June 2013

Feijoa ‘Tagan’ 3 years on from the nursery. Any cool temperate city has an abundance of great spots where we can make use of a warm temperate/subtropical micro climate. In this part of the garden the cold southerly misses overhead, we increased sun reflection by painting the upper wall white and the neighbours bedrooms radiate heat to minimize nighttime cooling. Just a couple of fruit left after a bumper crop.
Avocado seedling volunteering under a feijoa. I’m not sure about the future for this one! Hardy enough for Dunedin winters but fruiting is probably unlikely for now. In our lifetimes I expect we may see a season every now and then which could get the job done. Unfortunately, rather than simply an easy progression to a warmer climate, Dunedin (and elsewhere) should expect unpredictability and crop challenges as a result of climate change. Our eggs need to be in as many baskets as possible. Hence the avocado!
After witnessing the success of feijoas in the backyard I decided last spring to plant a feijoa ‘unique’ hedge bordering the footpath. Aside from fruit this will provide an evergreen screen to gently enclose our courtyard, nectar for birds and bees, summertime afternoon shade for strawberries and a more beautiful view from inside. At the time of planting I scattered hulless black barley, tick beans and sicilian rocket under a thick mulch of linseed straw and large sticks. During the season I chopped and laid the underplanting around the feijoas where necessary. Otherwise the crops were left to seed for us to collect, broadcast and use as mulch in place. Early summer cuts of the barley re-sprouted easily.
With hindsight, one of the first actions in this garden should have been to create sturdy trellis on all suitable walls (neighbours walls included). 2 years ago I (mostly) completed it and shuffled a few plants accordingly. So many species are suited to the two dimensions and become very easy to harvest and maintain. Some may need the increased shelter/light/warmth to thrive. Our high walls are home to climbing beans, boysenberries, fan-trained peach, grapes, espaliered mulberry, kiwifruit and hardy kiwi, tomatoes, goji berries. Shadier trellis houses redcurrants, blackberries and elderberries. Gooseberries are also well suited to a partially shaded espalier.
Vigorous climbing beans (especially scarlet runner beans) are a standout crop for us. They grow back each year on cue with rising late spring temperatures and provide a relentless supply of fresh beans and more importantly, a generous supply of protein (stored dried beans) for the winter. In summer, we eat what we can reach fresh and what we can’t is left to dry on the upper vines. Because the pods dry very straight and vertically, the beans are quite safe from mould after summer and autumn rains (as opposed to broad beans). I sometimes miss a few but find them safe and sound the following spring. When the plants die back (or when you cut them) they can release nitrogen to the soil and plants around them via a bacterial root association that converts atmospheric nitrogen N2 into ammonia NH3. Most legumes (beans, peas, kowhai etc) and some other plants have these symbiotic nitrogen-fixing bacteria. Nitrogen and carbon are 2 fundamental soil elements that we can harvest from the atmosphere with the right soil management strategies. In the case of carbon this is often called ‘carbon sequestration’, which is exactly what we need to have happening on the balance globally to mitigate and reverse rising CO2 levels. Unfortunately, most of chemical and organic agriculture is a net contributor to atmospheric CO2 through frequent tillage which destroys soil carbon, releasing it to the atmosphere, thereafter increasing ┬ádependence on artificial fertilisers and organic inputs. We need a permaculture (permanent agriculture) that can rebuild soil carbon and provide ecosystem function whilst providing for our needs. This means building systems that mimic natural functions such as plant succession (through time) and plant stacking (in space).

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