How to Grow Potato

Growing guide

Overview

Potatoes are a productive beginner crop grown from certified seed potatoes in garden beds, bags, or barrels. They need full sun, loose well-drained soil, and consistent moderate moisture to produce edible tubers in about 70-120 days. Keep the tubers covered, because green potato skin and plant parts contain toxic solanine.

Soil & planting prep

Potatoes need loose, well-drained loamy or sandy soil with a pH between 5.0 and 6.5. Work in compost and loosen the soil 8-10 inches deep before planting, but avoid fresh manure and high-nitrogen amendments. Plant seed pieces 4-6 inches deep and 12 inches apart, with rows 30-36 inches apart.

When to plant

Plant potatoes after the last spring frost date, once the soil has warmed to at least 45°F. Potato foliage is not frost-tolerant, so do not rush plants into cold, wet spring soil. In most North American zones, this means planting in spring after the danger of hard frost has passed.

How to plant

1. Start with certified seed potatoes, not grocery-store potatoes, and cut large tubers into pieces with 1-2 eyes each; let cut surfaces cure for 24-48 hours.
2. Loosen the soil to 8-10 inches deep and mix in compost, avoiding fresh manure.
3. Plant seed pieces cut-side down 4-6 inches deep and 12 inches apart, with rows 30-36 inches apart.
4. Water moderately after planting to keep soil moist but not soggy.
5. When plants reach 6-8 inches tall, hill soil or straw around the stems to cover lower leaves and keep forming tubers dark.

5 common mistakes to avoid

• Planting grocery-store potatoes: they may carry diseases or be treated with sprout inhibitors, so always use certified seed potatoes.
• Planting too early in cold, wet soil: seed pieces can rot before they sprout; wait until after the last frost date and soil is at least 45°F.
• Skipping hilling: tubers exposed to sunlight turn green and develop toxic solanine, so hill soil or straw over stems when plants are 6-8 inches tall.
• Overfeeding nitrogen or using fresh manure: this pushes leafy top growth at the expense of tubers, so use compost and balanced fertility instead.
• Watering erratically during tuber bulking: dry-wet swings cause knobby, cracked, or hollow tubers; keep moisture consistent from flowering until vines yellow.

Harvesting & storage

For new potatoes, dig gently about 2-3 weeks after plants flower. For full-size storage potatoes, wait until the vines yellow and die back, then loosen soil from the edge with a digging fork to avoid piercing tubers. Cure harvested potatoes in a cool, dark, humid place for 1-2 weeks, then store them in a dark, well-ventilated spot around 40-45°F.

Companion planting

Good companions include beans, corn, cabbage, and marigolds. Avoid planting potatoes near tomatoes, peppers, or eggplants, which share soil-borne diseases and pests.

Growing in containers

Potatoes grow well in a 10-gallon grow bag, pot, or barrel. Plant one or two seed pieces per 10-gallon container, start with 4-6 inches of soil, and add soil or straw as the vines grow.

Pro tips

Plant certified seed potatoes after last frost. Hill soil up around stems as they grow to increase yield. Harvest after plants die back. Never eat green potatoes — solanine is toxic.