Growing your own food garden is a cost-effective way to increase your vegetable and fruit intake. Photo/ 123rf
Growing your own food garden is a cost-effective way to increase your vegetable and fruit intake. Photo/ 123rf
Gardener Claire Mummery gives expert advice on how to create your own healthy soil for growing and harvesting edible crops.
With soil quality at an all-time low, soaring prices and less space to grow food than ever before, it is vital we find a successful method to create our ownfood gardens.
For convenience, most people buy a kit set or build their own raised bed and proceed to fill it all with potting mix or compost. Not only is this extremely expensive, but it can also create a range of problems, including a regular need to replenish compacted soil that water cannot penetrate, and stunted plant growth.
Most bought mixes contain a limited amount of plant-available food, which is rapidly consumed by growing plants, leaving the soil depleted of the essential nourishment they need to flourish. The soil then quickly compacts and the plants' roots struggle, weakening their health. The mix just becomes worthless, except for the bulk it gives you in the bed.
Whether in raised beds, pots or balcony gardens, I have cultivated a formula for growing abundant, nutrient-dense food with minimal financial cost. The method has been shaped over more than two decades and gives me exceptional food all season long - and the secret is in layering.
By layering your garden beds with a mixture of carbon, nitrogen and essential minerals, your plants will have enough food to set them up for a summer of success. This creates solid foundations for them going forward too because it's like a mini compost, jam-packed with nutrients.
Step one - drainage
The construction of your beds is important. If your bed is deeper than 45cm and you have access to rotten rock, this makes a great bottom layer. In the bottom of pots, add sticks, twigs and stones to enable good drainage.
The bottom of any growing bed must have a layer of carbon, either sitting atop the drainage layer if you have one or directly on top of the soil if not. I lay thick overlapping cardboard on the soil as this encourages worms to come up, which is so valuable.
On top of this, I lay sticks and small branches. These are broken down over time by fungi, beneficial bacteria and worms, steadily releasing essential nutrients for the plants' roots to uptake.
On top of the wood, I add a thin layer of leaves to fill in any gaps. Make sure the leaves are well-stuffed into the corners and around all edges of the bed to prevent the water from escaping in the summer months.
To give it an extra kick of potency, I water the entire bed at this stage with my diluted bokashi liquid (a by-product of the fermented food composting method I use) or worm juice (liquid produced from a worm farm).
Top tip - If you don't have these available, make sure you still diligently water each layer as you build the bed, to ensure it is truly moist before the hot, dry weather arrives. The key to summer success is adding the moisture while you build the bed and then simply retaining it all summer long with excellent mulching!
Compost is a key factor in creating a nutrient-rich soil for your food garden. Photo 123rf
Step three - nitrogen
Our next layer requires a source of nitrogen, which can be animal manure, grass clippings, bokashi or well-rotted compost.
I personally put my bokashi (fermented food waste) on this layer, as it provides food for the established roots later on in the season, and I have found this to be remarkably successful.
The nitrogen layer should be much thinner than the carbon layer, especially when using grass clippings, which turn slimy when added too thickly, or can heat up so much they burn the plant roots.
If you have enough diluted bokashi juice or worm juice, I recommend you water every layer with it, as this really creates the magic.
Step four - continue your alternating layers
Repeat this process, alternating between carbon and nitrogen, until your bed is two-thirds full. I then spread a 3cm-deep layer of potting mix and topsoil, and leave the bed for a week to settle, before planting seedlings or seeds straight into it.
I fill the remaining third right before summer starts with a thin nitrogen layer and a robust mulch, to keep the soil from drying out over the hot months.
Step five - enjoy a summer of abundant nutrient-dense food you have grown
This method has been very successful for me. By the end of the growing season, your bed should only need a small top-up to replenish the layers that have broken down, and be ready to go again the following season! Give it a try to see for yourself.
For more gardening advice, visit growinspired.co.nz
