Garden beds

A garden bed is defined as a mulched area which may or may not have planting. 

It may also include densely planted areas which are not mulched i.e riparian zones.

All garden beds must be maintained in a weed free state.

Weeds are to be spot treated with herbicide or manually removed at each site maintenance visit.


Construction

  • Garden beds shall be excavated to a minimum depth of 300 millimetres.

  • Where possible, site topsoil should be stockpiled and used for the garden beds.

  • Subgrade within planting areas is to be ripped to a minimum depth of 150 millimetres and cultivated with gypsum.

  • The subsoil is to be graded and lightly compacted to re-establish a finished soil level of a minimum of 300 millimetres below paving level throughout. The soil is to be evenly compacted throughout to approximately 70% modified maximum dry density.

  • Supply and place 200 millimetres minimum depth of approved top soil to establish a finished grade that is 100 millimetres below paving and general levels throughout. Supply and place 75 millimetres depth of approved mulch.


Mulch

Mulch for all planting areas shall be weathered bark mulch. 80% of particles shall be in the size range 20-35 millimetres in plan, and 5-10 millimetres in thickness.

No particle is to exceed 50 millimetres. Mulch is to be stockpiled and thoroughly weathered prior to delivery to site. Mulch is to be free of weed material and seed, debris and foreign matter.

The Contractor shall spread a 75 millimetres thickness of approved mulch on all garden beds and 200 millimetres thickness of mulch on all trees in accordance with Council’s detailed specifications. The stems of all plants shall be kept free of mulch to protect the stem from possible rot.

NB:

  • All mulch used shall comply with the above requirements. When in doubt the Contractor should submit a sample to the Council Representative for approval, prior to delivery to site.

  • Mulch found to contain any recycled building materials (that is: chipboard, pine pallet etc.) will be rejected.


Planting

The Contractor shall be responsible for the handling and planting of all plants and in particular shall protect the root mass from all forms of damage during the planting operations.

All planting set outs shall conform to the endorsed landscape plans in specified densities, sizes and numbers. Any change to plant set out to be approved by the Site Superintendent and Council Representative.

  • Post hole diggers must not be used. The contractor must ensure there is no glazing of the sides of the holes as a result of the method of digging the hole. 'All hessian and other packaging material must be removed prior to planting.

Figure 2: Shrub and groundcover planting detail

Figure 2: Shrub and groundcover planting detail with table showing 5 points: 1 - specified shrub; 2 - excavate hole large enough to provide a 75mm-100mm clearance around the rootball. post hile diggers not to be used. backfull with approved topsoil. hole to be no deeper than the height of the rootball; 3 - top of rootball level with soil; 4 - 75mm depth approved mulch. mulch to be feaqthered away from stems; 5 - fertiliser to be mixed with backfilled soil around the rootball.
Click to Enlarge Image



Garden edging

Garden beds are to have edging in accordance with the endorsed landscape plan, edging shall be constructed to a standard that:

  • Clearly defines the extent of the garden bed.

  • Effectively retains mulch within garden beds.

  • Inhibits the encroachment of grasses and/or weeds from lawn areas into garden beds.


Timber edging

Figure 3: Timber edging detail

Figure 3: Timber edging detail

# Description
1 100 x 25 millimetres H4 treated pine edging.
2 Garden bed/path profile detailed elsewhere.
3 500 x 75 x 25 H4 treated pine pegs at 1.0 metre centres.

Note: Timber edging to be secured at 1.0m centres to pegs with galvanised screws. Pegs shall be 20millimetresbelow the top of the edging. Joints shall be made by bridging the abutting lengths with an additional section of edging set 20 millimetres below the top of the abutting lengths - peg shall be no more than 300 millimetres each side of the join.

Steel Metal edging may also be used instead of the standard timber edging. Check the manufacturer’s specification regarding installation.





Page last updated: Monday, 20 February 2017

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