Growing Potatoes: How to Plant, Grow & Harvest Potatoes

A comprehensive guide to planting, growing, caring for and harvesting potatoes.

— Written in collaboration with NZBulbs

(Above: Red potatoes and white potatoes are easy to grow in your home garden, for a bountiful harvest of pounds of potatoes.)

How to grow potatoes in your home garden — Tips for planting, growing and harvesting your own potatoes

Potatoes — the versatile and beloved root vegetables that make everything from golden French fries to fresh potato salads and creamy mashed potatoes. 

Potatoes have a rich history that spans continents. While they may be a staple in our supermarkets now, did you know that potatoes originated in the Andes of South America? Like so many of our most-eaten vegetables today, potatoes came to New Zealand from Britain and by 1880 they were a staple part of the early settlers’ diet. These humble swollen underground stems, known as tubers, have come a long way from their ancient roots, making their way into our home gardens and onto our dinner plates in a multitude of ways.

Together with NZBulbs, we’ve put together this guide with essential steps and know-how to successfully plant, grow and harvest your very own potatoes in your home garden. Let’s dig in! 

Harvesting potatoes

 

Where to Start —

WHAT ARE SEED POTATOES?

To grow your own potato plant, you need to start with seed potatoes.

Potato seeds are known as ‘seed potatoes’. Unlike regular seeds, seed potatoes look just like regular potatoes – just usually smaller. When growing potatoes, it’s important to plant quality seed potatoes – they should be certified disease-free seed potatoes. This way, you know you’re getting the best start for the best results. 

Seed potatoes usually come in packs of 5, 10 or 20. This will help you choose the best quantity for your household, depending on whether you want to try growing more than one variety or not.

Choosing which Type of Potato to Plant

There are many potato varieties available to grow. The type of potato you choose to plant will depend largely on what you want to do with it and when you want to harvest.

Seed potatoes fit into three categories – early, early-main and maincrop potatoes.

Early potatoes — are ready to harvest early (60-90 days after planting). This type in particular really need to be harvested early as they are not long-term growers. They also taste a lot better when harvested early – the classic early, sweet-tasting, new potato. Early varieties include Cliff Kidney, Jersey Benne, Rocket and Swift.

Early-main crop potatoescan be harvested early to get ‘new’ potatoes. Or they can happily be left in the ground until the top growth dies back and the skins thicken up. When harvested as mature potatoes, they are no longer ‘new’ potatoes, but larger and thicker skinned. Early-main varieties of potatoes are harvested around 70-80 days after planting and include Heather, Haylo, Ilam Hardy, Nadine and Purple Passion.

Main crop potatoes — need longer in the ground and should be left in the garden until the tops die back in autumn before harvest (around 90-100 days after planting). They will be larger, thick-skinned and also store well. Main crop varieties include Agria, Desiree, Red Rascal and Rua.

You can find many of these potatoes for sale at NZ Bulbs.

Waxy Potatoes vs Floury Potatoes

What’s the difference between waxy potatoes and floury potatoes?

When selecting what type of potato you want to plant, it’s also important to consider the make-up of the potato. You may have heard of the terms ‘waxy’ and ‘floury’ when it comes to types of potatoes. As a general rule, earlier potatoes tend to be more waxy types and the later varieties are more floury.

WAXY POTATOES

Potatoes known as ‘waxy potatoes’ are lower in starch and hold together much better when cooking. Waxy potatoes are more suitable for potato salads and boiling. Think the classic ‘new potatoes’.

FLOURY POTATOES

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

Tip: If you’re looking for a general-purpose potato, try Desiree or Rua — these are are good choice for most uses.

Tips for Planting Potatoes —

Potatoes like to be grown in a full sun spot, in well-drained soil. You can grow potatoes in the ground, in a raised bed, in pots or a grow bag.

WHEN TO PLANT POTATOES

Potatoes can be planted as early as two weeks before the last frost date in your area (usually mid-late spring). This means the frosts will be pretty well over before new frost-tender shoots emerge on your new plants. In saying that, the best time is to wait a little longer – as you really want the soil temperature to be starting to warm up a bit for the best planting conditions.

In frost-free areas you can plant potatoes late winter to early spring for early crops. Potatoes can be planted as late as December / January (early-late summer) for main crop types, with a harvest time in autumn for storage and winter use.

To work out exactly when to plant, take a look at the harvesting time for each variety. Work out when you want to harvest and calculate backwards for when to plant. Stagger your planting or plant different types (i.e. main crop and early) to ensure you have a constant supply of spuds.

HOW TO PLANT POTATOES

PREPARATION

Once you’ve bought them, remove your seed potatoes from the bag or container and leave them in a light, dry place for a few weeks so they can begin to grow shoots. (A garage bench or garden shed is an ideal place.) When the potato shoots are approximately 2cm long they’re ready to plant.

Before planting, work in some compost (and possibly some organic matter )into the soil to make it more friable (crumbly) and easier for the potatoes to grow. This will also make it easier for you to harvest them.

PLANTING

  • Next, dig a v-shaped trench about 15cm deep in your garden bed and place the seed potatoes in the bottom of it – approximately 40cm apart.

  • Don’t fill the trench back up at this stage, just cover the planted potatoes with at least 5cm of soil. New potatoes hate frost, so keep an eye on them and as the shoots start to push through. 

  • Cover them a little more each week until you have turned your trench into a mound of 15-20cm in height after 6-8 weeks. The more growing stem beneath the soil, the more opportunity for the plant to produce potatoes and the bigger your crop.

ROW COVERS —

Cover your potato crop with some insect-proof netting to keep out the potato-tomato psyllid (Bactericera cockerelli) – a small insect that can cause a lot of damage to tomato and potato crops. The netting is a perfect non-spray method to ensure your potatoes stay healthy and yield a great crop. 

Because the plants can be attacked by the psyllid at any growth stage, put the netting on the potatoes when you plant them and keep it on until you harvest. Put it on loosely at the start or loosen it as they get bigger. Make sure the plants aren’t pushing hard against it and that it is tucked into the dirt securely on all edges.

( Note: You can purchase this netting from NZ Bulbs. This type of mesh is strong and UV resistant, so it will last for many seasons.

Caring for Potato Plants During the Growing Season —

Potato care during the growing season:

Watering:

To keep diseases away, don’t overhead water your potatoes with much water (not excessively). Once planted, they should require little water – the rain should be enough to keep them going until they’re ready for harvesting.

Make your own crispy, golden French fries with homegrown potatoes.