Nitrogen applied early in the growing season will aid in the growth of the overall size of the leaf canopy. Nitrogen being used at later periods of development helps to keep the leaves green and maximizes production.

Assuming your soil is in good heart and has had an application of manure, additional general fertiliser is probably unnecessary but additional potash will be beneficial. This can be gained by applying 250 grams of wood ash per square metre or laying comfrey leaves in the trench before planting and between rows. I have an article that shows you how you can make your own fertiliser for potatoes. More specific knowledgeChoosing the type of fertiliser for growing your potatoes is a matter of personal preference. There are many different ways you can help your potatoes grow, you can choose the organic route or standard chemical fertiliser.

Slow-Release fertilizer releases nutrients steadily over an extended period of time. This means you only have to fertilize once or twice a year. Granular fertilizers are lower in price in large quantities and convenient to store because there is no additional interference in the blending product.You should carry out a soil analysis by either buying a soil test kit online or by sending a sample of your soil to an agricultural testing lab. I have found many of the kits online in which you do the analysis are hard to interpret and are a little vague. A more specific way to do soil analysis would be to get your local agri supplies stores to arrange it.