Want a thriving garden? Start with your soil.
As with all living things, keeping soil healthy is an ongoing process, and this is especially important in productive gardens. As your plants grow, they remove nutrients from the soil, and these need to be replaced fairly regularly using composts and organic fertilisers.
Learn more about the soil type and rainfall in your local area
Caring for your soil
Healthy soil equals healthy plants. Soil needs organic matter such as mulch, composts and manure.
Worms break it down to make food for plants to use. Their burrows allow air into the soil so the plant roots can breathe. Organic matter needs to be replaced regularly as the worms eat it all up and plants absorb the nutrients. If organic matter is not added, the soil becomes like concrete in the summer and a sticky mess in the winter.
In addition, many people want a low maintenance garden. This is much easier if you look after your soil.
Here are some tips to get you started:
- Soil should be damp before you add mulch.
- Generally Spring is the best time to apply mulch, once winter rains have soaked in.
- Mulches made from recycled organics are an excellent choice as they save water, are long-lasting and feed the soil when they break down.
- Pea straw is a good option if you have not mulched the soil for a long time as it breaks down quickly, returning nutrients to the soil.
- When buying new soil for your garden, buy a soil that is mixed with recycled organics or compost. Don’t cultivate your soil unless it is very compacted after building works. Digging destroys the soil structure, which thereby destroys air holes and drainage spaces.
- When watering, use a trigger hose with a spray setting so as not to compact the soil as the water hits. The concentrated pressure of the water stream can close up valuable air spaces.
Potting mix versus garden soil
What is the difference between potting mix and gardening soil/topsoil? All soils are not created equal!
It may surprise you to know that potting mixes are manufactured and have very little soil or organic matter content.
Potting mix is specially blended to hold the correct amount of moisture in a container and provide a stable growing medium for pot plants. Potting mixes can, over time, become dry, worn out and begin to repel water. It is at this time that you can top up your pots with fresh organic material, like compost. This will add some much-needed vigour to the potting mix and help your potted plants thrive.
Garden soils and top soils are best mixed at least 50/50 with the native soil to maximise the performance of plants in outdoor planting beds. When used in a container, garden soils and top soils may stay too moist and promote root rot of your plants. They also have a tendency to shrink and pull away from the sides of the container when allowed to dry out too much.
Our heavy clay soils can become too heavy in the pot and can set like concrete. Potting soil used in an outdoor planting bed may be too well-draining and the bed could dry out too quickly. It also stops the water from moving freely through the garden, which will impact plant health.
Composting is an excellent way to recycle your kitchen scraps and garden waste. Compost transforms poor soil into productive soil and is a natural fertiliser for your plants. It also reduces your organic waste to landfill and saves you money!
How does composting work?
Well run composting systems need a balance of ingredients. The basic rules for building a composting heap is to have four essential ingredients:
- carbon (brown waste)
- nitrogen (green waste)
- air (oxygen)
Materials added in layers will start your compost off. Place nitrogen rich ingredients such as grass clippings or veggie scraps between carbon-rich ingredients such as dry leaf litter or shredded newspaper. Ensure the heap is moist but not wet and turn it regularly to include air.
What to put in your compost heap?
You can put the following things into your compost heap:
- kitchen scraps such as vegetable and fruit peelings, tea leaves and coffee grinds
- garden waste including autumn leaves, soft prunings and lawn clippings
- aged animal manures
- shredded newspapers, cardboard boxes or waste paper (not glossy)
- straw, vacuum cleaner dust and hair clippings can be added.
Did you know Victorians throw away the equivalent of one in every five bags of groceries they buy? Instead of sending your waste to landfill, why not consider starting your own worm farm?
Worms will ingest most kitchen scraps (but avoid meat, dairy, citrus fruit and onion), and provide you with an amazing fertiliser and reduce your greenhouse gas emissions.
What type of worm farm should you get?
There are many suitable containers for keeping worms, from ready made farms to basic wooden boxes or plastic stackable ones. If you are a ‘beginner’, polystyrene foam fruit boxes are ideal.
The most common composting worms are Indian Blues, Red Wrigglers and Tigers and you will find them at most garden centres typically being sold as ‘composting worms’. Or simply collect them from an active compost bin. Start with 1,000-2,000 to get your worm farm going.
In a couple of weeks, worm 'castings' will collect in the bottom of the top box, making a terrific fertiliser. Worm ‘wee’ or 'leachate' will collect in the bottom box.
Dilute the 'leachate' until it looks like weak 'tea', one part leachate to eight parts water in a nine litre watering can. This can be used as a plant fertiliser and is excellent for your veggie patch.
Every now and then you can collect worm “castings” from the top bin and scatter a walnut size ball into your pots where it acts as an excellent fertiliser.
To do this:
- tip over the top box onto a hard surface or pavement to expose the castings that have collected at the bottom of the box
- scrape off the crumbly castings but allow any worms exposed to wriggle back into the centre of the mound where the partially decomposed materials are
- if you find any worms have fallen out, return them immediately as composting worms will not survive in your garden beds or pots.