The early gardener attracts the worms.
IF you want to rest easy with a comfy crop of home-grown vegies this summer, now’s the time to make your beds.
Helen Tuton, from Sustainable Gardening Australia, recommends backyard farmers pamper their soil. “Soil is just so important,” she says. “It’s the medium that feeds plants and gives them all the nutrients they need. Vegie patches are really hungry, because annual crops are very nutrient intensive.”
The first step is to clear the patch. Ms Tuton warns that we mustn’t be sentimental about our flagging winter crops. “People are always reluctant to pull them out, but you need to get ruthless,” she says.
Then, to prepare the soil for planting, aerate it lightly with a garden fork, add a layer of good organic compost and chook-poo fertiliser pellets, and mulch to a depth of about six centimetres. “If you don’t mulch, your compost and soil dries out and loses a bit of its vigour and vitality,” she says.
Water occasionally, but otherwise, leave the bed alone for a few weeks. “By the time you come to plant in September or October, it’ll be rich and full of worms,” Ms Tuton says. “If you’ve got good soil management practices in your vegie patch, 95 per cent of the hard work is done.”
Typically, Australian topsoils are shallow, clayey and ill-equipped for fast-growing annual crops. That means if you’re growing vegies, you can never add too much organic matter.
But to get the best results, it’s also worth taking a close look at the chemistry of your backyard, according to Adam Grubb from Very Edible Gardens (VEG).
“When you get the balance of the minerals in your soil right, your soil structure improves, your plants get a lot healthier and the food that you eat is more nutritionally dense,” he says.
VEG offers soil tests and interpretive reports with a focus on organic solutions, from $160.
Mr Grubb says there are three main soil types in suburban Melbourne (they change again when you reach the Dandenongs).
The eastern suburbs lie on ancient ground, grey-yellow clays dating from the Silurian period about 440 million years ago. “They tend to be leached, nutrient poor and have really bad structure,” he says.
All the soils he’s tested in the region have been lacking in calcium, boron and manganese – deficiencies remedied by adding lime (not dolomite), basalt rock dust and micro-nutrients.
The second area, south of the Monash Freeway and towards Frankston, has sandy soils that dry out quickly. For vegie gardens there, Mr Grubb prescribes regular applications of organic matter and mulch.
The third area, he says, is the volcanic plains that start in Northcote and go west, almost to South Australia. They’re the third-largest volcanic plains in the world.
“Volcanic soils are rich and much more nutritious. But the ones we have here are heavy clays, so you need to work in organic matter and calcium, like gypsum or lime.”
City soils can also sometimes bear pollutants, such as lead. “Where you’re near a major road or you’ve had flaking paint, there’s a potential for lead contamination,” Mr Grubb says.
Again, it’s always prudent to add organic matter, because well-composted soil reduces the lead uptake in plants. “There are some days I think compost can fix anything outside the marital bed,” he says.