Now you may be expecting me to talk about low maintenance plants, efficient
water use, maybe even ground breaking landscaping practices – but I’m not.
Quite simply none of that matters, unless you get the most important crux of
all your gardens success right. What I’m talking about is soil.
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Listen in closely. You’re missing the most crucial key to gardening success.
You’ve likely never been told about it, everyone’s heard about mulch, water
wise irrigation and planting the right plants. But almost no one talks about
soil texture.
Water repellent, dry dusty SAND. That’s your problem. The fix is easy
though, when you know some basic soil science. Here in Perth we have just that
– SAND. Our “soil” has no clay or silt, and because of that all of the precious
organic matter we keep adding just blows away in the wind. There is nothing
there to hold onto it – no silts or clays.
Thankfully sand is the easiest of soils to work with. It’s much easier to
add clay and silt to sand than it is sand to clay based soils. Another great
thing about sandy soils is that because they are so loose, they almost never have
any excesses – with the exception of calcium, if the soil has limestone in it;
or sodium if the water we are irrigating with is salty, which most of our older
Perth bores are.
Being so open and leachable isn’t a good thing though because ALL of the nutrients
are leeched out of the soil, not just the excesses. Which means we need more fertilizer
and our plants need more specialized care.
Clay, clay, clay! Add it to your sandy garden soils. The best clay I’ve used
is Kaolin clay, followed closely by its very similar cousin bentonite. Both
clays will permanently change your sandy soil to dark rich loams that will
build in fertility year upon year - without much input from you.
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The best builders of soils are plants, a story for another article. But you
need to start the process by balancing your soil first and foremost with the
correct amount of clays and silts.
For vegetable gardens and tropical gardens which have plants that demand
deeply fertile soils I recommend mixing in 10-15kg of clay per m2 – don’t go
over 25kg though, or you’ll end up with gluggy, wet clayey soil.
For Mediterranean and exotic gardens (roses, perennials etc) aim for 7-10kg
per m2. And for native gardens adding just 5-7kg per m2 will be enough to
change your water repellent dusty soils into free draining, water absorbent
goldmines for natives.
Mix the ratio you choose into the top 30cm of the soil for new garden beds
or rake it into the top 15cm of soil around plants in established gardens.
Remember to always water the soil to help the clay bind to the sand and organic
matter – this will jump start the soil building process.
Finish the project with a 100-150mm layer of course wood
chip mulch and within 6 months you’ll have the richest soil for Garden Services in Perth.
You can then grow anything to your heart’s desire without a worry.
