Potato

Solanum tuberosum

Days to maturity are calculated from date of direct seeding.

Culture
• Potatoes prefer fertile, loose, well-drained soil
• Forking beds is recommended
• Apply a fertilizer that is low in nitrogen and high in phosphorus such as bone meal — use 5-7 pounds per 100 square feet
• Proper soil pH of 5.2-6.0 will help avoid scab
• Irrigate thoroughly when needed, allow the soil to dry out somewhat before watering again
• Hilling: as plants grow, cover with soil, mulch, or compost, while leaving top-growth exposed
• Repeat hilling process 3-4 times throughout season

Direct Sowing
• Plant potatoes up to 3 weeks before your last frost date
• Larger potatoes can be cut into smaller pieces to use as seed — allow the cut potato to heal before planting to prevent rot (2-3 days at 70°F)

Insects & Diseases
• Common insects: Colorado potato beetle, tuber flea beetle, potato aphid, potato psyllid, potato tuber worm/moth
• Insect control: Pyrethrin and row covers
• Common diseases: Early and late blight, white mold, botrytis, leaf roll virus, mosaic virus, verticilium wilt, potato scab
• Disease prevention: 4-year crop rotation, and fungicide applications

Harvest & Storage
• "New" potatoes can be harvested from early varieties beginning 60 days after planting
• Standard potatoes yield about 10 times the amount originally planted
• Fingerling potatoes yield 15-20 times the amount originally planted
• Potatoes can be harvested based on your preferred size, but you want to be mindful not to keep them in the soil too long as it may lead to an increase in insect damage or disease. You may want to dig up a test plant to check for maturity. Skins should remain in place when rubbed
• Early potatoes can be harvested while the plant is still flowering, while main crop potatoes should be harvested when the foliage is dying back at the end of the growing season. Once top-growth dies down, leave in the ground for 2 weeks and then harvest
• Potatoes should be harvested on dry days when the soil is dry; if you are unable to avoid harvesting when the soil is wet, allow the potatoes to air dry before storing in bags or containers. If the soil is dry, freshly harvested potatoes can be left on the soil for a few hours (no longer) to allow time to dry down
• Use a fork to loosen the soil, starting at the edge of the plant and working in, being mindful not to damage the tubers. Lift the plant carefully to expose the tubers, and make sure to check the soil for any additional potatoes
• Stop watering around mid-August to help prepare the potatoes for storage
• Toss out any potatoes with substantial greening, bruises, damage, or disease
• Check stored potatoes regularly, removing any potatoes that are starting to go bad
• Once dry, cure potatoes by removing excess soil, but do not wash until ready to eat. Store in mesh/breathable bags, sturdy boxes, crates, etc. in a cool, dark place
• Potatoes should be stored in a cool (40-45°F), dry place with 90% relative humidity. The area should be somewhat humid to prevent the tubers from drying out too much and should have no light as light can cause greening. Cellars are the perfect location if available. Ensure the location has air flow and ventilation, and do not store in airtight containers