Maximising Your Potato Yields

Potatoes are an extremely popular crop in New Zealand. In fact, more space is dedicated to growing potatoes than any other crop! With the right cultivation techniques, growers will be rewarded with generous yields and even improved soil structure. To get the most out of your potato crop and, even more importantly, your soil, there are a few factors you might consider.

Planting season

The ideal time to plant potatoes in New Zealand is between September and December. Potatoes are susceptible to damage from frost and shouldn’t be planted in temperatures below 10°C. Temperatures above 30°C can also reduce the quality of potatoes, so a happy medium provides the best conditions. 

Like any crop, potatoes thrive in soil that is well conditioned with good structure and drainage. Waterlogged soil can lead to crops rotting in the ground. Humic acid provides benefits to the soil that are almost too good to be true. But, its benefits really can’t be overstated. Humic acid is concentrated organic matter, with quality products derived from leonardite shale. Adding Humic acid to the land gives the soil a more stable structure and better drainage properties. It also promotes water retention which is the most limiting factor for plant growth and productivity, enabling crops to cope under harsher conditions. And increased Cation Exchange Capacity to ensure crops acquire rich nutrient levels for plant health and quality production.

While good quality soil is always important, it is especially necessary for root crops like potatoes. As they grow underground, potatoes are more exposed to the contents of soil, whether they are nutrients or toxic chemicals. For this reason, opting for organic soil amendments and fertilisers such as our BioGro certified products will improve the quality and health of your produce.


The power of humic and fulvic acids

A trial undertaken by a New Zealand potato grower showed that using Roots, Shoots and Fruits’ humic acid product, Humax, provided clear improvements to his yield, even in the poor conditions of waterlogged soil. The average weight and size of Humax treated crop was greater than the control and the yield was 12 per cent higher. If these results seem impressive, using Humax on well-maintained soil would provide even greater benefits and adding it in subsequent seasons would only compound those benefits over time. You can read about the trial here.

The trial also noted that with the inclusion of our fulvic acid product, Mobilizer, the results of the trial would have been even better. Fulvic acids are similar to humic acids but also have some crucial differences. For one, fulvic acid molecules are much smaller than those of humic acids which enable them to attach to nutrients and deliver them directly into a plant’s root system, increasing yield. This partners well with humic acid’s water retention capabilities, making soils more biologically active due to a higher oxygen content. Check out our trials on potatoes using Mobilizer here. 

Potatoes are a great crop to grow in New Zealand and, with the right techniques and reliable products, you’ll be blessed with high yielding harvests in no time. 

If you have any questions or issues with your crop this season, we’d love to hear from you and to help you out where we can. Get in touch today – email Molly at