Down at the Southport Joan Park Community Gardens last weekend, we hosted Mr Greg Plevey from Wormtec, a knowledgable and enthusiastic fellow keen as leafy mustard to share his ideas about maintaining optimum soil health for our gardens.
A shed-full of us gardening acolytes gathered, after enjoying the slurp and crumb of a few local household brewers and bakers, and settled in to what would become a fascinating chat about how to really create the space for wonderful food to grow.
It’s all about happy microbes! As gardeners we want to create and maintain an environment which allows these microbes to flourish. These are the parts of life that decompose our organic matter thus aerating the soil and providing food for the worms. They are the part in the equation that metabolises the compost and minerals we apply and convert them to living microbial humus yumminess.
There is an important aspect to ensure before this miraculous symbiosis can truly flourish. The pH of the soil needs to be just right. Neutrality is set at 7, but for the garden, we should be aiming for a soil pH of around 6.4. This is essentially a neutral environment, too acidic or too alkaline and the soil will simply ‘freeze’… I think this is when you just have DIRT.
So testing the pH of your soil is the essential first step in understanding your environment and knowing how to make the proper adjustments to get your soil to neutrality. To easily do this, use a high quality pH tester, the kind you buy for around $100, not the cheap as chips Bunnings kinds… these are not accurate enough and often give false readings, they’re just not worth the waste of time and money!
Greg went on to describe how you might go about adjusting the pH of your soil, for instance, using a hoop pine or tea tree mulch will balance out your highly alkaline soil as they are high in tannic acid. Likewise, adding ultra fine rock dust, lime, dolomite, etc. will lift your acidic soil to more neutral territory. The mulch we sell at the Gardens is organic sugar cane, which is neutral, so will not be affecting the current pH of the individual garden beds.
If the garden is too acidic or too alkaline, the soil ‘locks up’ and no microbial life processes can proceed. The conditions are not right and no matter how much fertiliser, water, sunshine or love you add to the soil, no microbial life processes will kick off. Greg used the analogy that when the fridge door is closed, there is no way to get to the food! Once the fridge door is opened, the microbes in the soil may benefit from the fertilisers, the composts, the organic matter that is added by solubilising what is there, gobbling it all up and creating the magical environment needed for plants to flourish. Balancing the soil is conditioning it, in order for the conditions to be right for microbial life to wake up and go about their business.
Likewise, if the soil of the garden is compacted, there is no space for life to happen. This anaerobic environment is just as debilitating for microbial life to flourish, and can be rectified by ploughing or tilling the soil, or indeed by “no dig” gardening methods, including applying the microbes directly, by through their million tiny actions, will ‘dig’ the dirt for you, aerating and turning, via their tiny processes. The knock-on effect is useful – roots can now travel down much much deeper, metres in many cases instead of millimetres and the plants have access to moister depths and less watering is required.
So, what are the microbes? Have a look at this webpage for some insight.
Have you been noticing that no matter how much you feed your garden, plant quality and yield still appears to be lacking? I have recently, and so my next step is to test the soil’s pH and determine which steps to take next to ‘unlock’ the potential for growing yummy food. I am currently growing a green manure crop in a section of my garden. This sprouting mixture of legumes, grains, vegetables and herbs will capture nitrogen from the atmosphere and when I turn it all back into the soil, will be transferred into the sub terrain to be broken down and released, thanks to the microbial life forms – hopefully whom will have ‘woken up’ by then! I will share a post on this process for you to see soon, once I have it completed.
I’ll end this post with a few bullet points taken from Greg’s talk. People had heaps of questions and there was a lot of discussion – I took down what was relevant and interesting to me… you might find the same, also!
~ Organic matter is essentially carbon = the building blocks of life
~ Horse manure straight from the farm and onto your garden will kill the worms! (Horses are given medicines which kill worms, without having composted the manure first, the toxins will still be present and be transferred to your garden). Be aware of this for ANY animal manure you place on your garden…
~ Kookaburra Worm Farms is the THE place to go…
~ When a plant is stressed (too wet, too dry, too hungry, too hot, not enough sun, etc…) it will emit pheromones that attract aphids/grasshoppers/other buggy nasties which *think* (and these next thoughts are mine) that the plant has begun to decay and decompose, they simply turn up on schedule as Nature has enlisted, to assist in this process. When we have healthy plants (by listening to their needs), the bugs don’t even register their presence in the garden and will ignore them.
~ Worms eat microbes, not organic matter!
~ No worms = no microbes = no soil fertility
~ Worm eggs can basically lay in the soil indefinitely and will hatch when moisture, temperature and food conditions are right
~ Worms’ skin is extremely sensitive. If handling earthworms, wet your hands first so the acid on your skin doesn’t burn them. When they wriggle wildly on your hand and bounce off, this is the reason why!
~ The more organic matter that is present in the soil, the higher the water retention