October 2007 is the month that Tim Flannery, Australian of the Year, advised that in 2005 the concentration of CO2 equivalent in the atmosphere passed 450 ppm. Also this month a German study revealed that we passed Peak Oil in 2006.
I can think of few more momentous happenings for human civilisation. Certainly for human civilisation as we know it: 450ppm guarantees a minimum of 2˚C warming for our climate, which is at the upper end of what civilisation can adapt to. Seven years into the 21st century we are at the very brink of catastrophic Climate Change.
The resilience of life on Earth is not in doubt, but the resilience of life on Earth as we have known it is now highly questionable.
The last three gardening years have allowed Australians to experience what our climate will be permanently like in about twenty years time. We’ve lost the Murray Darling, which once provided 40% of our fresh fruit and vegetables. By 2030 we will have lost the Great Barrier Reef. Things could easily be harsher, but that depends on what we do globally to mitigate climate change.
The future will be shaped by what each of us chooses to do today.
So welcome to Brisbane’s New Summer – ‘Crematoria’. A mini-season that spans late September to early December.
After a wetter than average, greener than average late winter/ spring, the garden looked fabulous. Now the lawn is browning rapidly. The price of getting enough rain to fill the water tank was the loss of my maincrop of epicure potatoes. ‘Pink Eye’ and ‘Royal Purple’ tubers rotted unceremoniously as the tank over flowed – a little.
Crematoria is characterised by hot, dry winds, dust storms, extreme UV, cloudless skies, rainless thunderstorms – often sparking bushfires – and rising humidity. Caterpillars, grasshoppers, powdery mildew, nematodes, sap-sucking bugs and mosquitoes bring a sudden end to the easy growing conditions of the cool seasons.
Dewfall ceases to keep lawns green. Soil becomes parched and hard. Mulch starts flying in the wind. Crisped Bauhinia and poinciana leaves fall. It’s the worst time of year to attempt sowing and planting crops unless you have ample water. Mulberries are the stars of fruiting trees, bearing prolifically and offering respite for starving flying foxes.
Hot, dusty winds scour the landscape. Overnight these change the colour of the city with a film of rust-coloured dust. Dust from desertifying agricultural land to the west. Desiccating weather is great for seed saving, though. I’ve harvested pea, huauzontle, swinecress, mustard, rocket, dai gai choi and mizuna. Next week the Portuguese cabbage will be ready, coriander is flowering profusely, dill and red Russian kale are budding.
Our light frost in July set many things back. The neighbour’s black mulberry tree, which was fruiting heavily early last September during Sustainable House Day, had only hard, crunchy, flavourless immature fruit at the same time this spring. The white mulberry which I planted in our nature strip, is fruiting for the first time. Both types of mulberry are rapid growing shade trees, but black mulberries can be messy and weedy.
Brisbane’s new gardening seasons seem to be shaping up as:
Winter (June – July) – short, chilly nights, low humidity. Basically the same, but with intensifying continental weather there’s a greater risk of frost in formerly frost-free coastal gardens and East Coast Lows of rising frequency and intensity. With evaporation at its lowest, this is when gardening in Brisbane is at its easiest;
Spring (August – mid-September) – very short, cool nights, low humidity, desiccating winds. Azaleas have become Climate Change victims, flowering on near leafless sticks only to be singed by warm, dry winds in a few short days;
Crematoria (late September – November) – extends into former late spring. Hot, dry winds, dust storms, extreme UV, cloudless skies, rainless thunderstorms and rising humidity. Soil parched and mulch flying in the wind. Mulberries cropping, good for seed saving but heartbreaking for growing unless you have ample water to water frequently. The worst weeks for gardening here ;
Summer (December – February) – still variable but probably heavier rains more widely spaced with higher evaporation rates. This is the time when you’re thankful you put in an oversized tank to catch the rain when it falls for use in the extended drys.
Late summer (March – April) – cooler nights, decreasing humidity, shorter days. Fading hopes for useful rain. Drying winds return, singing the growth of exposed foliage of soft, tropical plants like Ceylon spinach. Parched soil. Hoping for rain so soil can be dug, composted, mulched and sown or planted for winter.
Autumn (May) – generally on one day sometime in May the humidity plummets for the last time. Take that as the cue to sow or plant winter crops.
Jobs for Crematoria:
A yellow patch of our lawn re-greened under 50% shadecloth over two days. Just in time to receive the footprints of a visit by ABC Radio and Organic Gardener magazine feature writer, Annette McFarlane and her TAFE sustainability students.
- Surround vegetable beds with straw or sugarcane bales, a defence against killer winds;
- Harvest and save seed;
- Mow lawns as high as possible. If this creates just a few lawn clippings, don’t use the grass catcher. Leave clippings to mulch the lawn against drought and to alleviate heat stress;
- Use 50% shadecloth to sun harden new seedlings and plants, especially if you are uncertain nursery-bought stock has been hardened prior to sale;
- Water compost heaps to keep them composting;
- Complete repotting, mulch and feed pot plants;
- Watch for caterpillar attack, checking plants twice weekly;
- Mulch bare soil and tree bases;
- Laying 50% shadecloth laid on a sunburned, water stressed lawn helps recovery.
- Regularly water trees – especially fruit trees, street trees and saplings. Plant trees following useful rain;
- Wear sun protection – eyes especially. Work in the shade or cool of morning and late afternoon;
- Grow more Aloe vera. A rescue remedy for sunburn… Oh, and another use for it is to alleviate the stinging bite of green ants of our tropical north
26th October 2007