Mulching – what to use for mulch and why

When I think of mulching the garden I always think back to an autumn when one of my brothers and I did multiple trips filling the back of the ute with the trash left behind the harvester once the rice was harvested. It was scratchy and awkward work, but we knew how much Mum appreciated the gift of clean mulch. Rice straw was great because it was clean, had few weeds and because of the high silica content broke down very slowly. If only we had a baling implement for the tractor, we might have made some handy pocket money.

Today in our garden I use a variety of mulches. The type of mulch varies depending on the area in the garden I am planning to use it, the ultimate result I am hoping to achieve and also based on what I can get.

Every year I order 2 large round bales of straw which have been baled after harvest (usually a wheat or triticale crop) by a local farmer that he can deliver. I use this in the chook pen to create deep litter in the open pen and under the roost to catch the very moist droppings. This straw is nicely worked over by the chooks doing what they love best plus, when I clean out the chook pen I have virtually got the perfect mix to make hot compost (once all the scraps and straw from under the roost are mixed together). In Autumn I also add lots of large oak leaves to the pen, the chooks also break these into smaller particles. This makes the best base for a great compost.

I use this straw in other parts of the garden where I hope to add some softer organic material that will break down eg: under fruit trees, in the vegetable garden or new garden beds. The issue with this straw is there can be a high weed seed load of annual weeds, so I need to be prepared to keep on top of any weeds coming up.

Mulching under a grape vine with straw mulch to reduce weeds, keep in moisture and encourage worm activity under the top soil layer.

Mulching under a grape vine with straw mulch to reduce weeds, keep in moisture and encourage worm activity under the top soil layer.

Adding thick layers of straw to a  garden once the soil is nice and moist from rain or irrigation will help keep the moisture in the soil profile, can reduce weeds popping up and ultimately feeds the microorganisms in the soil as it begins to break down. This is not compost though so you aren’t adding nutrients – just food for the good soil community!

You do have to keep in mind that straw mulch is highly flammable so avoid using where you think this is an issue in our fire danger periods.

Straw like materials also include pea straw, Lucerne hay and sugar cane trash. All of these will help improve the soil and more importantly fuel the soil microorganism system. There are slight differences between each of the products with Lucrene hay generally container fewer weeds and higher nitrogen levels. Lucerne hay is usually more expensive so using it strategically where you really need an extra boost could be an option.

Mulching with wood chips in the areas dominated by native plants.I add what may be call wood chips or sometimes a forest mulch to the main bulk of our garden. These areas are dominated by native plants and trees. I have added so much of this over the time we have been here that I am starting to  make top soil. The advantages of this material for our garden (in these garden areas) include the much slower rate of decomposition. Loads of various sized woody material (diversity is the key here as this will also result in diversity of tiny critters involved in the decomposing process) plus finer leaf trash that also comes in the loads have help reduce weeds, kept in soil moisture when it has rained and provided endless hours of digger for the beautiful White Browed babblers that live in our garden. I do often feel a bit nervous in summer that we have a fuel load close to the house so am very careful just where I use this mulch.

Finally – given that it is Mulching with autumn leaves under fruit treesAutumn I have to mention how excited I get about the fallen leaves. These are such a gift each year. I love raking them up, putting them onto the garden beds knowing that all that deep goodness from the tree and deeply drawn up nutrients is cycling back to the earth to help the plants again for the next season. The leaves break down really quickly and are like a boost juice for the soil ..yep you guessed it..soil microorganisms (you will be sure to find worms in these piles). they are also free. I have been know to sweep urban streets collecting them.

Mulching also helps give your garden a nice tidy finish at times – a bit like adding a bit of definition. It is a great thing to do just before you display a garden or finish off a new area – maybe a bit like eyeliner?? For more information try the Sustainable Gardening Australia web site here.

Using mulch to help give the garden a complete and tidy look.

Using mulch to help give the garden a complete and tidy look.