Why Mulch? The benefits of mulching your garden in Perth.

Most of you savvy Perth gardeners know that mulching is good for your garden, but might not be so sure of the details in the why – and knowing the why behind the what is the key to choosing the right mulch for your plants and the best way to use it.

So, let’s talk mulch…

Why is mulching your garden in Perth so great?

• It helps keep the weeds down by stopping them from being able to germinate and develop to reach the surface of the earth for precious sunlight.
• Cools the soil by locking in moisture and protecting it from direct sunlight
• Protects feeder roots that grow near the surface from the heat and dryness of summer – especially great for us here in Perth!
• Reduces evaporation of water from the soil in hot weather, this is vital for keeping things green as well as reducing your water bills and watering frequency.
• Encourages soil organisms to thrive like our friends the worms, fungi, good bacteria and more.
• Reduces soil erosion from wind and water.

And finally – it looks good!

Much better than throwing down an ugly weed mat, it keeps things looking natural and earthy, can add some colour and, of course, is beneficial in all the above ways as well!

So now we are reminded of the reasons WHY to use it, let’s look at the HOW.

What makes a GOOD mulch for Perth Gardens?

The best mulches allow water to pass through and straight into the soil to be absorbed deep down beneath the surface. This way they don’t retain water and will dry out quickly, reducing the chance of rot and bacteria, and the soil will get the highest percentage of the water available. You can retain up to 70% of the moisture in your soil with a good mulch – an excellent investment in Perth summer!

The best mulches are made from:

• Chipped or shredded tree pruning’s – you can even use homemade to get rid of green waste and save money
• Crushed brick or gravel – doesn’t absorb water but will need a layer of weed mat underneath to prevent mixing into the soil
• Wood chips or pine bark – both to be used sparingly in exposed areas

Don’t use:

• Newspaper – quickly dries out and becomes water-repellent
• Lawn clippings – use for compost instead
• Products like mushroom compost, seaweed and animal manure – work great as soil conditioners if dug into soil before planting or under a layer of good mulch

Test your mulch:

1. Spread a layer of your chosen mulch 50mm thick over a metre of dry ground
2. Mix a little soil wetting agent into 9 litres of water and pour over your mulch
3. Leave for 1-2 hours and check – if the top of the soil and the mulch itself is dry, but the soil is wet to at least 10cm deep, then you have chosen well!

Tips:

• An effective mulching is at least 50-75mm thick, so no scrimping and saving! If it’s less, weeds can break through, if more, water will struggle to get through and make the mulch obsolete.
• Remember, organic mulches will naturally break down with time, so be sure to check regularly and top up when needed.
• Be careful not to place mulch tightly around the stems of plants, including shrubs and trees, as this can cause them to develop collar rot where the stem tissue is covered.
• If you have chosen a good mulch that lets the water pass through, you can apply fertilizer without removing the mulch layer.