The Te Mata Mushroom Company is based in Havelock North on the North Island, producing between 20-25 tonnes of fresh mushrooms a week, consistently throughout the year.

"Demand is higher in winter due to the reduced availability of other local vegetables and the increase in price of imported produce," owner Michael Whittaker said. "Commercially, mushrooms are grown indoors, so they are a year-round, non-seasonal product. Because mushrooms are non-seasonal, the shelf price is pretty stable."

The company, which began in 1967, only supplies the North Island domestic market and has no plans for export at this stage, producing both white and portobello (or brown) mushrooms. Mr Whittaker says they are grown in climate controlled rooms, so seasonal variation is minimal.

"Depending on the stage of growth, each variety can be sold as buttons (round, unopened mushrooms); cups (just starting to open) or flats (completely open). Each stage is useful for different recipes, portobellos tend to have a more robust flavour than whites."

However, because commercial mushrooms are grown indoors they may only see a very small amount of sunlight in their life cycle. But the company’s top product is the country's only Vitamin D mushrooms, which has a number of health benefits.

"We also introduced New Zealand’s first Vitamin D enhanced mushroom," Mr Whittaker said. “If exposed to sunlight mushrooms will naturally produce Vitamin D – even after picking. Our Vitamin D mushrooms are exposed to a special UV light before packing that allows them to produce large amounts of Vitamin D – a very topical issue at the moment, especially coming into winter.”

Te Mata's farm is one of the six remaining commercial mushroom farms nationwide, and provides a unique fully compostable tray and premium pre-pack products.