Potatoes grow best in well-conditioned, free-drained, fertile soils. The soil should not be prone to waterlogging and have good nutrient retention. We recommend soils with few stones - less than 5%.

Growing potatoes is suited to flat or gently rolling whenua. This is to help with the access and operation of machinery. We recommend 3-7 degrees to reduce the risk of erosion and to meet machinery requirements.

Potatoes need a soil depth of at least 60 cm (highly suited) and 45-60cm (suited) to grow well. Their shallow root system absorbs nutrients and water in the upper soil layers. We recommend other crops be grown in rotation and suggest a deeper soil than the rooting depth of 25 cm. 

For good potato growth and yields, various nutrients are required. This includes:

• Phosphorus - to stimulate root growth and increase tubers
• Potassium and sulphur - to contribute to the plant health and tuber quality
• Nitrogen - carefully managed to achieve high yields
• Boron, iron, magnesium, and zinc - in smaller quantities to produce premium tubers.

It's important to test your soils before planting your crop. Many companies offer this service. This will help you understand the current fertility of your block and nutrient requirements. Optimal soil pH is 5-7.5.

Soil safe Aotearoa

Potatoes are very sensitive to temperature extremes. They need mean daily temperatures between 18-20°C for optimum leaf and tuber production. Frost will kill potatoes, while temperatures higher than 30°C will affect the growth of the tubers.

Potatoes need an annual rainfall of between 500-700 mm during the growing season. Too much rain at any time of the growth cycle will affect the tubers, and because the plants are shallow-rooted, too little rain will be difficult to recover from.

Potatoes need a period of dry weather after the plants have died down to harden off the tubers and enable harvesting.

If you're thinking about growing potatoes on your whenua, check your region's rainfall and rain intensity. This is important while your potatoes are growing and when you are harvesting.

See NIWA for more information.

Potatoes are an annual crop, meaning you will get one crop over a 12 month period.

When planning to plant potatoes, you will need to consider your geographic location and the types of potatoes suited to this location. Different varieties of potatoes will grow better in the North and South Islands due to temperature and rainfall.

For advice on what varieties of potatoes suit your whenua, talk to Potatoes New Zealand.

Potatoes New Zealand

There are five phases of potato growth:

1. sprouting phase, when the potato sprouts and roots begin to grow,
2. leaf formation,
3. stolen formation and flowering,
4. bulking of tubers, and
5. maturation, when the canopy vegetation dies back.

Seed potatoes are planted into well-cultivated, furrowed rows of soil using machinery.

Potatoes are very sensitive to frost, so planting should be held off until the temperature and moisture conditions on your whenua are favourable. In Aotearoa, this is usually from September to December.

Potatoes will grow for 90 - 160 days before they are ready to harvest.

Potatoes are classified into two main crop types - early and main. Early crops are ready to harvest when the flowers are fully open. Main crop types need to wait until the foliage has completely died off before they can be harvested.

Harvesting potatoes is done using machinery. Timing is dependent on what type of crop type you have planted (early or main) and how much opportunity the tubers need to harden off.

After harvesting your potatoes, the crop is transported to the packhouse.

Packhouses will wash, inspect, grade and pack your potato crop before they are distributed to the domestic or export market in the best possible quality.

Potatoes can be affected by fungal diseases and pests like blight and potato pysllid. You will need to consider using pest management methods, such as:

• counting the number and species of pests weekly
• monitoring crops to assess plant health
• making the environment attractive to insects that can eat pests
• targeted use of fungicides and pesticides.

Potatoes New Zealand Inc.

Potatoes New Zealand Inc. (PNZ) is the industry association representing the interests of the New Zealand potato industry. Grower Members are actively engaged in the production of potatoes in New Zealand for commercial processing, domestic fresh market, export, and pay a levy. There are 170 Grower Members.

Learn more about Potatoes New Zealand.

Potatoes New Zealand

PNZ is fully integrated across seed manufacturing, potato production, and processing entities. PNZ works closely with MPI and Ministry of Foreign Affairs & Trade (MFAT), to promote new market access arrangements and compliance standards.

You might choose to sell your potatoes on the open market or to secure a contract to supply a processor. If you want to supply potatoes to a processor you will need to secure a supply agreement before you plant your crop. Prices paid for your crop are set down in your contract. Processors include McCains, Talleys, Mr Chips, Bluebird, etc. For example, McCain Foods in Timaru is supplied by 12 potato growers in Canterbury and processes 30% of New Zealand's potato crop. All growers are contracted for certainty of supply and quality.

If you choose to sell your potatoes on the open market you will typically sell your crop to a wholesaler like Turners and Growers or MG Marketing. The wholesaler sells your crop to supermarkets and other retailers. Wholesalers do not usually undertake supply agreements and the price you receive will be determined by market conditions at the time.

Turners and Growers

Export market

New Zealand's potato export market was worth about $102 million in 2021, with Fiji making up 75% of this market for fresh potatoes. Due to the rigorous plant health requirements of most countries, exports of fresh potatoes are limited (for example, New Zealand potatoes can't be imported into Japan and Australia). However, frozen processed potatoes are exported to Australia and Japan along with French Polynesia and Papua New Guinea.

The domestic market for potatoes generates about 7 times more value than export sales.

New Zealand Potatoes - Exporting statistics

Scale

Potatoes can return a profit from a small (5-hectare) or large-scale enterprise. Potatoes are grown across Aotearoa, from Northland to Southland, with the majority of production in Canterbury and Pukekohe. Turning a profit from growing potatoes depends on several factors, like:

• your location - access to the market, or infrastructure, or to a packhouse
• your production practices - modern machinery and equipment or smaller scale efficiencies
• the market demand and access to the market
• your sales strategy (whether you choose to sell your potatoes on the open market or contract supply to a processor)
• your operational efficiencies - larger farms may benefit from economies of scale.

