How to grow potato
Family Solanaceae. Hardy to USDA hardiness zone 3a+ (U.S. Department of Agriculture). Full sun. Ready in 70-120 days.
Sun
Full sun
Spacing
12 in
Days to harvest
70-120 days
Hardiness
Zone 3a+
What growers actually recorded
Loading zone 7b results…
When to plant potato
- Direct sow: ~-2 weeks after last frost.
Companion plants for potato
Plant with: Bean, Corn, Marigold.
Avoid near: Tomato, Cucumber.
Common pests & problems
Colorado potato beetle. Handpick daily.
Feeding & fertilizer
N-P-K ratio: Low N (5-10-10) once fruiting starts
Organic options: Compost 2-3 in. at planting · Fish emulsion every 2 wks while young · Bone meal + kelp at flowering for calcium/potassium
When to feed: Compost at planting → light nitrogen through vegetative → switch to P/K when flowers appear.
Watch for: All leaves, no fruit = too much N. Blossom-end rot = calcium deficit + uneven watering.
N = nitrogen (leaves), P = phosphorus (roots and flowers), K = potassium (fruit and disease resistance). How to read a fertilizer label →
Grower's tip
Hill soil up around stems as plants grow. Every buried inch of stem produces more tubers.
When to plant potato in your zone
Free month-by-month sowing and transplanting lists, built from frost dates for your USDA (United States Department of Agriculture) hardiness zone.
Soil & water for potato
Soil & pH
6.2-6.8: slightly acidic
Loose, deep loam. Break up compaction 12 in down; tomatoes and peppers root deeply when given the room.
Work 2-3 in of compost + a handful of bone meal per plant into the hole. Warm soil to 60°F+ before transplanting; black plastic mulch 2 weeks ahead helps in the North.
Watering
1-1.5 in / week, more in fruit set
Deep soak at the base twice a week. Drip or soaker hose beats overhead watering: wet leaves invite early blight.
Stick your finger 4 inches in near the stem. If it's dry at the second knuckle, water. If it's still damp, wait. Flipping from bone-dry to soaked is what cracks fruit and brings on blossom-end rot.
Knowing when to harvest
- New potatoes: 2-3 weeks after flowering, dig gently for tender skin.
- Storage potatoes: tops fully die back; wait 2 weeks after for skins to set.
- Cure at 55-60°F, 85% humidity for 10-14 days before storing.
Storing & keeping
Cool (38-45°F), dark, humid (85%), well-ventilated. 4-6 months for storage varieties. Never refrigerate below 38°F (starch converts to sugar, bad flavor & carcinogens when fried).
What to expect
Per plant: 3-5 lb from a seed piece; 10 lb from a bag-grown Yukon Gold in a good year
Troubleshooting potato
Green skin on tubers
Likely cause: Sun exposure. Contains solanine, mildly toxic
What to do: Hill soil or mulch 6+ inches over developing tubers; cut off green portions before eating.
Hollow heart
Likely cause: Rapid growth after drought
What to do: Steady water: 1.5 in / week.
Scab (rough patches)
Likely cause: Soil pH above 6.5 or dry conditions during tuber formation
What to do: Keep pH 5.2-6.2 for potatoes; maintain moisture during tuber set.
Varieties worth growing
Yukon Gold (early)
Golden flesh, all-purpose, stores well.
Kennebec (main-crop)
Blight-tolerant and high-yielding. The market grower's standard.
Purple Majesty
Anthocyanin-rich; keeps color when cooked.
Growing potato in containers
Grow bags 15-20 gallon, one seed piece per 3 gallons of soil. Add soil as vines grow (hilling in a bag).
Nutrition
High in lycopene (tomato), capsaicin (hot pepper), vitamin C, and potassium.
Common questions
Can I plant grocery-store potatoes?
Not recommended. Most are sprayed with sprout inhibitors and may carry diseases. Buy certified seed potatoes.
How long can I leave potatoes in the ground?
2-3 weeks after tops die back is ideal. Beyond that, slugs and wireworms find them.
Where these numbers come from
- USDA Plant Hardiness Zone Map (2023 revision). Zone assignment and the 30-year normals behind every cold-hardiness figure.
- NOAA NCEI 1991-2020 Climate Normals. Frost dates, growing-season length, and the probability bands on both.
- Cornell, UMN, and UC Davis Cooperative Extension crop guides. Spacing, days to maturity, soil pH targets, and per-plant yield ranges.
- USDA FSIS / FDA Produce Safety guidance. Wash, cure, and cold-storage handling numbers.
Ranges are regional guidance, not a promise for your yard. Your own logged results always override the published range.