How Are Potatoes Produced? From Planting to Harvest

Potato production is a multi-stage process that begins not with a seed in the traditional sense but with a piece of tuber, and it ends months later with a harvest that demands careful timing and handling to avoid damaging the crop. Between planting and pulling potatoes from the ground, growers manage a surprisingly sensitive plant whose yield depends on soil temperature, day length, water precision, disease pressure, and a well-timed decision about when to kill the vine. Every cultivated potato traces its ancestry to wild species native to the Andes of southern Peru, and the crop’s quirks reflect that highland origin in ways that still shape how it is grown worldwide.

Where Seed Potatoes Come From

Potatoes are not typically grown from botanical seed. Instead, growers plant small whole tubers or cut pieces of tubers, each containing at least one “eye” (a dormant bud). These are called seed potatoes, and their quality matters enormously because any virus or disease present in the seed tuber gets passed directly to the next generation. To break that cycle, the commercial seed potato supply chain starts in a laboratory. Tissue culture techniques produce virus-free plantlets, which are then multiplied through cuttings and mini-tubers before eventually reaching the field as certified seed stock.

¹

This system exists because potatoes reproduce clonally. Every plant grown from the same tuber is genetically identical, which means a single pathogen can sweep through an entire crop if the starting material is infected. The tissue-culture pipeline, which moves from lab-grown plantlets to greenhouse mini-tubers to field-multiplied seed over several generations, is the industry’s main defense against that vulnerability. Genetic analysis has confirmed that all cultivated potatoes descend from a single domestication event among wild species in Peru, and the crop’s genetic diversity has been shaped by thousands of years of selection followed by more recent introgressions from wild relatives.

²

Chitting and Breaking Dormancy

Before seed potatoes go into the ground, many growers put them through a process called chitting, or pre-sprouting. The idea is to wake the tuber from dormancy and encourage short, sturdy sprouts so the plant gets a head start once planted. In practice, this means holding seed tubers in a lit, cool environment for several weeks. Light exposure keeps sprouts compact rather than long and spindly, which matters both for mechanical planting and for early growth vigor once they reach the field. Research has found that even modest daily light exposure strongly inhibits excessive sprout elongation and accelerates emergence compared to tubers planted without any pre-sprouting treatment.

³

The duration of chitting also affects how the crop develops. Longer pre-sprouting periods physiologically age the seed tuber, leading to more sprouted eyes, more stems per plant, and ultimately more tubers. That accelerated growth translates into fewer days to emergence, earlier tuber formation, and higher harvest index, which is particularly useful in short-season environments where the growing window is tight.

⁴

Growers in tropical regions sometimes use a different approach. In Kenya, researchers found that covering seed tubers with natural materials like grass or banana leaves produced more vigorous sprouts and substantially larger tubers than either chemical growth regulators or untreated controls. Chitted seed tubers covered with natural materials yielded tubers roughly two and a half times larger than those from unchitted controls, showing that even low-tech dormancy-breaking methods can make a large difference in yield.

⁵

Planting and Soil Conditions

Soil temperature at planting is a hard constraint. Potatoes will not emerge when the soil is too cold; early research showed that plants failed to emerge at soil temperatures around 48°F (about 9°C).

⁶

Most growers wait until soil has warmed to at least 45–50°F at a four-inch depth before planting, though the exact threshold varies by cultivar. The tubers are typically placed in furrows or ridges about three to four inches deep and roughly a foot apart within the row, with rows spaced wide enough for equipment to pass through later.

Hilling, the practice of mounding soil around the base of the growing plant, is standard in most potato systems. It serves several purposes: covering developing tubers to prevent them from turning green from light exposure, improving drainage, and suppressing weeds. Interestingly, field trials with transplanted seedlings from hybrid true potato seeds found that hilling did not increase total tuber yield, though it could shift the size distribution of the tubers produced.

⁷

For conventional seed-piece planting, however, hilling remains nearly universal because the risk of green, unmarketable tubers is too high without it.

How Tubers Form Underground

Tuber formation, or tuberization, is one of the more fascinating parts of potato biology. Once the plant is established and growing above ground, underground stems called stolons begin to elongate horizontally. At some point, the tips of those stolons swell and start accumulating starch, forming the tubers you eventually harvest. The signal to begin that swelling is driven largely by day length and hormones.

Many potato species evolved in the Andes near the equator, where days and nights are close to equal length. Short photoperiods promote tuberization, and the key hormonal mechanism involves gibberellins. Gibberellins are growth hormones that encourage stem elongation and actively inhibit tuber formation. When days shorten, gibberellin levels in the stolons drop, and that drop is part of what allows tubers to initiate.

⁸

Genetic studies have confirmed that specific genes controlling gibberellin metabolism significantly influence when tuberization occurs. Plants engineered to produce more gibberellins in leaves actually tuberized earlier under short days, while those overproducing gibberellins specifically in the tubers showed delayed tuber formation, highlighting how location-specific hormone signaling within the plant controls the process.

