Vegetable · Solanaceae
Potato
Solanum tuberosum
A humble bed of cut tubers, hilled and watered through the season, becomes a pantry that carries the household into winter.
Full sun
Every 3–7 days
50–77°F · 10–25°C
70–120 days
Overview
The potato is a cool-season crop with a long lineage, a nightshade in the same family as the tomato and pepper. Its roots run back to the Andes, where it fed communities for thousands of years before it found a place on tables around the world. The prize is the tuber, a swollen underground stem the plant packs with starch, and though it grows in the dark it is no root.
The real work of the potato happens quietly beneath the surface, out of view of the garden's daily rhythm. Cut pieces of seed potato go into the ground, each with an eye, and leafy stems rise while tubers form on short shoots below. The season's defining ritual is hilling, mounding soil up the stems to keep the young tubers buried and in the dark, since any tuber that meets the light turns green and bitter.
Set into loose, fertile, faintly acidic ground with even water once the tubers form, even a modest patch keeps a kitchen supplied for months. Because the crop stores so gracefully, a single autumn harvest becomes a full larder that carries a household well into winter. There is a certain quiet satisfaction in a bin of potatoes standing ready through the cold season.
Care
The short version: potatoes want full sun, loose slightly acidic soil rich in organic matter, and even moisture once the tubers begin to form. Feed at planting, keep the nitrogen restrained, and hill soil up the stems through the season for a crop that earns its place in the pantry.
Light
Potatoes ask for full sun, ideally 6 or more hours of direct light a day, and they repay a bright, open position with a fuller crop. They will tolerate partial sun, but the tops grow weaker and the tubers stay smaller, so give them the most generous stretch of light the garden offers.
Water
Keep the soil evenly moist, roughly 1 to 2 inches of water a week, and hold that rhythm steady once the tubers begin to swell. Avoid letting the ground sit waterlogged, since soggy soil invites rot and disease. A calm, consistent watering routine suits them far better than extremes.
Soil
Give potatoes loose, well-drained sandy loam enriched with organic matter, on the acidic side at a pH of 5.0 to 6.0, which also helps keep scab at bay. The open, crumbly texture matters as much as the fertility, since it lets the tubers swell freely into a well-formed crop.
Temperature
The potato is a creature of cool weather, most content between 50°F and 77°F (10°C to 25°C). As the heat of summer climbs, tuber growth slows, which is why an early start suits the crop and lets it do its best work before the warm months arrive.
Humidity
Ordinary outdoor humidity is all the potato asks, so there is no figure to chase. What earns attention instead is airflow, since damp, crowded foliage is precisely the setting late blight favors. A little breathing room between plants keeps the whole bed healthier.
Feeding
Work a balanced fertilizer into the bed at planting, then offer a modest side-dressing of nitrogen as the plants emerge and the hilling begins. Restraint is the elegant choice here, since too much nitrogen produces lush foliage at the expense of the tubers that make the crop worth growing.
Pruning
The potato asks for no real pruning, a quiet virtue in a busy garden. Simply remove diseased foliage as soon as it appears, and keep hilling soil up the stems to bury the developing tubers and spare them the greening that light brings on. That steady mounding is the season's main gesture of care.
Size & spacing
Plants rise 1 to 3 feet (30 to 100 cm) tall and spread 12 to 24 inches (30 to 60 cm) across, an unassuming presence in the bed. Give each one room and mound the soil generously, because that buried space is where the season's real reward quietly takes shape.
When to plant
The potato belongs to the early garden, going in while the ground is still cool and the season young. Settle the seed pieces into place 2 to 4 weeks before the last frost, once the soil has reached around 45°F to 50°F (7°C to 10°C). From there the rhythm carries forward: a first taste of new potatoes at midsummer, then the main storage crop lifted in fall once the tops have died back.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Early spring, about 2-4 weeks before the last expected frost once soil reaches roughly 45-50°F
- Harvest: Harvest new potatoes about 60-70 days after planting; harvest mature storage potatoes about 90-120 days after planting once tops die back
Hardiness
USDA hardiness zones: 3–9
Temperature: down to -40°C
Troubleshooting
For all its easy reputation, the potato has a short list of troubles worth knowing, and they tend to appear either on the foliage during the growing season or on the tubers at harvest. Recognizing the few that matter turns worry into a simple response. Match what the garden shows below, then act while it still counts.
