Potatoes grow best in loose, well-drained soil (pH 5.0–6.5) at temperatures of 15–20°C, requiring 500–700mm of water over a 90–120 day cycle (FAO). Start with certified seed potatoes (30–50% higher yields than farm-saved seed per CIP), plant 10–15 cm deep and 30 cm apart, and harvest when foliage yellows and skin sets firmly. Potatoes produce more food per unit of water than any other major crop (CIP) and can yield 20–50+ tonnes per hectare commercially or 2–5 kg per plant in home gardens.
In this article (10 sections)▾
What soil do potatoes need?
Potatoes perform best in loose, well-drained, slightly acidic soil with a pH of 5.0–6.5 (FAO). Heavy clay soils cause misshapen tubers and increase disease risk, while sandy soils drain too quickly without amendments. The ideal is a loamy soil rich in organic matter. Before planting, work 5–10 cm of well-rotted compost or aged manure into the top 30 cm of soil (CIP). If your soil is heavy, consider raised beds or container growing.
Avoid planting potatoes where potatoes, tomatoes, peppers, or eggplant grew in the previous two years. These Solanaceae family crops share diseases, especially late blight and common scab, and rotation breaks the disease cycle. A 3–4 year rotation is ideal; 7+ years for certified seed production fields.
How do I choose seed potatoes?
Always start with certified seed potatoes, not supermarket potatoes. Certified seed is inspected for viruses, bacterial diseases, and trueness to type. Farm-saved or grocery store potatoes can introduce diseases that persist in soil for years. In developing countries, certified seed produces 30–50% higher yields than farm-saved seed (CIP). See the Netherlands profile for information on the world's largest seed exporters.
Chitting (pre-sprouting) seed potatoes 2–4 weeks before planting gives them a head start. Place in a cool (10–15°C), bright location with the eyes facing up. When sprouts are 1–2 cm long, they are ready to plant. For larger seed potatoes (over 60g), cut into pieces with at least 2–3 eyes each and let cut surfaces dry for 1–2 days before planting to prevent rot. See our seed saving guide.
When is the best time to plant potatoes?
Planting timing depends on your climate zone. Potatoes need soil temperatures of at least 7–10°C and cannot tolerate hard frost on emerged foliage (FAO). The table below covers every major growing region. For more detail on specific countries, see our planting timing guide.
| Climate Zone | Planting Window | Harvest | Example Regions |
|---|---|---|---|
| Cool temperate | March–April | July–September | UK, Northern Europe, Northern US/Canada |
| Warm temperate | February–March | June–August | Southern US, Mediterranean, Southern Australia |
| Subtropical | October–November | February–March | Northern India, Egypt, parts of South America |
| Tropical highlands | Year-round | 90–120 days after planting | Kenya, Peru, Nepal |
| Double-crop regions | Sep–Oct & Jan–Feb | Two harvests/year | Punjab (Pakistan/India), Nile Delta (Egypt) |
Source: FAO, CIP, USDA Extension Services. Dates are approximate; adjust for local frost dates.
How deep and far apart should I plant potatoes?
Plant seed potatoes 10–15 cm deep with sprouts facing upward. Space them 30 cm apart within the row, with 75 cm between rows (USDA Extension). This gives room for hilling and airflow, reducing disease. In containers or grow bags, plant 3–4 seed potatoes per 40–50 litre bag at 10 cm depth, adding compost as shoots emerge. See our grow bag guide for specific bag sizes.
Hilling is essential: as plants reach 15–20 cm, mound soil around the stems, leaving only the top leaves exposed. This encourages more tuber formation along the buried stem and prevents surface tubers from greening (solanine production). Hill 2–3 times during the growing season.
How much water do potatoes need?
Potatoes need 500–700mm of total water over a 120–150 day crop (FAO), or approximately 25–50 mm per week. They produce more food per unit of water than any other major crop — up to 7 times more efficient than cereals (CIP). The most critical period is during tuber initiation and bulking (6–10 weeks after planting). Irregular watering during this window causes growth cracks, hollow heart, and knobby tubers.
Drip irrigation is ideal: 85–95% water efficiency vs 40–60% for furrow irrigation (FAO). Overhead sprinklers increase foliar disease risk (wet leaves promote late blight). Reduce watering 10–14 days before harvest to promote skin set.
What are the most common potato pests and diseases?
Late blight (Phytophthora infestans) is the most devastating disease worldwide, causing $6+ billion/year in losses globally. The same pathogen caused the Irish Potato Famine. Watch for dark, water-soaked lesions on leaves in cool, wet conditions. Preventive fungicide sprays and resistant varieties (Sarpo Mira, Defender) are the primary defenses.
