Greendale Mushrooms


Kate, Geoff and fresh mushrooms destined for market.

Kate, Geoff and fresh mushrooms
destined for market.

Greendale Mushrooms is an established, rapidly growing mushroom farm set right of the heart of Canterbury, New Zealand. Located on the wide flat plains between the Southern Alps and the ocean, only half an hour from Christchurch city.

Owned and run by Geoff and Kate Clark, who bought the 10 year old mushroom farm in 2007. After extensive restructuring, some injection of funds, and countless hours of hard work, they have increased the production to 3 tonnes a week of white button mushrooms.

The whole process involved in the production of mushrooms is eco-friendly, and is one of the most renewable businesses you could find.

The mushrooms are housed in a complex of insulated growing rooms with regulated environments, growing in beds of compost made from the by-products of other industries. Summed up by Geoff “our whole operation uses the waste products of wheat straw and chicken litter to make compost. Then we grow mushrooms in it, and sell the finished compost to gardeners”. Indeed, after weeks of tightly controlled processes they develop compost which is perfect to grow fruitful crops of mushrooms, after this use the compost is sold to private gardeners and landscaping companies.

With the help of a team of local staff the mushrooms are picked, graded and packed in boxes everyday and trucked fresh from the property to nearby MG Produce market in Christchurch. From there the mushrooms are distributed to retailers, wholesalers and supermarkets mainly in the local Canterbury region.

More about our processes

Our business, Greendale Mushrooms, is a massive recycling operation.

The whole operation uses waste products of wheat straw and chicken litter to make compost. Then mushrooms are grown in it, and at the end of the cycle the waste compost is sold to gardeners.

We have owned the mushroom business. Based at Norwood on the north bank of the Selwyn River near Burnham, since June 2007. There is only one other commercial mushroom farm in the South Island and four in the North Island. Our white button mushrooms are sold South Island wide through MG (Market Gardeners Limited) to local supermarkets and wholesalers.

We have a great staff of eleven, including seven permanent part time harvesters who work when the mushrooms are ready to pick from the climate controlled growing rooms housed in our 1000 square metre growing shed. We consistently harvest between 2.5 and 3 tonnes per week all year round.

View of the compost preparation area with straw bales waiting to be

View of the compost preparation area with
straw bales waiting to be mulched.

A few boxes of mushrooms in a growing room ready to be

A few boxes of mushrooms in a growing room
ready to be harvested.

We make all our own compost–some 12 tonne per week; mixing up the wheat straw and chicken litter with gypsum and water, forming the compost into long lines called ricks.

In the first week the temperature inside the ricks goes up to around 70°C due to the exothermic composting procedure. The compost is then kept in a series of aerated bunkers for the next two weeks.

After that the compost is moved into a pasteurisation tunnel built from a re-purposed 40 foot refrigerated container where 60°C air is pumped through the compost to kill any undesired bacteria pathogens. The compost is then held at 50°C for a week. This conditions the compost which comes out of the tunnel black, friable and moist.

Wheat grains impregnated with mushroom spawn are seeded throughout the compost which fills specially made growing boxes. The mushroom mycelium then grows for two weeks through the compost. The compost is kept warm in rooms of 20 to 25°C with constant humidity and carbon dioxide levels to stimulate mycelium growth, before being cased with a peat layer.

The boxes then get transferred into a growing room where they are watered and then later fresh air is introduced to the room and the humidity and temperature are reduced. This induces the mycelium to form pins, which develop into mushrooms, the first of which are harvested 10 days later.

Four flushes of mushrooms are harvested from each growing room over a five week period, and after that the compost is steamed and sold off farm.

Then the boxes are refilled and the cycle is started again.

Greendale Mushrooms are part of the Commercial Mushroom Growers Federation, their website can be accessed at

Contact Details

169 Telegraph Rd.
RD 7
New Zealand
Phone: +64 3 325 4955