Group Convenor: Ko Oishi

Northey Street City Farm is a three hectare permaculture community garden on the banks of Enoggera Creek in Windsor. The creek bank area is being regenerated with native species, including bush foods and cabinet timbers. Innovative methods are being used for planting in contaminated land.

The main section of the farm includes an organic market garden and kitchen garden, fruit orchards, chicken runs, a nursery, a weekend farmers’ market and a cafe. The farm hosts a number of annual events as well as a range of permaculture and horticulture training courses and visits by school groups.

For more information phone Ko Oishi on 07 3857 8775.

 

 

No-dig bushcare

Located on the Enoggera Creek floodplain at Windsor, Northey Street City Farm was founded in 1994 by a group of local residents who wanted space to grow their own food.

Once a mix-use district of housing and industry, the land was resumed because of constant flooding.

From a bare site in 1994 it has transformed into a farm growing edible plants, with a bush regeneration zone along the creek replanted with native species.

Fast forward 20 years and the bush regeneration site now has well-established trees, but it lacks native species in the understorey and groundcover which is dominated by weeds including Commelina benghalensis, Callisia repens and Dyschoriste depressa.

In addition to the challenge of establishing native ground cover when it is mostly shaded at ground level, the site is contaminated due to its past use by industry.

Recently, the Northey Street bush regeneration group led by Ko Oishi has been working with Brisbane City Council trialling a number of innovative no-dig bushcare techniques to establish understorey and groundcover. The group is recruiting a new volunteer coordinator, with the support of Habitat Brisbane and Bush Techniq.

No-dig site preparation

  • Mark out site.
  • Identify signs of natural succession.
  • Flag and stake native seedlings and plants.
  • Remove weeds with whipper snipper or hand sickle. The key to the success of the no-dig bush regeneration is to effectively remove the bulk of the above ground biomass.
  • First steam all weeds at the interface between the stem and the roots.
  • Second steam weed after a month.
  • Mulching with mature wood mulch – taking care not to smother recruitment of native species whilst mulching.

Planting techniques

  • Direct seeding – planned for future planting as part of the no-dig bush regeneration strategy in sections of the farm that are exposed, and with sufficient light availability.
  • Seed bombing – making balls of clay, sand, soil and seed stock for bombing when there’s plenty of water and sun to aid germination. Not yet trialled at the farm.
  • Surface layering of grass and herb cuttings with chicken wire to protect plants from vermin and brush turkeys.
  • Cardboard tube planting.
  • Hessian bag planting.
  • High flood risk bank plantings in 2017 – use of upstream stakes, coir logs and rolled or tied hessian bags to support thoroughly ‘tamped’ planted tubestock.

Planting outcomes

Surface layering of grass and herb cuttings with chicken wire to protect plants from vermin and brush turkeys: This could have been more successful if the wire had been kept on for longer or immediately replaced with heavy stick-stacks. Brush turkeys were likely responsible for their failure, as they looked healthy and established when the wire was removed, where on other sites this technique has proved successful.

Cardboard tube planting: Bladey grass Imperata cylindrica was recorded growing into the surrounding mulch through the cardboard tube planting after approximately seven months of planting. This may indicate that perhaps this planting technique is suitable for species that have moderately deep, rhizomatic roots, particularly grasses.

Hessian bag planting: The pH of the soil used may not have been correct for the failing species (probably too acidic). This has been the case in previous plantings on this site, where imported, composted soil was used. This is a factor to consider for future plantings. Species such as weeping basket grass Oplismenus aemulus and kangaroo grass Themeda triandra performed exceptionally well with this planting technique.

Whilst still in its preliminary phase, early establishment observations indicate that species such as Myoporum sp, and pigface Carpobrotus glaucescens may also perform well in hessian bag planting.

Maintenance and management of early plantings have been moderately intensive, with large branches and small logs placed around hessian bags to deter brush turkeys, and weekly watering for the first month, and up to two months for more exposed sites.

High flood risk bank plantings
2015-16:
Lomandra is well established on steep creek banks. Despite major flooding soon after the lomandra plantings, very few were lost. This could be attributed to early root establishment of Lomandra, and appropriate planting techniques.

Ko Oishi says it’s important when starting up a bush regeneration site, to identify areas of natural recruitment, and to establish ground and understorey cover as soon as possible, not just the canopy species.