Planting & Budgeting Calculator

Planting site area

On the ground, you can measure the area of the site you want to plant using a long (50m) tape measure, a measuring wheel, or by simply stepping it out. For the last method you can calibrate your normal step by walking a known distance (e.g. 100m rugby pitch), counting your steps and dividing the number of steps (e.g. 143) by the known distance which gives you your normal step length (143/100 = 0.7m). Multiply the width of the site in metres by the length of the site in metres to get the area in square metres.

Alternatively you can use Google Maps to draw a polygon around your planting site and it will automatically calculate the area.

Plant spacing

Your choice of spacing will vary depending on your site, how quickly you want the site covered in native vegetation, the species selected and grade of plants from the nursery, and how many plants you can afford to plant. The choice of planting pattern and density is a balance between planting at a dense spacing to achieve canopy cover and hence weed control quickly, and wider spacing requiring a commitment to weed control over longer timeframes. For more information on spacing refer to this PDF document.

You can either enter average plant spacing or plants per ha – each will be calculated from the other.

Ratio of shrub to tree species

Many of our native tree species will benefit from the shelter provided by surrounding nurse cover vegetation typically comprising a range of hardy shrub hardwood species. Planting that mimics natural succession processes by establishing a nurse shrub cover is often more successful than planting only tree species, especially on harder exposed sites. A higher ratio of shrub to tree species is recommended taking advantage of often lower cost for nursery-raised seedlings of shrubs and their fast growth that will give rapid canopy cover to suppress weed growth.

The calculator is set at a default shrub to tree ratio of 3:1 (75% shrubs species to 25% tree species), but you can override this.
If you will be planting only shrubs enter a shrub to tree ratio of 1:0.
If you will be planting only trees enter a shrub to tree ratio of 0:1.

Select species

Selection of species will depend on your site characteristics. While some species occur nationwide, many have more restricted natural ranges so check out local websites and other information sources for which species are found in your region. If you need help to select which species to use on your site seek expert assistance from your local council or Department of Conservation office, or ask your local native plant nursery for advice.

Most planting programmes focus on only a few key hardy shrub hardwood and monocot species, and the main native conifer and hardwood tree species. Use the checkboxes to select from the most commonly planted species planted in restoration programmes. If you have other species to plant that are not included in the checkboxes then enter the plant names in the “Other Shrubs” or “Other Trees” fields, one per line. For plant names refer to the New Zealand Plant Conservation Network website.

Proportion of each species

You can elect to enter the approximate proportion of each species you want to plant on your site. The overall proportion of shrubs to trees that you have already selected (Step 3) will automatically govern the total proportion of shrubs vs trees. The total percentage of shrubs and trees must equal 100% or the numbers will not stack up.

Decide what proportion of each shrub and tree species you want to plant and enter the percentage numbers next to the species names.

Native seedling cost

Native shrubs: The bulk of most planting projects are planted in shrubs as a nurse shelter for a smaller proportion of interplanted native tree species. Most commonly used native shrubs used as a nurse species take one year to raise to a planting size seedling (e.g. 50cm high) and are cheaper than native tree species.

Native trees: Cost of native trees is usually higher than shrubs as most are slower growing and take at least 2 years to get to an often preferred planting size of 50cm high.

Prices for plants will vary from nursery to nursery depending on the species, height and size and grade of the container. Check out your local native plant nurseries and compare prices. It is recommended that you plant seedlings raised from locally sourced seed, so ask the nursery for eco-sourced plants from the local area. Enter the cost of each plant into the box next to each species box.

Delivery charge: If not picking up plants from the nursery there will be a delivery charge. This may be quoted at a per plant rate or as a cost for the whole order.

Site preparation cost

Grass spot-spraying: Most rural planting sites are recently retired pasture and many urban sites are dominated by grass. Where spot-spraying with herbicide is the preferred option based on expert advice, an approved spray contractor with accredited safety and skills along with appropriate equipment to undertake this work. A standard rate per spot including labour and chemicals may be an option on a per plant basis. Enter the per plant spot-spraying estimate, or quote for your whole site.

Extra vegetation clearing: If your planting site has exotic scrub species either as scattered plants or as a stand that dominates your site, you will need to factor in cost of clearing to allow planting of native trees. Obtain an estimate to clear your site and enter the cost below.

