A light spot while the potatoes are chitting allows sprouts to grow short and sturdy. If they are in a dark position, sprouts are usually drawn, weak and can break off during planting.
In temperate areas, chitted potatoes can be planted out in early August. Once they have been mounded a few times, many areas will be past the time for late frosts.
It is important to select a good spot for them to grow as potatoes need a sunny (at least five hours a day) position where they will not be competing for moisture.
They also benefit from being in a sheltered area that does not receive strong winds.
Next, the soil needs to be well-worked – this means that it has been dug over to a depth of 25-30cm. This will allow the potatoes to grow and multiply.
As with many plants, there are a number of different potato varieties available.
Three favourite varieties are agria, heather and jersey benne.
Agria is an early main cropper and has a long oval shape with yellow flesh that is perfect for roasting, chips and wedges.
Heather is a main crop potato that is oval and has a distinctive purple skin with white flesh – it’s great for boiling, roasting and casseroles.
Jersey Benne is an early variety with a kidney or oval shape, with white skin and flesh which is excellent for mashing or boiling.
If you do not have enough space in your garden for a row or two of potatoes, you can grow them quite successfully in containers, large plastic bags or a bucket (say 35 litres), using a good quality mix such as Ican Premium Potting Mix or Tui Vegetable Mix.
Make sure there are plenty of drainage holes.
Place tubers in the potting mix near the bottom of the container, covering them by about 50mm.
As the sprouts grow, keep adding the potting or vegetable mix until it is up to the brim of the container, add a dressing of Ican Potato Food each time the potting/vegetable mix is added or some Tui Novatec every two months.
Harvest when the tubers are ready.
Here is a seven easy-step process for delicious home-grown spuds.
Step 1
Site selection; taking into account the factors previously discussed (sun, moisture and wind).
Step 2
Purchase certified seed potatoes, spread out in a warm light location and leave to grow sprouts (about three weeks).
Step 3
Prepare the soil for planting. Remove any weeds from the area and dig over the soil to 25-30cm deep, working the soil to a fine texture. Spread both Potato Food and Garden Lime over the soil and mix well so that none will come into direct contact with the potato tubers when they are planted. Add gypsum to the garden if the soil is clay and raise the bed to improve drainage if required. If the soil is very light then the addition of compost or sheep pellets will improve moisture retention.
Step 4
Plant seed potatoes approximately 10cm deep, 35-45cm apart and in rows approximately 75cm apart. This gives a good amount of space to later “mound up” soil around each plant.
Step 5
Check weekly. When shoots have emerged and are reaching 20cm high, it is time to start mounding. Mound up the soil, almost completely covering the plants. Continue to check regularly. Once they have grown another 20cm, mound them up again. Having so much of the stem covered will ensure a decent crop, as tubers form up the buried stems. Sprinkle the soil around the plants with Potato Food each time before you mound the soil up. By covering the stems of the plants with soil, you are also providing protection from any late frosts. Any tops remaining should be covered with frost cloth if a frost looks likely.
Step 6
Pest control and care. The potato/tomato psyllid has become a problem throughout New Zealand. The symptoms often don’t show up until it is too late as the insects can only be seen under the microscope. However, it is easily controlled using Yates Mavrik or Yates Success on crops growing from November to April. If you like to avoid using sprays then I suggest planting sooner rather than later, as the insect problem becomes more prevalent as summer progresses (December onwards). By starting your potato crop now, they will likely be ready for harvest before needing treatment for psyllid.
Step 7
You know your potatoes are ready for harvest when the plants flower. There are a few varieties (such as rocket) which do not flower, so in this situation it can be useful to mark on the calendar when they would be due. Generally, early varieties will be ready to harvest around three months from planting while four months for late and main crop varieties is more suitable. The later and main crop varieties are usually better for storing.
Gareth Carter is the general manager of the Springvale Garden Centre in Whanganui.
