How to Grow Potatoes

These versatile root vegetables are easy to grow, making them a great choice for novice gardeners or when introducing children to gardening. 

Planting Potatoes

Potatoes grow best in a sunny site with rich, fertile, free-draining soil. To grow potato crops you first you need to purchase seed potatoes of the particular variety you want to grow. You can purchase them from garden centres or you can grow them yourself. Once you have your seed potatoes put them somewhere dark for a period 1-2 weeks, during which they should begin to sprout.

Tips on planting

  • Prepare soil by mixing Compost and Potato Fertiliser into the soil and working in well.
  • Root vegetables need room to grow so plant seed potatoes 5cm deep and 25-30cm apart with approximately 70cm between rows. 
  • As they commence growing, and when plants are about 20cm high, regularly ‘mound up’ the soil up to around 10cm above existing ground level – on both sides of the plant, weekly or fortnightly. You can even cover some of the new shoots and lower leaves as this will help towards a better crop. This ‘mounding up process’ helps warm the soil so the plants grow more quickly, while also protecting against late frost, and most importantly preventing greening of your young potatoes as they form.  
  • Potato crops will mature in approximately 3-4 months after planting depending on the variety and the weather of that particular season.  
  • Potatoes can be harvested once the flowering has finished and the green tops of the potatoes begin to turn yellow. Don’t be tempted to pull them out early! To ensure potatoes have reached maturity start at one end of the row with a fork and dig lightly to check the potatoes are ready for harvest. If they are too small, leave them a bit longer.  
  • Once harvested potatoes should be stored in a cool dark place.
  • If you are short on space, you can successfully grow potatoes in containers such as buckets, tyres, pots and even bags.

Choosing the Right Variety

Potatoes come in a wide selection of varieties, each varying in size, shape, flavour and timing when they crop. Planting the right variety of potato at the right time is very important. Varieties typically fall into two groups depending on when you are planting: Early Varieties and Main Crops. Early cropping varieties should be planted in early spring, while a maincrop potato is best planted in late spring or early summer.

Early potatoes These varieties usually mature more quickly – within 3-4 months. Many people start planting them from June (in warmer regions – later in cooler regions). Ensure crops are planted in spring to be ready in time for Christmas. Early varieties to try: Illam Hardy, Cliffs Kidney, Jersey Bennes, and Marist Anchor.
Maincrop potatoes Maincrop varieties are normally planted from October through to March. Maincrop varieties to try: Aaron Banner, Rua, Urenika and Agria.
Red potatoes Try Red King and Red Rascal these are traditional south island varieties and prefer a colder climate.

Feeding and Watering Potato Crops

Give your potato crops a side dressing of Daltons Garden TimeTM Potato Fertiliser 2-3 times during the growing period but don’t over fertilise as it will lead to green leafy tops and fewer potatoes in the ground.

Potatoes are hardy and easy to grow and only need watering around once a week. Be sure you don’t over water them. The only time you may need to water more regularly is during an exceptionally dry period. 

Pests and Diseases 

If grown in the right position in the garden, potatoes don’t usually have any real problems and are mainly free of disease and pests.

Crop rotation plays an important role in ensuring potatoes remain disease and pest free. Avoid growing plants in the same location year after year as it can increase the risk of crops being affected by potato nematode.  


Gardening Terms Explained

Greening Potatoes that have turned green because they have been exposed to light.
Crop rotation Growing crops of vegetables in different spots each year in the garden.
Mounding up To mound or pile up soil around the base of a plant.
Potato Nematode A parasitic worm that attacks root and tuber vegetables.