Canterbury
Who says you can't grow avocados in a snow zone? All you need is patience, a paintbrush, a pillow of frost cloth – and a plastichouse.
Dawn Coberger’s long avocado quest.
I’m not one to shy away from a gourmet gardening challenge. My tunnelhouse tomato crop of 160 varieties followed a flippant bet with a fellow chef, and my eggplant harvest featured in NZ Gardener in October 2020, after Lynda Hallinan challenged me to grow a wheelbarrowful of these finicky fruit.
So when I was told you can’t grow avocados here in Canterbury, I dug my heels in – and dug over the raised beds in my Hororata tunnelhouse, which measures 30m long and 10m wide – and impulse bought four miniature grafted varieties from avopro.co.nz. This nursery has been experimenting with grafting dwarf avocado trees since 2000.
I chose ‘Hass‘, ‘Bacon‘, ‘Zutano‘ and ‘Reed‘ and, in April 2018 my babies were bedded into their forever home.
Gardeners in the milder north might not appreciate my climate –
and what a tough ask it is just to keep an avocado tree alive here on the Canterbury Plains, let alone get it to fruit at 190m above sea level. The trees won’t tolerate frost when young and they hate wet, cold feet, but in winter and occasionally spring, snow can settle on the ground around my tunnelhouse. They also require a perfect pH of 6.3-6.8, plus well-drained soil (plant on a mound if your soil is too heavy) and wind protection. Be very careful not to disturb their tap root when transplanting.
A balanced diet and bucket loads of love seem the key to getting an avocado tree to flourish. I dote on my four trees day and night. In winter I shroud them in a Barbie dream bed of draped frost cloth, because even inside my tunnelhouse the mercury dips below zero. I’ve installed a hanging mechanic’s lamp over each wrapped tree to keep them snuggly and warm, and run a fan on a timer to ensure the air doesn’t freeze, even on the night when we had a -10ºC frost which burst the water pipes!
In an open garden setting, avocado trees can grow to 12m tall, so careful pruning in May is required to keep the fruit at a pickable height, but Avopro’s trees are designed to keep their heads down.
Avocado trees flower abundantly.
My baby trees produced so many flowers that I reluctantly decided to prune most of the buds off from the first flowering, so as not to stress the young trees. The male and female flowers open at different times of the day and are insect-pollinated.
Rather than leave pollination to chance (or to mother nature), I hand-pollinated the flowers on one side of each tree to see if I could do a better job. I was out there at least twice a day to capture pollen on my paintbrush from the male bits to transfer to the female flowers.
It was worth the effort, as only my hand-pollinated flowers set fruit.
One of those precious fruit, a thinskinned ‘Zutano‘, held on, starting to swell in December 2019. I spent the next 11 months patiently (actually, not at all patiently) visiting my solitary fruit each day to check its readiness.
When avocados are ready to harvest,
a gentle tug is all that’s needed to remove the fruit from the tree with its stalk still attached. At the end of October, I took the plunge, pulled my precious fruit off the branch and brought it indoors to finish ripening on my kitchen bench.
The stress of waiting for the perfect moment to cut it open nearly did me in, but after five days the stalk had fallen off, the skin had dulled and the flesh had noticeably softened.
I grabbed a knife and sliced it open. Success! It was rich and creamy in texture and so much more flavoursome than any storebought fruit I’ve eaten.
Non-gardeners may think this labour of love was a little over the top. However, we all know homegrown always tastes better than what you buy – and my miracle avocado was no exception.
Speaking of miracles, although my ‘Zutano‘ tree is now taking a wellearned break from fruiting this season,
I’m delighted to report that there are 68 fruit (yes, I counted them all) slowly starting to swell up on my other three trees. They might not all turn out to be viable, but here’s hoping I’ll never need to buy avocados again.