Nursery a well-kept secret in the Garden City

Christchurch is well known for its parks filled with established trees. What's more of a secret is that many of these huge specimens started their lives as seedlings in a Council-run nursery in Harewood.

Christchurch City Council's Harewood Nursery grows thousands of shrubs, trees and other plants used in city parks, street landscaping, and the regeneration of native bush on the Port Hills and wetland areas.

It was established in 1978 and for the past 38 years a small team of Council staff have been quietly collecting seeds, propagating cuttings, and nursing trees into the mature specimens that people enjoy around Christchurch. The red maples that will be a major feature of the Earthquake Memorial Park are being looked after at the nursery until they are ready to be moved to their permanent home.

The nursery is not open to the public, but it houses an impressive selection of plants stretching over 11 hectares including native grasses, astelias, magnolias, heritage fruit trees, upright oaks, red oaks, pin oaks, hornbeams, field maples and Turkish tree hazels.

"We grow what the Council's landscapers want us to grow basically, and we try and keep up with it," says Council Nursery Supervisor Joe Cartman who has been at the nursery since it first opened - long enough to recognise many of the older trees in parks around the city as ones that he helped grow from seedlings.

Trucks regularly deliver loads of potting mix - about 9 cubic metres at a time - to the nursery to be used in potting up trees and plants. The nursery is busier now than it was before the 2010 earthquake, Mr Cartman says, with the rebuild bringing extra demand for trees, as well as landscaping and revegetation plants. In the 12 months to June the nursery dispatched 1600 specimen trees and 240,000 smaller grade plants.

In an oversized garden shed, there's a fridge full of seeds that nursery staff have collected from local native trees, including a stand of about 30 pre-European totara on the Port Hills, and pittosporum, matai and kahikatea trees in Riccarton Bush. The harvest has just finished and sitting in saucers on a bench for sorting and drying there are golden kowhai seeds, bags of hazelnuts and kanuka and pittosporum seeds.

Kowhai seeds collected by nursery staff

Nursery worker Mike Smith says the idea behind an in-house Council nursery is that it provides good quality trees and other plants at lower cost than a commercial nursery would charge. Nursery workers collect seeds from natives themselves rather than relying on commercial sources so they know the seeds is genuinely local and suited to the local climate and soil type. "A lot of the seeds you just can't buy commercially anyway."

Not all of the trees and plants are grown from seed, some are sourced from commercial nurseries and a state of the art propagation greenhouse, built three years ago, houses thousands of plants grown from cuttings. They are kept at 20 degrees and sprayed with a mist of water at regular intervals. Griselinia, spinifex and many other plants are flourishing under the protection of a double-skinned plastic roof.

The nursery has a farm-like atmosphere, with roaming chickens, flocks of quail and native birds in the trees. "We try and work in with nature as much as we can around here," Mr Smith says. "It's a very balanced environment, there's a huge amount of birdlife and that is very beneficial for growing trees."