Benefits of using Mulch in the garden.

Let's take a look into mulch and why we use it.

From a horticulture point of view, we have three main reasons for why we use Mulch in the garden.

• Weed suppression. Having a good 50mm - 100mm base of mulch will hinder a large amount of weed seeds from viably germinating, as it usually wilts them before they have a chance to get any energy from sunlight.

• Moisture retention. This physical barrier reduces evaporation and gives the moisture a chance to penetrate the topsoil.

• Feeds the soil. As organic mulches break down over time, they release Carbon and Nitrogen into the soil, as well as other valuable micro-nutrients.

What we notice, in gardens with aged mulch, is a change in the soil structure. Here on Phillip Island, our main soil types are a heavy clay majority with some sandy areas. When this mulch interacts with the clay, it seems to break it down to make it more crumbly and much easier to work with. This modified soil structure, whilst also less dense, is much more capable of moving water through it, and therefore making nutrients more available via mass-flow. In our sandier areas, we find that the sand actually builds up valuable organic matter and that helps retain the moisture content.

Native Aged Mulch, supplied by Marc at Island Tree Care.

So, what's the best type of mulch to use? We are going to be very objective here and speak with soil and plant health in mind. With that being said, our number one choice every time is locally sourced and aged Native Mulch. However, from an aesthetics point of view, other mulches are perfectly to use if that is preferred. let's take a quick look into some options.

• Dyed Pine Mulches. These are more of a decorative feature made from long lasting pine chips with a black or red dye applied. They don't contain any fine particles so are a bit less messy but slower to break down and feed the soil.

• Pine Bark Mulch. Again, another long-lasting mulch consisting of more uniform, large pieces of Pine Bark. Whilst sold as a premium product, I find less soil integration and large gaps between the pieces allow weeds to grow through.

• Soft Fall Mulch. As the name suggests, this mulch is softer to fall on than other surfaces. It is produced to industry regulations to achieve this and therefore has a higher price tag attached to it. Its main uses are in playgrounds and settings where children are present, such as schools and camps.

• Native mulch. This is usually a mix of mostly native trees and unlike other varieties of mulch, it includes the shredded foliage too. When ages, these finer particles break down quickly to start a healthy biome within the mulch.

• Straw Mulches. These are usually used for a short-term cover and quickly supply the soil with extra nutrients. Great for use in vegetable gardens to feed the soil as the plant grows.

• Non-Organic Mulches. Crushed stone is a good method of weed suppression and also add a great aesthetic feature to a garden. These come in many varieties, from quarry toppings to larger (20mm+) stones or even river rocks or pebbles. Non-organic mulches would be the most expensive for the area.

Nice clean look with more Native Mulch.

At O'Brien Horticulture, we work in with local arborists to have access to what we believe to be the premium mulch. Whilst we prefer the aged mulch, we can also get fresh mulch dropped off, for a more cost-effective solution. We just need to ensure we keep this form of mulch away from the base of plants, as it can have negative effects whilst it ages. By sourcing local and aged mulch, we are helping to reduce our carbon footprint by engaging in this Circular Economy. Utilizing a valuable waste production from our local businesses helps to support them, as well as eliminating the transport costs and environmental impact to get it from who knows where.

In Summary.

Support local and get a premium quality aged, native Mulch. Your garden will love you for it in the end. That being said, personal preference for a different style is also fully supported.