Dark, oily blotches and foliage that collapses in wet spells
The trouble here is late blight, the same Phytophthora that undoes tomatoes, and it can sweep a bed after a cool, damp stretch. On humid mornings, look to the leaf undersides for brown-black lesions edged in pale margins and dusted with white. The response is decisive: pull and destroy affected plants at once, keep them well away from the compost, and set aside any rotted tubers before they reach storage.
Fix:
- Remove and destroy infected plants immediately
- Do not compost infected material
- Apply an approved fungicide preventively where blight is present
- Harvest carefully and cull infected tubers before storage
Striped beetles and red grubs working through the foliage
The Colorado potato beetle is the crop's most notorious visitor, and a heavy showing can leave a plant stripped. Turn the leaves and look for orange egg clusters, soft red larvae, and the adults marked with ten black stripes. The remedy is unglamorous but effective: handpick them into soapy water, drape row cover over young plants, and shift the planting to fresh ground each year.
Fix:
- Handpick adults, larvae, and egg masses into soapy water
- Use row covers early in the season
- Apply an approved insecticide if infestation is heavy
- Rotate planting location yearly
Green-skinned tubers with an edge of bitterness
A tuber greens wherever light reaches it near the surface, and that green tissue carries solanine, the toxin that leaves a potato bitter and unfit for the plate. The usual culprit is thin hilling that left the tubers exposed. Mound soil over them as the plants grow, discard any that have greened heavily, and store the harvest somewhere cool and dark.
Fix:
- Hill soil up over exposed tubers as plants grow
- Discard heavily greened tubers
- Store harvested potatoes in cool, dark conditions
- Cut away minor green areas before cooking
Rough, corky patches roughening the tuber skins
Those corky patches are common scab, a soil bacterium that surfaces when the ground dries during tuber set or the pH runs high. A single peeled tuber tells the story: the marks stay shallow and the flesh beneath is sound, so the harvest remains perfectly good at the table. Keep the soil evenly moist as the tubers form, hold the pH down around 5.0 to 5.5, and leave the fresh manure aside.
Fix:
- Maintain even soil moisture during tuber formation
- Keep soil pH slightly acidic (around 5.0-5.5)
- Plant scab-resistant cultivars
- Avoid fresh manure and alkaline amendments
Toxicity
There is a clean line to draw with this plant: the cooked tuber is a safe, everyday pleasure at the table, while the rest of it is not. The foliage, stems, sprouts, and any green or raw potato carry a natural toxin called solanine that can sicken people and animals alike. Trim away green spots, discard badly greened tubers, and keep the vines and sprouts out of reach of pets, livestock, and children.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Caution
A cat that chews the leaves, stems, or a green sprouted tuber takes in solanine, and drooling and vomiting tend to come first, with diarrhea and low energy soon after. A larger dose can reach the heart and nervous system, so a call to the vet is wise if more than a nibble was taken.
Dogs Caution
Dogs that dig up and gnaw raw or green tubers, or browse the foliage, usually show an upset stomach, loose stools, and a subdued mood. Keep a watchful eye, since heavier amounts of glycoalkaloid can affect the heart rhythm.
Horses Caution
The vines and any green or sprouted potatoes are no place for a horse. Solanine brings on colic, drooling, and a dull, unsteady stance, and a horse grazing fallen foliage may take in enough to warrant the vet.
Rabbits Caution
Leaves, stems, and green tubers should stay well away from rabbits, whose small size means even a little solanine causes real harm. A poor appetite, a bloated belly, and weakness are the signs to watch for if any is eaten.
