Mulching is important for plant health. For best results when mulching your fruit trees, adopt a rainforest-style approach.
The Ideal Environment
“Excuse me, which way to the forest?”
In which of the following natural environments do you think most plants would grow best?
A. In a sandy desert
B. In a lush rainforest
C. On the lawn in your backyard
If you answered A (Sandy Desert), then your plants might be a member of the succulent family eg. cactus. If you answered C (Backyard), then you must have very good soil to beat B (Rainforest).
Most plants choose to live in rainforests and for good reason. About 200,000 species of plants call the rainforest home. This is more than two thirds of the world’s plant species. And about 3000 of them bear edible fruits! If you want your plants to be happy and healthy, there is a good chance they will benefit from a rainforest style soil-building approach.
Rainforest Soil Ecology
Tropical rainforests have been churning out mulch since the dawn of time.
Have you visited a tropical rainforest recently? Have you noticed the abundant plant life? What happens under the canopy of a rainforest is simply amazing. For the diversity of life on the forest floor all contributes to a healthy soil ecology. Rainforest soils are teeming with macroscopic and microscopic life. Nobody ploughs, tends, waters, or fertilises the rainforest. Everything happens on auto-pilot. Insects, animals and microbiological life compete in an ongoing war for survival. And yet amidst this chaos of seemingly random natural events, plants flourish. It’s nature’s own plant nursery.
Nature’s Own Plant Nursery
The Australian Native Finger Lime fruit tree is a forest dweller that enjoys a heavy rainforest-style mulching.
Have you ever noticed a sick or dying tree in a rainforest? One that didn’t die from old age? If there ever was a fantastic approach to gardening, you needn’t look further than the rainforest. It’s a complete and awe-inspiring system.
Take the time to walk in a tropical rainforest. Bend down to the forest floor and notice the layers of dead leaves and what is underneath it. Living soil. Dark black and spongy. Full of humous and structure that holds onto nutrients while providing ideal drainage.
This dark black mulch is teeming with beneficial bacteria, fungi and microbes. And that’s how plants like it. The success of ancient trees that are millennia old is due to the ideal growing conditions in the forest. Magnificent fruit trees that sometimes grow to 20m in the rainforest often struggle to achieve even half that size in suburbia for lack of these perfect growing conditions.
How Does Mulch Work in Nature?
Forest trees create their own mulch every day.
Mulch is a natural product that’s been churned out by rainforests since the world began. Trees grow and shed their old leaves, bark and branches which fall to the ground. This material breaks down forming humous. Humous holds moisture and provides a breeding ground for beneficial bacteria and fungi which have been shown to increase plant health.
Small animals such as invertebrates find shelter amongst the fallen debris and their droppings naturally fertilise the soil. This provides a nitrogen boost which speeds up the rate of decomposition of the composted mulch and returns even more nutrients to the soil. Therefore, adding the mulch is just the start of the process, not the end goal. Composting is a great way to speed up this process and reach the end goal faster. In this way, more nutrients can be provided to your plants in a quicker timeframe. Moreover, compost provides a lot of the same benefits of mulch while keeping time on your side.
Benefits of Mulch
Mulch acts like a blanket covering that protects the soil underneath. It helps reduce the effects of erosion, and insulates against fluctuations in temperature. Plant roots prefer stable temperatures, as it assists in development of new adventitious roots (i.e. root growth). The benefits of mulching include:
- Regulates soil temperature
- Holds moisture and nutrients
- Contains ‘slow release’ nutrients that are released into the soil over time
- Protects soil from erosion
- Supresses weed growth
- Provides a home for beneficial organisms such as worms, fungi and microbes that support plant health
Getting Back to Basics
The gardening industry has seen many “silver bullet” gardening products come and go. There is always something new coming on the market that will “boost” your plants health. However, in many cases these are simply marketing ploys to encourage sales. If you are growing fruit trees, mulching is the tried and tested method. If you live in Brisbane (or any developed city of the world) you will have noticed the Council always places a load of mulch around street trees and parks trees. This is for good reason. Mulching is a standard horticultural practice and will extend the life of the tree.
Best Types of Mulch
The best types of mulch for your garden include:
- Wood chips (Cypress Mulch, Rainforest Blend)
- Barks (Pine Bark, Hoop Pine)
- Sugar Cane Mulch is great for vegetable gardens but can also be used around fruit trees
- Pine needles and pine cones can provide a more decorative look
- Recycled Mulch (after careful screening)
- Straw bales and Lucerne mulch
- Compost feeds the soil and holds moisture – Dual action!
- Mulches don’t have to be plant based. Pebbles, gravels, and stones can provide an attractive covering and insulate the soil.
Where to Buy Mulch
High quality mulch can be sourced from most garden centres. However, if you’re doing a lot and looking to save some money, free mulch is always available. For example, Moreton Bay Regional Council provides free mulch for residents (upon sighting your drivers license). This mulch must be carefully screened for small bits of plastic. Aside from that, it contains a lot of palm trees which breaks down fast and is excellent at retaining moisture. For this reason it makes a great soil conditioner and fruit tree mulch. You can pickup by the trailer-load so it’s great for covering a large area on a tight budget.
How to Apply Mulch
Wood chip mulch is great for fruit trees
As we approach the cold dry months of the year, it becomes most important to have a layer of mulch to hold water during dry winter weather. Even if you didn’t have time to follow any of my tips on How to Improve the Soil Before Planting, you can still reap the benefits of mulching. Simply throw a few buckets around the base of each tree you have planted. Apply the mulch to the surface about 10-20cm thick and out to the drip line (i.e. in line with the widest branches).
Do NOT:
Apply too thickly. The roots will grow up inside the mulch and then decay after the mulch dries out.
Dig the mulch into the soil. Wood chips and some barks will rob nitrogen from the soil and your plants growth may be stunted. The exception is when you are using non-woody or decayed material such as compost/straw which is fine to dig in.
Apply thickly around the trunk of the tree as that can promote collar rot.
When is the Best Time of Year to Mulch?
The best time to mulch is whenever it’s needed to replenish your garden beds. Mulch plays a useful role all year round. In summer, mulch keeps the soil temperature from getting too hot. In winter (which is our dry season), mulch prevents the soil from drying out too quickly. If you haven’t started mulching yet, the best time is now!
In Summary
With so many beautiful Queensland rainforests to enjoy, it’s hard not to be inspired by nature’s very own plant nursery. Many of our native trees produce wonderful “bush-tucker” fruits that are gaining in popularity. The rainforest environment is truly amazing. Most of our fruit trees originated from there. The home gardener would do well to observe and mimic this perfect environment. Get back to basics and cover your bare-looking garden soil with a winter blanket of rainforest mulch in combination with organic fertilisers. Your plants will think you are amazing.
