If many spindly sprouts form, remove the weakest. Seed should be no smaller than a golf ball. Cut large seed up, leaving two or three eyes a piece. Apply sulfur or copper to cut section to prevent disease. Avoid planting seed during the wettest time of the year.
Potatoes prefer a loose well-drained soil high in organic matter, nitrogen and potassium.
An acid soil with a pH of 6.0 to 6.8 is ideal. Cultivate soil deeply and break up clay particles. Apply 25mm or so of old horse manure or ready compost. Incorporate well into the soil. Form trenches by digging about 250mm wide by 150-250mm deep and 60cm apart.