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Potato

Solanum tuberosum

VegetableRootBeginner Easy

Forgiving and productive from certified seed potatoes. Hill soil over the tubers so they don't green and turn toxic, and grow them in acidic soil — never lime the bed.

Growing conditions

Light
Full sun — at least 6–8 hours of direct sun a day
Water
Medium
Soil
Loose, well-drained, fertile loam rich in organic matter; avoid heavy, compacted, or waterlogged soil, which causes misshapen tubers and rot · pH 5.0–6.5 (slightly acidic). Extension consensus favors the lower end: where common scab is a problem, hold pH between 5.0 and 5.3 (some sources allow 4.8–5.8). Do NOT lime potato ground — sweet, near-neutral soil encourages scab.
When to sow
Plant 2–3 weeks (14–21 days) before your average last spring frost. Sprouts emerging above ground are frost-tender, so if a late frost threatens after they break through, hill soil over them or cover overnight. In the hot South, plant in late winter, or grow a fall crop.
Spacing
25–30 cm (10–12 in) between seed pieces in the row, rows 76–91 cm (30–36 in) apart. Space closer (~20–23 cm / 8–9 in) for many small 'new' potatoes, wider (~38 cm / 15 in) for fewer large storage tubers.
Days to maturity
Early/first early ~60–90 days; mid-season/maincrop ~90–110 days; late ~110–135 days (a few storage types run to 160). 'New' potatoes can be dug even earlier, soon after flowering.
Hardiness
Grown as a spring/summer annual across USDA zones 3–11. Cool, frost-free spring weather suits them best; in cold zones (3–6) plant in spring after the soil warms, while in the hot South (8–11) plant very early (late winter) so tubers bulk up before summer heat, or plant a fall crop. Tubers stop forming once soil tops about 27–30°C (80–85°F).

How to grow it

  1. 1

    Start with certified seed and chit it

    Buy certified (disease-free) seed potatoes — grocery-store spuds are often treated to resist and can carry disease. A few weeks before planting you can chit (pre-sprout): set the tubers eyes-up in a single layer somewhere warm (~21°C / 70°F) and bright but out of direct sun, until short, stubby green sprouts form. Chitting gives stronger emergence and can pull harvest forward by a week or two.

  2. 2

    Cut, cure the pieces, then plant

    Cut larger tubers into blocky 40–60 g (1.5–2 oz) pieces, each with at least one eye; plant small tubers whole. Let cut pieces (callus over) for 2–3 days in a humid 15–21°C (60–70°F) spot before planting — this skin prevents rot. Plant 8–10 cm (3–4 in) deep, cut side down, 25–30 cm (10–12 in) apart, once soil is at least 7–10°C (45–50°F).

  3. 3

    Hill (earth up) as the plants grow

    When stems are about 15–20 cm (6–8 in) tall, hill them: pull loose soil (or pile straw ) up around the stems, leaving the top few leaves exposed. Repeat once or twice more through the season. , also called earthing up, gives tubers room to form, keeps roots cool, and — most importantly — keeps developing tubers covered and in the dark so they don't turn green.

  4. 4

    Water deeply and evenly

    Potatoes need steady moisture, about 2.5 cm (1 in) of water per week, especially once they flower and tubers are bulking up. Deep, even watering produces smooth, well-shaped tubers; a dry-then-soaked cycle causes knobby, cracked, or hollow potatoes. with straw to hold moisture and keep the soil cool.

  5. 5

    Feed modestly and avoid excess nitrogen

    Work into the bed before planting and moderately. Potatoes are moderate feeders; too much nitrogen drives lush vines but few tubers. A balanced feed at planting and a light side-dress as plants establish is plenty. Skip the lime — keeping the soil on the acidic side helps suppress scab.

  6. 6

    Scout for pests and blight weekly

    Check plants every few days. Hand-pick orange-and-black Colorado potato beetles, their humpbacked larvae, and their orange egg clusters on leaf undersides. Watch foliage in cool, wet spells for the dark, water-soaked lesions of late blight. Rotate where you plant potatoes each year and keep them well away from tomatoes — as companions they share the same diseases, so pairing them backfires.

  7. 7

    Harvest, then cure for storage

    Dig 'new' potatoes a couple of weeks after flowering for immediate eating. For storage potatoes, wait until the vines have died back, then dig carefully. the tubers for about 2 weeks in the dark at 7–15°C (about 45–60°F) with high humidity so cuts heal and skins thicken, then store cool and dark.

