A Close Shave With Frost During Ongoing Drought: Winter 2007

“What a lot of weather we’re having,” was something my Great Aunt Florence, a one-time Land Army girl, and someone as softly spoken as Lady Bracknell (of ‘The Importance of Being Ernest’) used to say. And we have had a lot of interesting, weather-related events.

In the Murray-Darling, irrigated horticulture usually provides 40% of Australia’s fresh fruit and vegetables, but production currently hangs by a thread. Macadamia plantations around Bundaberg are very thirsty, possibly under threat, and SE Queensland’s dairy industry is finding it hard to supply enough milk to meet state demand.

Shortly after bouncing back from Cyclone Larry, Queensland’s banana industry is currently producing just 40% of what it would normally be producing at this time of year due to the cold winter. And cold weather has claimed the Atherton Tableland potato crop.

Over the past month my garden received just over 40mm of rain and has since experienced five days of drying gales, sucking moisture from the soil and making the landscape look unusually tired. When that rain fell I lost my potato crop, just planted in the hot bed. Wet leaves and warm, calm conditions conspired to become potato blight. Spraying with copper hydroxide slowed the damage. A brief period of warm, wet wet weather culled a few sensitive succulents, including Stapeliads and a five year old Pachypodium lameri. I’ll miss that spiky totem. It had a brief, but happy life.

North Western Brisbane had brief showers, providing relief, but following winds stripped this moisture away as it did here. The soil is parched and much of the moisture left in bushland seems locked away, stored in vegetation.

My bananas are flowering, and that signals the end to the production of new leaves. The gales and chilly nights – around 6-8C –  have been stripping and burning their remaining leaves. I’m hoping enough will survive to help ‘power’ fruit production through to picking.

Three nights ago the curry leaf tree started browning slightly and curling its leaves in the cold, dry winds. I wetted the roots, having learned that this tree detests cold, wet foliage. A fungus attacked the leaves, many of which shattered and fell. This winter is the first time I thought this drought-hardy tree was looking seriously stressed. The bark started splitting and its crown started thinning.

At planting, in 2005, I watered it the routine six times. When ever I plant and tree or shrub, it gets watered to settle it in. This starts with watering twice in the first week. Then once a week for the next fortnight. The last two waterings come a fortnight apart. This is the first time I have watered since planting.

Last night the temperature dropped to 1.5C, the coldest night since moving to Brisbane in November 2003. Underneath the house, the overnight minimum was 6C, offering sufficient protection for cold-intolerant plants like orchids and seedlings. I put the most delicate into trays and carried them underneath the house, storing them overnight on a table. Hardier plants standing on my outdoor nursery tables are (so far) safe. They hold plants above the effects of a ground frost.

Around SE Qld, ongoing cold, dry conditions have reduced fruit set, and also reduced nectar and pollen production in flowering trees. Weakened by cold and lack of food and water, flying foxes are now foraging at ground level. Flying foxes are the most important plant pollinators in Australia. Many flying foxes have become desperately hungry. By climbing unusually low to grab a feed, they put themselves within reach of cats and dogs. Rescues of starving, injured flying foxes are rising.

In my garden, the sugar plum (Arenga pinnata) recently and unseasonably opened a brand new frond during the biting winds. It’s very pallid, a straw yellow colour. Last night’s ‘almost frost’ has blackened the tips of shoots and leaves on my golden sweet potato. Arrowroot and cocoyam leaves are, very gradually, revealing the extent of their cold damage.

Pawpaw leaves are crisped around the edges, their laminas are peppered white from cold. The Purple Osaka mustard are healthy, juicy and a rich purple colour. They need chilling to really colour well, just like Russian kale. Snow peas and broad beans are thriving.

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I planted Russian kale as well as Portuguese cabbage to hedge my bets. Kale for a cold winter, and Portuguese cabbage for an ordinary frost-free one.

Tonight I’ll cover the tomatoes, cabbage and sweet potato with net curtains and shade cloth. The tomatoes have miraculously escaped going that classic cold-induced blue colour which signals the end of their useful life.

Auntie Flo was right. Queensland has been having a lot of weather. And a lot of it is precisely what science has told us would happen. We are gardening in a continually surprising climate. It’s just the consequences of physics and chemistry.

Look beyond cyclones. Though dramatic, it’s worth learning to deal with tricky conditions and varied combinations (warm, calm/ cool, windy) that conspire to frustrate abundance.

In particular, watch out for weather alerts for East Coast Low weather systems. Plan for ten during the cool seasons, anticipate they can bring cyclonic winds, flooding rain, ripping gales and a following frost. I’m pleased I planted shelter to manage the wind tunnel between my home and a neighbouring house. Now they’re filling in, these coddle my cocoyams and bananas. These two are fundamental to household food security.

Jerry Coleby-Williams
!9th July 2007