Potato

Growing Conditions

Potatoes prefer cool conditions for initial growth and tuber development. They tolerate light frost on young foliage (it may die back but usually regrows) and prefer soil temperatures between 60°F and 70°F for tuber formation. Heat above 80°F causes tuber formation to slow or stop. Full sun is required.

Cold climates: Plant 2–4 weeks before last frost — late April in Zone 5. Choose early, mid, and late-season varieties to extend harvest.

Warm climates: Plant in late winter or early spring for harvest before summer heat. A fall planting is possible in mild climates.

Sowing & Planting

Use certified seed potatoes to avoid introducing disease. Cut large seed potatoes into pieces with 1–2 eyes each; plant small ones whole. Allow cut pieces to dry for 24–48 hours before planting. Plant 4 inches deep, 12 inches apart, in rows 30 inches apart. As plants grow to 8 inches tall, hill soil up around stems, leaving only the top few inches of foliage exposed. Repeat hilling 2–3 times through the season — tubers form along the buried stem.

Care & Maintenance

Water consistently — 1–2 inches per week during tuber formation. Irregular moisture causes hollow heart and knobby tubers. Stop watering when vines begin to die back naturally. Hill regularly to prevent tubers from being exposed to light (greening makes them mildly toxic). No additional fertilizing needed in amended soil; avoid excess nitrogen.

Common Problems

Colorado potato beetle is the primary pest — yellow-and-black striped beetles and their orange larvae defoliate plants rapidly. Hand-pick or use Bt. Late blight is the most serious disease — gray-green water-soaked lesions on leaves that spread quickly in cool, wet conditions. Remove and destroy affected plants; don’t compost. Rotate strictly. Scab causes corky patches on skin — maintain consistent moisture and avoid liming beds before potato planting. Green tubers result from light exposure — hill consistently.

Harvest

For new potatoes (small, thin-skinned): harvest 2–3 weeks after flowering by carefully reaching into the hill and removing small tubers without disturbing the plant. For full-size storage potatoes: wait until vines have died back completely, then leave tubers in the ground for 2 weeks to toughen skin before digging. Cure in a dark, humid location at 50°F–60°F for 2 weeks. Store at 38°F–40°F — properly cured potatoes keep 4–8 months.

Varieties

Early varieties (Red Norland, Yukon Gold) mature in 70–80 days and are good for new potatoes and fresh eating. Mid-season varieties (Kennebec, Red Pontiac) mature in 80–100 days. Late/storage varieties (Russet Burbank, Katahdin) mature in 100–120 days and store longest. Fingerling types (Russian Banana, French Fingerling) are specialty varieties with excellent flavor. For Zone 5 home gardens, Yukon Gold is a reliable all-purpose choice.