Preparing Seed Potatoes
To grow potatoes, you must correctly prepare the seed potatoes. To prepare them, cut each tuber into chunks for planting. Ensure there are 2-3 eyes per chunk for the best results. Potatoes can be cut into multiple pieces as long as each piece has an eye. Small seed potatoes may be planted whole. Allow the cut side to dry and callous over several days before planting in the soil. You will know it is calloused when the cut side has dried and hardened over. This helps prevent disease after planting. The eyes of the potato are identified by dark, typically indented, spots on the tuber. This is where the plant will sprout from. Seed potatoes are much easier to grow because they have reached the appropriate age for sprouting and are less likely to carry disease.
After cutting your seed potatoes into chunks, begin chitting them if they have not already started to sprout from the eyes. This involves placing it in a sunny location that won’t get too cold. Allow the eyes to sprout and grow to be about 1-inch tall. The sprout should be either green or purple. A long, white sprout indicates insufficient light and may fail to grow in the garden. Planting seed potatoes that have started to sprout to this stage produce healthy plants more quickly than those grown from early eye formation.
Planting Potatoes
Plant your potatoes immediately after the last spring frost date for a late summer or fall harvest.Potatoes do not tolerate frost. Select a location in full sun (8 or more hours of direct sun per day). Dig a trench 4-6 inches deep. Plant your sprouted seed potato with the sprout side pointing up. Then cover it with about 3 inches of soil. Planting potatoes too shallowly may compromise any higher-set tubers. Space them 12-15 inches apart and space rows about 3 feet apart. Fertilize with a light nitrogen fertilizer at the time of planting.
Growing and Care Instructions
Mounding - As the potato plants grow, mound up the soil around the base of the plant to continuously cover the tubers. The mounds should be about 8-12 inches tall by the end of the season. It is okay to cover a few leaves during the earthing-up process. This will not damage the plant and may encourage more roots.While a few roots may form down from the planted seed potato, most of the roots and tubers will form above the planting level. Keeping the tubers covered is vital to achieving high yields and preventing toxicity. Tubers that are allowed access to sunlight can become green and not recommended for consumption.
Fertilizing - Fertilize the plants once again mid-season. Provide nitrogen, but only a little. Follow the manufacturer’s instructions if using a commercial fertilizer.
Water and Soil conditions - Ensure the plants receive regular water. Rainfall may be sufficient in some areas. The soil should stay evenly moist but not soggy. A sandy loam is best to promote plenty of airflow and room for tuber growth. Be extra attentive once the plant starts to flower, and do not let the soil dry out. Potato plants prefer temperatures around 65 F. The plant will fail to grow if temperatures are consistently above 80 F without adequate care.
Pest and Disease - Be aware of the health of your potato plants. Many varieties are naturally resistant to various viruses and diseases. However, pests can ravage a crop if left unchecked. Aphids and slugs are particularly drawn to potatoes. Implement a pest management protocol early in the season and be consistent. For healthy crops from year to year it is important that growers utilize crop rotation schedules.
Harvesting Potatoes
Young potatoes can be ready to harvest about a month before the full maturity. For full-maturity potatoes, the above-ground plant should die back and turn brown. Then, leave the tubers in the soil for 2-3 weeks to cure. This will increase their storage life. The plant will die at the first hard frost. If a hard frost is predicted in your area within the month, manually kill the plant beforehand to initiate curing.
When the potatoes are ready to harvest, use a shovel to loosen the soil about 12-18 inches around the base of the plant. Then, use your hands to dig up the tubers. Hand removal will reduce the chances of puncturing the tubers. A punctured tuber should not be stored but can be thoroughly cleaned and consumed.
Storing Potatoes
Potatoes can be stored for several months in optimal conditions. Store the tubers in a dark place after curing in the soil as described above. Avoid storing in plastic bags as potatoes require good ventilation over long periods of time. The humidity should be pretty high (around 90-95%) to avoid wrinkling. The optimal storage temperature is 40-50 F. Storing them in the refrigerator or with temperatures cooler than 40 F will change the flavor and texture of the potato.