Our seed potatoes are from lines that have been saved and selected by our New Zealand ancestors over many generations. These seed potatoes have been saved in real gardens, in living soil, and selected for health, disease and pest resistance as well as production by Kōanga ever since they arrived in our collection.. for many of them that is 30 + years ago. We trust you too will build a relationship with them, get to know them as we have, and get much pleasure and nutrition from them for your family. You also could save the best for your own seed potatoes next year (see details further below)
Upon receipt please open your package and open the bags of potatoes and remove them from the bag.
Chitting your potatoes
Traditionally potatoes are frost tender so plant after the last frost in early spring. Before planting ‘chit’ or sprout the potatoes. Chitting is the process of placing seed potatoes in a cool, but frost free, light but shady place to encourage strong sturdy shoots to grow before they are planted in the ground. They can be hung up in onion sacks in a dry but light, shady place under eaves or in a garage or shed to store them and then they can be laid out in a tray (egg cartons are useful) to sprout, again in a light but shady place. The aim is to have a small number of shoots, not masses of sprouts. If the shoots are very long they can still be successful but are harder to plant without damage so short, sturdy shoots are best. If you have too many shoots you can rub some off.
After sprouting large potatoes can be cut into sections about 2″ wide. Each piece should have at least two buds. After cutting the potatoes, let them sit at room temperature for two or three days for the cuts to seal.
Potatoes are best planted into a trench. We dig two trenches along a garden bed and put a layer of soil amendments at the bottom of each trench. Good compost or well rotted manure along with seaweed, wilted comfrey leaves, Natures Garden and Active Calcium are good additions to the trench. Position the seed potatoes at approximately 25 cm spacings along the trench before filling it in. Once the tops of the plants have emerged mound up the soil around each plant so that there are now two ridges running along the bed. As they grow bigger mound up again. An alternative method is to mulch the bed and then mulch again once the plants have grown up through the first layer of mulch. Or the plants could be earthed up once and then mulched as they grow bigger.
Keep an eye on the plants as they grow. Occasionally plants will have all crinkly leaves which is a sign of virus. These plants are best removed and certainly should not be used for seed potatoes. A fairly recent problem for potato growing in New Zealand is the Tomato, Potato Psyllid. These small insects are sucking feeders that reduce crop size. Plant growth is stunted with curling leaves often with purple tips and aerial tubers forming. If you experience reduced crop size due to psyllids then best plant as early as possible to avoid the psyllid which only becomes active in warmer weather. Those with short seasons may need to resort to planting before the last frost (we plant in mid September and frequently have frosts until late November), and plan on having frost cloth and hoops over the potatoes until you are sure there will be no more frosts. It is often easy enough to keep hilling them top until November some time but after that they will need covering. A hard frost will get the tops through frost cloth if it is sitting on the leaves. It is best to place the frost cloth on hoops over the potatoes. If you can the potatoes will do better if planted in August.
Kōanga sells Psyllid Solution, a very finely ground form of diatomaceous earth which if applied regularly using a back pack sprayer (weekly) is very effective at keeping the psyllid off the tomatoes and potatoes and peppers.
Early varieties are ready to harvest when the flowers are fully open, and later varieties once the foliage has died down.
Saving your own seed potatoes
Potatoes need annual careful rogueing to maintain strong true to type seed lines. All plants that appear for any reason at all to be not quite normal must be removed as early in the season as possible. Disease is spread in potatoes by insects such as aphids that are sap feeders, so ensuring rogueing is done early in the season makes a huge difference to the potential spread of disease.
The first rogue is done during or before the seed is planted. When you take your seed from the onion sacks where it was kept hanging all Winter under the eaves your shed etc., discard any seed that is rotten or feels very soft, or has potato tuber moth faeces hanging from the eyes. Place seed in trays to grow shoots 4 weeks before planting, which now that we have the psyllid in New Zealand must be before mid September.
The second rogue can be done at planting time. Any seed potato that has weak shoots, or shoots of a different colour, can be discarded. Once the potato tops emerge, any leaves that show crinkling, yellow streaks, stunted growth etc. must be removed. Once flowering begins you can rogue out any that have different coloured flowers or are weak plants.
Harvest time is your next opportunity to maintain strong true and productive seed. Harvest your plants individually and keep the crop that grew under each plant in its own pile. Once you have finished digging you can go along your lines and select the plants that have the heaviest best looking tubers; these are your seed tubers. The largest tubers will grow your best potatoes next year but you may choose to keep the egg sized potatoes as your seed because of the suitability of that size for planting.
Potato seed is easy to save, as most of the work will already be done by the harvest stage. Simply choose your best large or egg size potatoes and hang up in an onion bag in the light to stop them sprouting, or in a sack in the dark and cool to stop them sprouting. Those that begin actively sprouting first in Spring are the early potatoes, the ones that want to be planted first and that grow better in the cooler season.