Every spring I look forward to planting potatoes. This rather humble crop is one of my favourites. For starters, it is hard to beat freshly dug new potatoes on Christmas day. This is possible if potatoes are planted by September at the latest in New Zealand. Another reason why I find growing potatoes so appealing is because they are rather easy to grow. I will outline my top tips for success later in this post.
This year, I am planting three varieties: Liseta, Jersey Benne and Agria. Liseta is an early crop variety which matures in just 70 days. It is supposed to be a very high yielder and was commended for this in a potato trial carried out by the New Zealand Gardener Magazine several years ago. Jersey Benne is also an early crop variety of potato which matures in around 90 days. It remains a firm favourite on the Christmas dinner table in New Zealand and I have always planted this variety ever since I started gardening about five years ago. Early varieties of potato such as Liseta and Jersey Benne have waxy skins and are ideal for boiling. Agria is a main crop of potato which matures in approximately 100-120 days. This variety is ideal for roasting as the flesh is more floury than early varieties such as Liseta and Jersey Benne. Perfect for hot chips!
A variety which I am very fond of but which I am unfortunately not growing this year in the interests of space is Heather. An early-main variety, Heather is a prolific cropper and the soft-skinned potatoes are perfect for boiling and for making potato salads. Another popular main crop variety is Rua. Like Agria, the floury flesh is perfect for baking or roasting.
I highly recommend using certified seed potatoes rather than relying on planting odd potatoes that have accidentally started sprouting at the bottom of an old bag at the bottom of the pantry. While the latter will probably produce potatoes, certified seed potatoes are preferable in the interests of avoiding diseases in the ground. If certified seed potatoes are used, then the resulting crop will come true to type.
Potatoes can be grown in a number of ways, including in trenches in the ground, in containers or in tyres. Having experimented over the years, I have found that the traditional method of digging trenches and burying potatoes in the ground is the most successful way of growing spuds. Container grown potatoes produced a pitiful yield. I have not tried growing them in tyres.
Start by mixing compost and sheep pellets generously into the area where you intend to grow potatoes. Dig a trench in the ground three times as deep as the seed potatoes you are planting. Work in some potato food fertiliser to give your spuds an instant growth boost. Line a row of potatoes in the trench, spacing each potato approximately 30 cm apart. Cover the trench with soil.
The key to growing potatoes successfully is to continue to mound the potatoes (i.e. cover around the tops of the potatoes with soil). This is essential to ensuring that the potatoes do not turn green and therefore toxic to consume. This occurs when potatoes come into contact with the sun. My advice is to mound potatoes as they grow. Be careful not to break the tops of the potatoes as you do so.
About a week or two from the time they are due to be harvested, you can ‘bandicoot’ some potatoes for a meal. This is also a good way to test whether the spuds are on target for their due date. You need only use your hands. Gently scrape soil away from the sides of a few potatoes. You should be able to feel potatoes as you do this. Very carefully separate them from the mother plant, if they are not already loose.
To harvest potatoes, I recommend using a fork rather than a spade. Work slowly and carefully. Start by digging about 30cm from the tops of potatoes, gently working your way inwards. Don’t worry if you spear a few along the way. Put these ones aside for cooking first, the others can be consumed later. I always use a willow basket with a handle when I harvest potatoes. If stored properly, potatoes can last much longer. We always store potatoes in a dark place in old hessian sacks, which prolongs their life.
Try to remember not to grow potatoes in the same place the following year in order to prevent diseases. It is also helpful to avoid growing tomatoes, eggplants, capsicums and chillis (which are in the same horticultural family is potatoes) in the same location the following year for the same reason.