Gardener's notes

  • Always start with certified seed potatoes, not grocery-store spuds — store potatoes are often -inhibited and can introduce disease to your soil.
  • Chitting (pre-) the tubers in a warm, bright spot before planting gives a faster, more even emergence and can move harvest up by a week or two.
  • storage potatoes for about two weeks before putting them away — that healed, thickened skin is the difference between spuds that keep for months and ones that rot. And remember: green tubers contain toxic solanine, so keep them buried (hill!) and store them in the dark.

Varieties worth knowing

Yukon Gold (early)
Yellow-fleshed, buff-skinned all-purpose favorite, ~80–90 days. Relatively determinate/early — sets tubers in one main layer near the seed piece, so it needs less aggressive hilling.
Red Norland / Dark Red Norland (early)
Smooth red skin, white flesh, ~70–90 days. Excellent early 'new potato'; early types are typically determinate.
Kennebec (mid-season)
Buff skin, white flesh, heavy yields, ~90–100 days; good all-purpose and some blight tolerance.
Red Pontiac (mid-season)
Vigorous, red-skinned, tolerant of heavy soils and warmth — a solid Southern pick, ~90–110 days.
Russet Burbank (late)
Classic baking/storage russet, ~110–120+ days. Indeterminate — keeps setting tubers up the buried stem, so it rewards generous hilling; needs a long season.
Katahdin (late)
Dependable late storage variety, ~100–120 days; widely adapted and a good keeper.

Common problems & fixes

Late blight (Phytophthora infestans)
Sign: Dark, water-soaked greasy patches on leaves and stems, often with white fuzzy growth on the undersides in humid weather; tubers develop reddish-brown dry rot. Spreads explosively in cool, wet conditions.
Fix: This is the disease behind the Irish Potato Famine and it can destroy a crop fast. Plant certified seed, space for airflow, water at the base (not overhead), and remove volunteer potatoes. Keep potatoes away from tomatoes — they share it. Remove and destroy infected plants; do not compost them.
Colorado potato beetle
Sign: Rounded yellow-and-black-striped adult beetles, plump reddish humpbacked larvae, and bright orange egg clusters under leaves; rapid, ragged defoliation.
Fix: Hand-pick adults and larvae and crush the egg masses — most effective early. Rotate crops (don't plant potatoes where any nightshade grew last year) and mulch with straw, which hampers the beetles. Potatoes tolerate some leaf loss, but protect plants once tubers start forming.
Common scab (high pH)
Sign: Rough, corky, raised or pitted brown patches on the tuber skin. Cosmetic — the potato is still edible once peeled — but unsightly.
Fix: Worsens in sweet (alkaline) soil and dry conditions. Keep pH on the acidic side (around 5.0–5.3), do NOT add lime, keep soil evenly moist during tuber set, plant scab-resistant varieties, and never add fresh manure, which feeds the disease.
Greening / solanine (toxic)
Sign: Green patches on the skin and just under it, from light exposure either in the garden (uncovered tubers) or in storage.
Fix: Green skin signals a buildup of solanine, a bitter, genuinely TOXIC glycoalkaloid — green tubers can cause headaches, cramps, and nausea, and should not be eaten. Cut away and discard green parts (badly greened tubers entirely). Prevent it by hilling so tubers stay buried and by storing potatoes in the dark.
Hollow heart / knobby tubers
Sign: An internal cavity or brown center when cut, or lumpy second-growth tubers.
Fix: Caused by uneven growth from inconsistent watering or a rapid spurt after drought. Water deeply and evenly, mulch to steady soil moisture, and don't over-fertilize with nitrogen.

Companions

Grows well with
Beans (bush)CornPeasHorseradish (said to deter pests)MarigoldsCabbage-family greens (some traditions)
Keep apart from
Tomatoes and other nightshades (eggplant, peppers) — shared late blight and pestsCucurbits like squash and pumpkins (compete and share blight pressure in some guides)Carrots and other root crops that compete in the same soil layerSunflowers

Harvest & storage

Harvest
For tender 'new' potatoes, gently dig around the plant about 2–3 weeks after it flowers and take a few small tubers, leaving the rest to grow. For mature storage potatoes, stop watering and wait until the vines have yellowed and died back, then dig on a dry day, lifting carefully with a fork well away from the stem to avoid spearing tubers. If skins still rub off, leave the crop another week or two to mature.
Storage
Don't wash storage potatoes — brush off soil. Cure them first for about 2 weeks in the dark at 7–15°C (45–60°F) with high humidity (85–95%) so cuts heal and skins toughen. Then store long-term in the dark at 4–7°C (40–45°F) with high humidity and good ventilation. Keep them out of all light to prevent greening, and away from apples (the ethylene encourages sprouting). New potatoes have thin skins, don't cure, and should be eaten within a few days.

Sources

This guide is curated from authoritative horticulture references — primarily US university Extension services, the USDA, and the RHS.