About the different potato types

Potatoes vary in their make up. Some are called ‘waxy’ potatoes and these are lower in starch and hold together much better when cooking - they are more suitable for salads and boiling, the classic ‘new potatoes’.

Other varieties are called ‘floury’ potatoes and these are higher in starch and ideal for wedges, chips, roasting and mashing.

Early and early-mid season potatoes tend to be more waxy, and the later varieties more floury.

Well-known early potatoes include Jersey Bennes and Rocket, and this year we also have Charlotte and Marilyn, two new cultivars that are heavy croppers and able to be harvested after only 70-80 days. All these are 'waxy' potatoes.

Mid season potatoes can be waxy or floury and are flexible with harvest time. They can be harvested almost as early as new potatoes but can also be left in the ground to produce more, larger potatoes and be harvested when the tops begin to yellow off, after around 120 days. As well as Ilan Hardy and Heather, we have two new cultivars - Bute and Vivaldi. Vivaldi is an outstanding potato, a very heavy cropper with a great taste.

Main crop potatoes include the popular Agria and Desiree cultivars and this season we also have Van Rosa, a New Zealand bred cultivar which has Desiree as a parent. All these are 'floury' potatoes.

When to Plant Potatoes in NZ

Potato planting time varies depending on where you are in NZ. They can be planted as early as late winter as long as the soil is well drained and you protect the new growth from frost damage.

For the earliest crops, we suggest planting a month or so before the last frost in your area and making sure you protect any new growth if a frost looks likely. With early varieties taking 70-80 days from planting to harvest, you should plant mid to late September to be sure of having new potatoes for Christmas.

Mid season and main crop potatoes can be planted any time up to the end of January, or even later, as long as there is enough time from planting until harvest. Early autumn frosts will knock the foliage down and growth will end, so it's best to make your last planting 120 days (four months) before the first autumn frosts in your area. Early unexpected frosts can be dealt with by covering the plants.

How to plant Seed Potatoes

Step 1 – Prepare them for planting

'Chit' your seed potatoes. Chit is one of those ancient and peculiar gardening terms which seem designed to confuse new gardeners. What it means is to get your potatoes sprouting. We greatly dislike these weird expressions and we're going to say 'shoot' or 'sprout' instead.

• Place your seed potatoes inside in the warmth, rather than in the cold garage
• Make sure there's some air movement and that they are kept dry
• A lot of people place them in an egg tray to separate them and allow good air movement
• After a few weeks, shoots will start to appear
• They're ready for planting once the shoots are about 2cm long

Step 2 – Prepare the Soil

Loosen the soil well before planting and improve heavy ground by working in plenty of quality compost to improve the soil structure and drainage.

Potatoes benefit from fertilising, so work some fertiliser into the soil as you prepare it. Use a balanced fertiliser with N:P:K around the same levels. Potatoes prefer a slightly acid soil, so don't use any lime. Most soils are slightly acid and will be just right.

Step 3 – Prepare your trench and plant

Prepare for planting by digging a v-shaped trench, 15-20cm deep in the centre.

Place your seed potatoes in the trench, spaced out with about 40cm between each one. If you're planting a lot of potatoes and need more than one row, space the rows 40cm apart so they all get plenty of light.

Don’t fill the trench completely with soil after planting, just cover the planted potatoes with at least 5cm of soil. Cover with more soil each week to keep the shoots covered, until eventually the trench has been turned into a mound of 15-20cm in height. The more growing stem beneath the soil, the more opportunity for the plant to produce potatoes and the bigger your crop will be.

Add a little fertiliser each time you cover the shoots, but don't overdo it, half a teaspoon per potato is enough.

Step 4 – Protect from insects

Once planted, consider covering the crop with some insect-proof netting to keep out the potato-tomato psyllid, a small insect that can carry a damaging bacteria. Potatoes infected with the bacteria show stunted growth, yellowing foliage, reduced potato yield and 'zebra striping' of dark stripes inside the tubers. Using netting is a great non-spray method to keep insects off the crop.

Because the plants can be attacked by the psyllid at any growth stage, put the netting on the potatoes once planted and keep it on until harvest. Put the netting on loosely at the start or loosen it as they get bigger. Make sure the plants aren’t pushing hard against it or being damaged and that it is tucked into the dirt securely to stop insects getting in under the edges.

Growing Potatoes in Bags

In small gardens, or even on apartment patios, potatoes can be successfully grown in pots or special potato planting bags.

Potato care while growing

Once you've finished mounding the potatoes and the tops are growing freely, it's time to change over to ongoing plant maintenance.

Fun Fact Time

This Potato Growing Guide has let me satisfy a long-standing urge to include a 'Fun Fact'.

While a majority of our online customers for bulbs are female, and social media followers almost 95% female, potato growing is very male.

We're not quite sure why, but we think it harks back to the days when we had quarter acre sections for a reason - a huge vege garden was standard and providing fresh produce through the year and especially for Christmas was a matter not just of economics, but of pride, and that garden was very much a male domain.

Whatever the reason, we know that potato growers are very particular about their varieties and timing.

We've taken it as our mission to break a few moulds and get gardeners trying some new ones - you might just find a new favourite potato to grow! Check out our new cultivars this season - Charlotte, Marilyn, Bute, Vivaldi and Van Rosa. These are all heavy croppers and well worth a try.

Common Potato Problems

Common Questions

Final Advice

Success with Potatoes comes down to a few essentials:

1. Free-draining, fertile soil with some compost added
2. Full sun will give the bext crop
3. Fertilise well with lower-nitrogen fertiliser
4. Water well once a week, but don't drown them
5. Protect from insect and fungal damage

With those basics right, you'll have a top potato crop and be the Christmas dinner hero.