Planting cost

Smaller restoration projects can be planted by volunteer community groups and therefore the cost will be minimal or nil for planting. However, larger planting projects will require commercial contract planters where average cost per plant can be determined.

Enter the cost per plant for planting by contractor or leave blank if undertaken at no cost by volunteers. Alternatively you can enter a total planting cost for the site.

Planting consumables cost

Fertiliser: Incorporating fertiliser is not normally needed for planted native trees and shrubs on most sites other than on grossly nutrient-deficient soils or where topsoil has been scraped off or eroded away. Where fertiliser is used at planting this is usually in the form of a slow-release NPK tablet. Use label instructions to determine how many tablets are used per plant. Small plants usually have one tablet, larger plants 2 or 3 tablets. Enter the number of tablets to be added per plant and the cost per tablet.

Plant protectors: Artificial shelter can be effective on some sites to improve growing conditions of planted seedlings and reduce rabbit and hare browsing. A range of commercially produced plant guards are on the market including plastic corflute and biodegradable options made of hessian or cardboard. Protectors come in different heights for taller seedlings and there is the option of a mulch mat (e.g. coconut fibre) to insert on the inside of shield to prevent grass and weed growth competing with the planted native. Enter the cost per plant protector if used, and the proportion of plants that will have plant protectors.

Stakes: Stakes are only needed if plant protectors are not used. Where it may be difficult to find natives after planting a bamboo stake or similar inserted next to each seedling will save time during monitoring and maintenance. Bamboo stakes can be purchased in bulk from rural suppliers such as bundles of 500 to reduce unit cost. Enter the cost per stake if used, and the proportion of plants that will have stakes.

Mulch mats: If mulch mats are to be used and are not already included with tree protectors then enter the cost for a mulch mat per plant.

Other consumables: If you will be using any other consumables such as mulch or hydrogel then enter the estimated cost per plant for these. You can add a custom label for these consumables if needed.

Consumables cost for whole site: If you are not calculating the cost of consumables per plant you can add a total consumables cost for the whole site (optional).

Post-plant weed control costs

Newly planted natives will require at least 2 years of weed control depending on growth of natives and the type and vigour of weed species present that have the potential to overtop natives and reduce success of your planting project. Two weed control operations will be required for most sites in the first 12 months after planting and a minimum of 1 weed control operation in the second year.

It is difficult to estimate the cost of weed control as it will be site specific and there are herbicide spraying and hand releasing options to consider. In addition, landowners and community groups may choose to undertake weed control but other sites will require contractors. Default values for number of weed control operations per year and cost per plant is provided as a guide only. This can be overridden with a quote or estimate for your site. Alternatively, enter an estimated cost for the overall site. Longer term weed control can be costed on an overall site basis later in this calculator.

Fencing cost

This will vary from site to site where there are domestic grazing animals to be excluded from the planting site. A permanent minimum 8 wire fence is recommended but there are lower cost electric fence options that will require greater monitoring to ensure stock are not straying into your planting area.

You will need to work out how much fencing you require, or if existing fencing requires upgrading. Refer to existing fencing calculators available on websites of some regional councils such as:

• Planting and fencing waterways calculation sheet (Waikato Regional Council)
• Ministry for Primary Industries Stock Exclusion Costs Report

Enter the length of fencing in metres and the cost per metre of the fencing. You have the option of using Google Maps to draw the fence lines and automatically calculate the fencing length.

Alternatively you can enter a total fencing cost for the whole site.

Other site costs

Pest animal control: Where pest animals are present, a control programme is essential immediately before planting. Regular monitoring after planting will identify ongoing pest animal control required if planted natives are being browsed. Refer to regional council and DOC websites for information on pest animal control and obtain quotes from professional animal control operators. Enter the estimated costs for pre- and post-planting animal control where practical.

Long-term weed control: Weed control is necessary on most sites beyond the first two years but frequency and intensity will reduce as increasing numbers of planted natives successfully establish. This is site dependent so cost of prolonged post-plant weed control (beyond 2 years) is best done on an overall site basis. Most weed control is best done by contractors so there will be a cost. Enter the estimated cost for weed control across site for Year 3 onwards.