For those who like their walnuts pickled, the time to harvest them is midsummer, when the shells contained inside the green husk are still soft enough to pass a needle or knife through.
When picking and handling the green walnuts, be sure to wear gloves to stop your hands becoming covered in dark brown stain.
A poor crop and tip dieback on the branches, as apparent this year on some walnut trees in the Wakatipu, can be caused by bacterial blight, exacerbated by rain in spring at bud break.
To pickle walnuts, gather the nuts with soft shells and pass a sharp knife or knitting needle through each one several times, then place in a bowl and cover with brine.
To make the brine, mix cup of salt for every 5 cups of water. Cover the brined walnuts with a plate, weighted down to ensure the nuts are submerged, and leave in a cool place or the fridge for 5-6 days. Drain and cover again with fresh brine and leave for another 5-6 days.
Drain and spread the brined nuts out to dry in the sun for 2-3 days, turning occasionally, until they turn black.
Place the black walnuts in sterilised jars and cover with spiced vinegar, then leave for 2-3 months before using.
For the spiced vinegar, combine 5 cups white vinegar, 2 Tbsp peppercorns, 2 pieces of dried ginger and 2 Tbsp whole allspice. Bring to the boil and simmer for 10min. Cool and strain out the spices then pour over walnuts.
Delicious sliced on crackers in winter with strong pecorino or local Gibbston Balfour cheese, a hard-pressed sheep's cheese.
