Potatoes require well-drained, slightly sandy soil in order to thrive. This type of soil is often low in nitrogen, a nutrient the potatoes also require for healthy growth. Fertilizing the potatoes in your home garden both before planting and once they are established helps ensure your plant produces healthy, well-formed tubers for use in the kitchen. While a soil test tells you the exact fertilization your garden needs, using general fertilizer requirements will still give your potatoes a good chance at healthy growth.
Loosen the soil to 12-inch depth using a power tiller. Remove any stones or large roots from the bed and dispose of them.
Spread 10 pounds of 10-10-10 analysis fertilizer over every 100 square feet of garden bed in the spring about one week before planting the potatoes. Work the fertilizer into the top 10 inches of loosened soil.
Fertilize potatoes a second time six weeks after planting. Work 1 tablespoon of 10-10-10 analysis fertilizer into the soil by each plant. Work the fertilizer in 6 inches away from the stem of each plant so you don't get fertilizer directly on the roots, which may cause damage.