⁹

Modern commercial cultivars have been bred to tuberize under longer day lengths common in temperate growing regions. Genomic studies have traced part of this adaptation to a specific locus that controls plant maturity, where wild-species introgressions provided the genetic variants that enabled potatoes to be grown far from the equator.

¹⁰

Water Management During the Growing Season

Potatoes are thirsty and unforgiving when it comes to water stress. Their root systems are shallow compared to most field crops, which means they draw moisture from a narrow band of topsoil and can run into trouble quickly during dry spells. Insufficient irrigation can cut yield by up to half and cause defects like misshapen tubers, hollow heart, and vascular necrosis that make them unsaleable.

¹¹

But over-watering is almost as damaging. Saturated soil promotes root diseases and can cause tubers to crack or develop lenticels that invite pathogens in storage. The general recommendation from soil-based scheduling methods is to keep soil moisture between about 80 and 90 percent of field capacity through the growing season. That is a narrow target, and hitting it consistently requires either careful scheduling based on weather data and soil sensors or a grower’s practiced intuition backed by years of experience with a particular field.

Water management also intersects with harvest quality. Pre-harvest irrigation of dry soils, as we will see later, can reduce physical damage during the harvest itself.

Disease and Pest Pressure

Late blight, caused by the organism Phytophthora infestans, is the most historically notorious potato disease and remains a persistent threat. It was the primary driver of the Irish Potato Famine in the 1840s and continues to demand significant fungicide inputs worldwide. Modern forecasting models have made it possible to time fungicide applications more precisely. In southern India, integrating weather-based blight forecasting with targeted spraying reduced fungicide applications by a third to nearly half compared to calendar-based spraying schedules, without sacrificing disease control or yield.

¹²

Soilborne diseases are another constant concern. Common scab, Rhizoctonia canker, black scurf, and Verticillium wilt all build up in soils where potatoes are grown repeatedly. Crop rotation is the primary non-chemical tool for managing them. Rotating with canola or rapeseed has been shown to reduce the severity of Rhizoctonia canker, black scurf, and common scab by roughly 18 to 38 percent compared to continuous potato. Adding a winter rye cover crop after the rotation crop further reduced black scurf and common scab. The combined effect of a canola rotation plus winter rye cover brought disease severity down by 35 to 41 percent for black scurf and 20 to 33 percent for common scab relative to continuous potato with no cover crop.

¹³

On the insect side, the Colorado potato beetle is the most damaging pest in many regions. It has a remarkable ability to develop resistance to individual insecticides, which is why integrated pest management combining biological controls, crop rotation, and alternating chemical classes is preferred. The logic is straightforward: evolving resistance to a single chemical requires just one or a few genetic changes, but overcoming multiple control strategies simultaneously requires coordinated changes that are far less likely to arise.

¹⁴

Vine Kill and Preparing for Harvest

The decision about when and how to kill the potato vine is one of the most consequential timing calls a grower makes. While the vine is alive, tubers keep growing and their skin remains thin and fragile. Vine kill, usually achieved with a desiccant herbicide or by mechanical flailing, stops tuber growth and triggers the skin to “set,” or toughen into a protective barrier. Physically immature tubers with poor skin set are prone to skinning and mechanical damage during harvest, which leaves them vulnerable to dehydration and infection by rot-causing pathogens in storage.

¹⁵

The general rule is to desiccate the vines at least two weeks before the intended harvest date. Research on early-maturing cultivars found that the greatest improvements in postharvest quality came from early desiccation, giving tubers enough time to develop a firm skin before the harvester arrives.

¹⁶

Vine kill also affects the sugar profile of tubers headed for processing. Desiccant application and harvest timing both have persistent effects on tuber physiology that carry through into storage.

¹⁷

Harvesting Without Destroying the Crop

Modern potato harvesting is fully mechanized in most commercial operations. A harvester runs a blade beneath the row, lifts the soil and tubers onto a series of chains and screens that separate tubers from dirt and rocks, and deposits the potatoes into a trailing bin or truck. The process is fast but violent by the standards of a fragile, starch-filled tuber, and managing damage is a constant concern.

Two variables drive most harvest damage: the forward speed of the harvester and soil moisture. Harvesting in dry soil leads to greater impact intensity and more damage to the tubers, because dry soil clods act like hard projectiles on the chain and the soil does not cushion impacts. In wet conditions, the increased flow of moist soil through the machine actually cushions the tubers and reduces damage. Pre-harvest irrigation of dry soils is a practical tool growers use specifically to protect tuber quality.

¹⁸

Optimizing machine settings also matters. Field trials in Saudi Arabia identified specific combinations of forward speed, digging depth, and chain speed that achieved a tuber recovery rate above 97 percent with a damaged tuber rate of only 0.04 percent.

