PlantFiles: Potato
Solanum tuberosum

Everyone should try growing potatoes. The flavor and texture of a freshly dug potato is like no other. If there is no room in the garden or the soil is not loose enough, a trick I have seen is to use some chicken wire to make a cage, and use fluffed straw to grow them in. I don't know personally how well this works, but I did see it on a gardening show.

The humble potato needs no description. Even so here it is: A tuberous crop of small to large usually brown tubers, commonly used in cookery in the Western world. The leafy parts commonly called the haulm has ovoid, pinnate, mid green, bristly leaves which branch out from the main stem. Bears small, often whitish - green flowers on terminal stems and small spherical fruits follow if allowed.

Flowers depend on the type of crop but look for them from May onwards.

Earlies

Early or New potatoes are summer cropping varieties. The yield is much lower than maincrop varieties but have the added advantage of using less space and avoid blight. Not good for storing.

Second Earlies

Crop is similar to earlies but lifted later, between June and August. Treat as earlies.

Maincrop

Maincrops are much higher yielding, need a large space and can be lifted as late as October. The tubers are good for storing throughout the winter.

Planting

Obtain seed potatoes (small, disease free tubers from reputable suppliers) in early Spring and set in egg boxes with a layer of dry peat to sprout, place in a sunny, frost free spot. This will take about 6 weeks Don't pull the sprouts off. This is vital for Earlies and useful for Maincrop. Plant out in prepared beds in mid March - early May but cover over if frost is predicted.

They aren't fussy about soil type but they are useful for reclaiming grassland. They like a sunny position and a deep soil. Dig trenches and place the tubers sprout side up 12 inches apart from Earlies and 15 inches apart for Maincrops. Each trench should be 2ft apart for earlies and 30 inches for maincrops. Cover over the tuber and form a small ridge of soil over them.

When the haulm is 9 inches high you will need to 'earth up' which means drawing the loose soil from between the trenches and piling it against the stems in a flat top ridge about 6 inches high. This is to prevent the tubers from going green.

They need constant watering while the tubers are forming and the whole area needs to be kept weed free. The haulm will eventually cover the area and so prevent weeds themselves but in the early stages they must be kept free from competition.

Harvest

Earlies

Harvest in June-July after the flowers open. Move some of the soil from the ridge to see how big the tubers are. When they are chicken egg size they can be lifted carefully with a fork well away from the haulm.

Maincrop

Harvest September - October although they can be lifted earlier if for immediate use. Wait until the haulms are brown and cut them off, wait a further week or two before lifting. Dry them off on the surface of the soil for a couple of hours and store them in a dry, dark place.

Try to lift all tubers because they will produce many volunteers the following season from even tiny tubers.

All green parts including green tubers must be avoided as they are poisonous.

Pests and Disease

There are seemingly endless pests and disease for potatoes. Blight is the most serious infection and all infected plants must be dug up and got rid of, do not compost them. Various sprays are available to slow the disease down but there is no cure. Correct watering is the best prevention.

Aphids, eelworms, wireworms, slugs and capsids are the main pests.