roll and one roll covers 4 square meters.

Advantages: It suppresses weeds and adds organic matter to the soil.

Life span: Up to 12 months

Inorganic Mulch

Decorative pebbles

Natural and quarried pebbles and gravel are sold in a range of sizes, polished finishes and decorative colors to suit any designer look you want. It is sold by the tonne or in bags.

Advantages: Different graded sizes and colors are available

Lise span: More than 18 months

Scoria

A rich ochre colored volcanic pebble, it’s a good lightweight substitute for gravels like Riverina Red and it looks great in a succulent garden. You can buy it by the tonne or bag.

Advantages: It comes in different graded sizes and is much lighter than most gravels.

Life span: More than 18 months

Colored pebbles

This is available in a range of natural and enhanced colors, including some very flambouyant options! It is sold by the bag.

Advantages: Fantastic designer color ranges available

Life span: More than 18 months

Re-Ag

A recycled aggregate of crushed and graded stone, cement and tile, it can also be used for paths and is bought by the tonne.

Advantages: Different graded sizes are available and it is a recycled product.

Life span: More than 18 months

Perma Mulch range

Made from recycled rubber in colors and textures that resemble classic (organic) mulches. It is bought by the bag.

Advantages: It is durable, recycled and is available in designer colors.

Life span: More than 18 months

There is so much more available in the search for a good mulch than the traditional rubber mulch vs wood mulch argument would have you believe!

If you don’t have a nursery close to your or your only nursery has a very limited range, try searching on the internet for a company that will deliver the type and quantity that you would like for your garden. The cost may not be as much as you would expect.