(1) Obtain your seed potatoes in late winter and place them rose end (that is the end with most of the shoots or ‘eyes’) uppermost in seed trays, or empty egg cartons, which should then be placed in a cool, airy, light (but not sunny) spot such as a shed or garage so that the potatoes can start to sprout. If your seed potatoes are rather large, they can be cut in pieces with several sprouts just before planting.
(2) To plant potatoes, make V-shaped drills with your spade about 13 cm (5 in) deep and 60cm (2 ft) apart for early varieties, 75 cm (30 in) apart for main crop varieties. The early varieties need be no more than 30 cm (12in) apart in the drills; maincrop varieties should be 38 cm (15 in) apart. The seed potatoes should be set in the drills, rose end uppermost, and first covered with a handful of peat, potting mixture or fine soil to prevent damage to the new shoots.
(3) The drills should then be filled in with soil so that a slight ridge is left along the drills. Next, scatter vegetable fertilizer over the drills at the rate of 135 gm per sq m (4oz per sq yd). If there is still a risk of frost when the first shoots appear above the soil, draw a little earth over them for protection, using a hoe or spade.
(4) When the potato shoots reach 23 cm (9 in) high, it is time to begin the process called ‘earthing up’. Fork the soil lightly between the rows, and using a spade, pile the loose soil against the stems to produce a ridge 15 cm (6 in) high. Further earthing up can be carried out as the foliage develops so that the potatoes are eventually growing in ridges.
(5) When lifting potatoes, insert your fork into the soil well away from the haulm and then lift the haulm and its roots away from the row. Give the haulm a good shake and most of the potatoes will fall away cleanly. When the haulms of maincrop potatoes have withered, cut off the stems and remove them. Then wait 10 days and lift the entire crop.
Potatoes are first rate for cleaning newly broken grassland, as their heavy growth smothers weeds and their big root systems break up the clods of soil, leaving the land in good condition for succeeding crops. Soil should be dug at least 10 in. deep as early in the autumn as possible and left rough for the winter. Manure or compost may be applied at 1 cwt. to 15 sq. yd. Lime should not be used unless the ground is known to be sour, when application should be restricted to about 6 oz. per square yard of hydrated lime. This may be given as a top dressing six or eight weeks after digging in the manure. Chemical fertilizers should be employed, whether or not dung is available.
The best planting sets come from districts in Scotland and Ireland in which virus diseases are almost unknown. Home-saved planting sets may be used for one year, provided there has been no virus disease, but new stock should be imported from virustfree districts at least every second year. Sets should be obtained as early as possible. Immediately on arrival, stand them with their eyed ends uppermost in shallow boxes and place these in a light but frost-proof place.
Early potatoes may be planted outdoors in a sheltered position in early March. Maincrop varieties are planted during April. Spacing for earlies should be 1 ft. apart in rows 21 ft. apart; for maincrop kinds 15 in. apart in rows 3 ft. apart Methods of planting vary greatly. One of the simplest is to take out with a spade a Vtshaped trench. about 5 in. in depth. The tubers are spaced in this, care being taken to keep the shoots uppermost and not to break any, and the soil removed is drawn back with a rake or draw hoe. Large tubers may be cut so that each section has at least two sprouts.
Earthing up must begin as soon as the shoots appear through the soil. This is particularly important in the case of the earliesttplanted potatoes, as the sprouts may be killed by May frosts. Pull soil over them with a draw hoe and continue to earth up week by week until the ground is all drawn up in flatttopped ridges about 9 in. in height. Digging of earlies can start as soon as the tubers are of usable size. For late varieties digging should be delayed until the skins of the tubers are mature and will not rub off readily. Exception to this rule may be necessary if disease is severe, when it may be desirable to lift the crop without delay to save what there is. If some tubers are to be saved for planting the following year, good plants should be marked for the purpose and dug before their tubers are quite ripe. The tubers should then be left on the surface for a few days to green. Potatoes for eating must not be allowed to green.
Store all in sacks in a dark, dry shed, outhouse, etc., temperature 40-45° F., or in clamps in the open. These are ridge-shaped mounds of tubers, 4-6 ft. through at the base, covered with 6 in. of clean straw and 9 in. of beaten soil, Clamps must be made in a well-drained place. It is an advantage to place straw beneath the potatoes. A handful of straw should be drawn through the soil every 3 ft. along the ridge for ventilation.
Varieties are numerous. A few of the best are as followsEarlies: Ulster Chieftain, *Home Guard, *Arran Pilot, Sharpe’s Express, Duke of York, *Ulster Chieftain, Ulster Premier, Ulster Prince and Epicure. Second Early and Maincrop: *Arran Banner, *Arran Peak, King Edward, *Catriona, *Dunbar Standard, *Great Scot, *Pentland Dell, *Majestic, *Dr McIntosh and *Craig’s Royal. Those varieties marked with an asterisk are immune to wart disease.
The principal diseases are potato blight, virus, scab, wart disease, and blackleg. Slugs, eelworms, and wireworms are pests which do much damage.