Equipment and infrastructure

There are various tools and equipment needed for growing and harvesting potatoes. These include:

• tractors and other field machinery, for example, harvesters, potato planters
• ploughs
• harrows
• seeders
• cultivators, and
• irrigation systems.

It's estimated that you'll need to grow at least 5 hectares of potatoes to offset the costs of investing in machinery and equipment. Contractors could be used to provide some of these services if you are farming on a smaller scale.

After harvesting your crop, you'll need well-ventilated storage sheds to maintain the quality of your potatoes. You'll need to sort, grade, clean, and pack your potatoes into bags or crates, ready for the market. If you're located near a packhouse and can partner with them, they'll help you with this.

Jobs and people

Your people and labour requirements are seasonal, based on key milestones, like planting. You'll need a mixture of unskilled labour, as well as specialists. The specialists will help you with:

• managing the crop cycle,
• pest management techniques,
• harvesting and,
• post-harvest management.

The peak demand for labour and specialists by potato farmers is during planting and harvesting times.

Here is an example of a potato farm in Pukekohe, let's imagine it had 10 hectares of potatoes grown last year.

It yielded 580 tonnes of potatoes, bringing in a revenue of $250,000.

It had $150,000 in expenses, and the farm made a profit of $100,000.

Post-planting, it took 5 months for the potatoes to be ready for harvest and then sold (time to commercial yield).

Operational costs

The estimated operational costs to grow potatoes are around $15,000 per hectare per year. This depends on factors, like:

• the scale of the operation
• level of mechanisation
• specific farming practices
• regional and locational factors
• market conditions.

Labour costs can be significant, especially when you're first setting up your farm. Some other examples of costs that you'll need to consider are:

• seeds or sets
• fertilisers
• pesticides and herbicides
• agrochemicals for potato cultivation
• skilled and unskilled labour
• permits, licenses, or certifications
• compliance with regulations and food safety standards.

Costs to consider

There are some costs you will need to consider, and these will change with the amount produced. Here are some examples:

Yield (and time to profit)

It typically takes several years to establish a sustainable and profitable operation.

Maximising the number of good quality potatoes grown will increase the profits you earn. Factors that can contribute to higher potato yields include:

• crop management (specifically crop rotation, soil structure management, pests and diseases, and irrigation)
• variety selection (you need to choose the best varieties for your region)
• planting density
• nutrient management
• weed control
• harvesting at the right time.

Revenue

Returns from potato farming are influenced by a variety of factors, including:

• market conditions
• yield
• quality
• production costs
• pricing strategies
• events beyond your control, for example weather conditions or market fluctuations.

Things we can do to create better returns include:

• efficient practices to maximise yield and production.
• market demand and pricing
• quality and grading
• Cost management
• Storage and post-harvest handling
• Value-added opportunities

To help you make informed decisions and maximise returns, it's important for you to:

• stay informed about market trends through research.
• maintain good relationships with buyers.
• regularly assess your farm's production and financial performance through tracking costs.

Operating profit

To estimate your operating profit, you'll need to look at the amount of money generated from selling your potatoes, minus your production costs. Some factors may affect your revenue and influence your farm's operating profit. These include:

• farm size or the size of your potato crop area
• yield - the quantity of potatoes sold
• market conditions and fluctuations
• production costs and efficient farming practices
• pricing strategies
• weather conditions.

You will need to consider your production costs, which can include:

• labour
• seed costs
• fertilisers
• irrigation
• pest and disease management
• machinery maintenance
• storage
• packaging
• marketing costs.

These costs can be affected by having efficient farming practices and effective cost management.

Each farm will have factors specific to them and different market dynamics. Keeping accurate records of your production and financial records can help you see where improvements could be made and increase your operating profit.

The total export value of potatoes from New Zealand was $102 million in 2021 (including fresh potatoes and frozen processed potatoes). The authorities can provide information on what's needed to export potatoes, including:

• procedures
• documentation
• fees or licences
• packaging standards
• biosecurity requirements.

Read more about regulations and compliance

To export potatoes, you need to follow legislative requirements, including:

• paying levies to Potatoes New Zealand and Horticulture New Zealand on the sale of your potatoes
• meeting export requirements, like documentation and packaging standards
• ensuring food is grown so it can be sold under the Food Act 2014
• meeting regulations around risks to freshwater.

Potatoes NZ - Industry overview

Growers are supported by Horticulture New Zealand and Potatoes New Zealand. These organisations collect compulsory levies under the Commodity Levies Act 1990. Potatoes New Zealand collects $0.85 per $100 of sales, and Horticulture New Zealand collects $0.14 per $100 of sales.

Learn more about levies.

You must comply with National Programme 1 requirements under the Food Act 2014. This includes:

• following safe food practices, like checking for pests and using clean water
• registering your business with either your local council or MPI
• getting your business verified.

Learn more about National Programme 1.

You will need a freshwater farm plan, either now or by 2025 if your whenua will have:

• 20 hectares or more of arable and/or pastoral use, or
• 5 hectares or more of horticultural use, or
• 20 hectares or more of combined uses.

These plans identify actions to manage and mitigate risks of on-farm activity to freshwater. They must be certified and audited, then recertified every 5 years.

Learn more about freshwater farm plans.

Some additional certifications and registrations may make your potatoes more appealing to buyers.

You can choose to get certified with New Zealand Good Agricultural Practice (NZGAP) for a yearly fee. Some retailers and wholesalers only take crops from an NZGAP-certified supply channel.

Learn more about NZGAP.

NZGAP - Environmental management system

Getting organic certification by BioGro New Zealand is another way to lift the value of your crops.