Livestock Caution
Cattle, sheep, pigs, and goats can be poisoned by discarded vines or piles of green and cull potatoes left in the field. The solanine sets off digestive upset, joined by staggering and trembling once enough accumulates.
Birds Caution
Chickens and other birds should be kept from the foliage, sprouts, and any greened scraps, all of which hold solanine. A little plain cooked potato does them no harm, but the green, raw parts do.
People Cooked tuber safe
A cooked, properly stored potato is a safe, everyday staple of the table. The hazard lies only in the green skin, the sprouts and eyes, and all the foliage and stems, which carry solanine that turns a potato bitter and can cause illness, so cut away green spots, discard any badly greened tuber, and keep the vines off the plate.
Cooked, properly stored potato tubers are a safe food. The hazard is the foliage and any green, raw, or sprouted tubers, which contain solanine.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Hundreds of potato varieties exist, distinguished mostly by skin color, the character of the flesh, and the dishes they suit. The four below are the familiar names that fill most gardens and grace most kitchens.
Yukon Gold
Yukon Gold, a thin-skinned yellow potato with buttery, all-purpose flesh, has quietly become the standard the kitchen reaches for.
Russet Burbank
Russet Burbank, large and oblong with brown skin, carries so much starch that it remains the classic choice for baking and frying.
Red Pontiac
Red Pontiac, red-skinned and white-fleshed, is prized for its dependable yields and the grace with which it keeps in storage.
Kennebec
Kennebec, a vigorous white potato, crops generously and shrugs off more disease than most, an easy companion for any kitchen garden.
Companions
Potatoes do well beside nitrogen-fixing beans and a few traditional partners, and badly beside their nightshade relatives and sprawling vines that crowd them and trade diseases.
Plant near
Bush beans: Legumes fix nitrogen and are reported to help repel some potato pests.
Corn: Traditional companion that does not compete heavily and shares no major potato diseases.
Cabbage-family crops: Generally compatible bed companions that do not share potato's key diseases.
Horseradish: Often planted near potatoes and is said to improve overall plant vigor and pest resistance.
Keep apart
Tomato: Another solanaceous crop that shares late blight and other diseases, increasing risk to both.
Cucumbers and squash: Sprawling cucurbits crowd potatoes and can increase disease pressure.
How to propagate
Two paths lead to a potato crop, though for nearly every gardener the choice all but makes itself.
Bulbs & cormsEasy
Early spring, 2-4 weeks before the last frost · Sprouts emerge in about 2-4 weeks after planting
Nearly every gardener starts potatoes from certified seed-potato pieces, each cut to carry one or two eyes and left to cure for a day or two before planting. They go into the ground in early spring, 2 to 4 weeks before the last frost, about 4 inches deep, with sprouts breaking the surface in roughly 2 to 4 weeks. From there the season's rhythm is simply to keep mounding soil up the stems as the plants climb.
SeedDemanding
Indoors in late winter · Several weeks to germinate and grow on before transplanting
Starting from true botanical seed is a more exacting undertaking, sown indoors in late winter and grown on for several weeks before it can be transplanted. Because the offspring emerge so variable, home gardeners seldom take it up, and the method remains largely the province of breeders.
Myths
The whole potato plant must be edible, given how central the tuber is to the table.
Only cooked tubers, stored well and never greened, belong on the plate. The foliage, stems, sprouts, and any green or raw tuber carry solanine, which is genuinely toxic, so the plant as a whole is no open invitation. Enjoy the tuber with confidence, and leave the rest of the plant in the garden.
Potatoes must be raised from true seed, the way most vegetables are.
In practice, nearly every gardener plants certified seed-potato pieces, each cut to carry one or more eyes. True botanical seed rarely leaves the breeder's hands, since it yields a mixed and unpredictable set of offspring. A few good seed potatoes are all it takes to begin a crop worth keeping.