¹⁹

Those numbers represent best-case conditions, but they show what careful calibration can achieve.

Curing and Storage

Once out of the ground, potatoes need to be cured before going into long-term storage. Curing is a brief period, usually around two weeks, of warm, humid conditions that allow cuts and bruises from harvest to heal. The tuber forms a protective layer called wound periderm over damaged areas and deposits suberin, a waxy substance that seals the wound. Research found the optimal curing conditions to be about 25°C (77°F) with 98 percent relative humidity. Temperature was the single most important factor for forming the protective periderm, while humidity had a larger effect on minimizing water loss and resisting infection by common storage pathogens.

²⁰

After curing, storage temperatures are gradually lowered. The target depends on what the potatoes are destined for. Table stock and seed potatoes are typically held at 38–42°F (3–6°C), while processing potatoes for chips or fries are kept warmer, often around 45–50°F (7–10°C), for reasons that have to do with sugar chemistry. Sprout suppression during storage is a separate challenge, traditionally managed with chemicals and more recently with a range of natural and synthetic molecules that interfere with bud growth.

²¹

Why Cold Storage Creates a Processing Problem

Here is a wrinkle that surprises many people: cold storage keeps potatoes from sprouting but also triggers an unwanted chemical change called cold-induced sweetening. When tubers are stored below about 8–10°C (46–50°F), starch begins to break down into reducing sugars like glucose and fructose. That sugar accumulation is a major problem for the processing industry because those sugars react with amino acids during frying to produce dark, bitter-tasting products and elevated levels of acrylamide, a compound considered a potential carcinogen.

²²

This is why processing potatoes are stored at warmer temperatures than table stock, which trades off slightly more sprouting risk for acceptable fry color. Researchers have also tackled the problem genetically. Knocking out the gene responsible for the enzyme that converts sucrose into glucose and fructose in the tuber’s storage vacuole produced tubers with undetectable levels of reducing sugars, lighter-colored chips, and lower acrylamide after frying. On the non-genetic front, treatments with salicylic acid have been shown to suppress the genes driving starch-to-sugar conversion, offering a potential post-harvest intervention.

²³

Heat Stress and the Climate Challenge

Potatoes are a cool-season crop by nature, and rising temperatures present real problems. Heat stress during the growing season reduces marketable yield and quality in ways that go beyond simply smaller tubers. High temperatures cause external defects like heat sprouts (secondary growth), chained tubers, and knobby misshapen tubers, as well as internal problems like vascular discoloration, hollow heart, and internal heat necrosis.

²⁴

The internal defects are especially damaging because they are invisible from the outside. Internal heat necrosis, characterized by brown dead tissue inside otherwise normal-looking tubers, is worsened by high day and night temperatures combined with low rainfall early in the growing season.

²⁵

Breeding for heat tolerance is an active area of research. The wild relatives of cultivated potato, numbering over 100 tuber-bearing species, represent a deep reservoir of genetic diversity that breeders can draw on. Genomic studies have identified thousands of genes under selection during potato domestication, including those controlling carbohydrate metabolism, toxin biosynthesis, and circadian rhythm. Only a small fraction of those selected genes overlap between potatoes adapted to highland Andean conditions and those adapted to longer days and warmer lowland climates, suggesting that distinct genetic toolkits drove adaptation in different environments.

¹⁰

Sorting and Grading After Harvest

After potatoes leave the field and come out of curing, they go through grading and sorting before reaching consumers or processing facilities. In modern packing operations, computer vision systems scan individual tubers as they move along a conveyor, classifying them by shape and size. One such system achieved correct classification rates above 96 percent for distinguishing regular from irregular potatoes, and 100 percent accuracy for sorting well-shaped tubers by size.

²⁶

Misshapen tubers, while perfectly edible, are typically diverted to processing (where shape does not matter after peeling and cutting) rather than the fresh market.

The Future With Hybrid True Potato Seed

The biggest potential disruption to how potatoes are produced is the development of hybrid true potato seeds. Instead of planting bulky seed tubers that must be stored cold and transported at great expense, growers could plant actual botanical seeds, like you would with tomatoes or peppers. This would slash seed logistics costs, reduce the risk of tuber-borne disease transmission, and open potato production to regions where cold-chain seed storage is impractical.

The technology is still maturing. Field trials under Dutch conditions have shown that direct sowing of hybrid true potato seeds is feasible but faces challenges with plantlet establishment. Success rates need to improve through better seed quality, agronomic practices, and genetic improvements that boost early vigor and overall yield.

²⁷

If the approach succeeds at scale, it would fundamentally change the first step of the production chain described above, replacing the tissue-culture-to-seed-tuber pipeline with something closer to how most other crops are grown. Several companies are actively working toward this goal, and the pace of breeding progress has accelerated with genomic tools that allow targeted crossing of inbred diploid lines rather than relying on the complex genetics of the traditional tetraploid potato.