Colorado potato beetle is the #1 insect pest in temperate regions. Hand-pick in small plantings. For larger areas, Bacillus thuringiensis (Bt) sprays are effective against larvae. Crop rotation and removing volunteer potatoes reduce overwintering populations. The beetle has developed resistance to 50+ insecticides, making rotation essential.
Aphids transmit potato viruses (PVY, PLRV) that reduce yields 20–80%. Use certified virus-free seed, monitor from emergence, and apply insecticidal soap or neem oil early. In commercial production, mineral oil sprays reduce non-persistent virus transmission 40–60%.
Crop rotation is the single most effective cultural practice. Never plant Solanaceae (potatoes, tomatoes, peppers, eggplant) in the same ground more than once every 3–4 years. See our complete diseases and pests guide for full coverage.
How do I know when potatoes are ready to harvest?
Potatoes are ready when foliage yellows and dies back, typically 90–120 days after planting. For new/baby potatoes, harvest 2–3 weeks after flowering. For mature storage potatoes, wait until vines have fully died, then leave tubers in ground for 2 more weeks for skin set (the thumb test: rub skin firmly; if it doesn't peel off, it's set).
Harvest on a dry day when soil temperature is above 7°C (below this, tubers bruise easily). Use a garden fork well away from the plant to avoid piercing tubers. Commercial operations use mechanical harvesters processing entire fields in hours. Expect 2–5 kg per plant in home gardens, or 20–50+ t/ha commercially. US yields average 51 t/ha (FAOSTAT).
How do I store potatoes after harvest?
After harvest, cure potatoes for 10–14 days at 10–15°C with 85–95% humidity (Penn State Extension). Curing heals skin wounds and sets the periderm, dramatically extending storage. Do not wash before storage; brush off soil instead.
| Use | Temperature | Humidity | Duration | Notes |
|---|---|---|---|---|
| Table / fresh market | 2–4°C | 90–95% | 6–9 months | Suppresses sprouting; may cause cold sweetening |
| Seed potatoes | 2–4°C | 90–95% | 6–10 months | Warm to 10–15°C 2 weeks before planting |
| French fry processing | 7–10°C | 95–98% | 4–8 months | Higher temp avoids sugar buildup (dark fries) |
| Chip / crisp processing | 7–10°C | 95–98% | 3–6 months | Low reducing sugars critical (<1.5 mg/g) |
Source: FAO, Penn State Extension, CIP. See our storage and cold chain guide for details.
What are the most common potato growing mistakes?
Waterlogged soil causes rot and creates ideal conditions for late blight. Consistent moisture is key — not constant wetness. Drip is better than overhead.
Planting potatoes in the same spot builds soil-borne diseases (scab, wilt, nematodes) that persist for years. Minimum 3–4 year rotation.
Frost kills emerged foliage and sets growth back weeks. Wait until soil reaches 7–10°C and frost risk has passed.
Blight can destroy an entire crop in days. Monitor weather (cool + wet = high risk) and spray preventively. See our late blight guide.
Uncured potatoes have fragile skin that bruises and stores poorly. The 10–14 day curing period at 10–15°C is essential for storage.
Frequently Asked Questions
How long do potatoes take to grow from seed potatoes?+
Most potato varieties take 90–120 days from planting to harvest. Early varieties (Norland, Kufri Ashoka) can be ready in 70–90 days. Late varieties (Russet Burbank) take 110–150 days. Soil temperature, variety, and climate are the main factors.
Can potatoes be planted in October?+
Yes, in subtropical climates. Northern India, Egypt, Pakistan, and parts of South America plant their main potato crop in October–November for a February–March harvest. In temperate climates (US, UK, Europe), October planting is too late — frost will kill emerged foliage.
How many seed potatoes per 25 gallon grow bag?+
A 25-gallon (100-litre) grow bag can support 4–5 seed potatoes, planted at a depth of 10 cm. Add compost as shoots emerge until the bag is full. Expect 2–4 kg of harvested potatoes per bag depending on variety and care.
What is the best fertilizer for growing potatoes?+
A balanced NPK with emphasis on potassium: approximately 120-60-150 kg/ha of N-P-K for commercial production (FAO). Potassium (K) is the most critical nutrient — it improves tuber size, skin quality, and storage life. Avoid excess nitrogen late in the season.
When is it too late to plant potatoes?+
In temperate climates, planting after mid-June is risky because tubers won't have time to mature before fall frost. In tropical highlands, potatoes can be planted year-round. The rule: ensure 90+ frost-free days after planting.
How deep should I plant potatoes?+
Plant seed potatoes 10–15 cm (4–6 inches) deep with eyes facing up. Space 30 cm apart within the row, 75 cm between rows. In containers, start at 10 cm depth and add soil as shoots emerge (hilling).