Tomato cultivation: ideal growing conditions

Understanding the real needs of the plant is the first step towards productive and sustainable cultivation. A technical guide for those working in the field.

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Why tomato cultivation is strategic worldwide

The tomato (Solanum lycopersicum L.) is now one of the most widespread and strategic horticultural crops in the world.

At the heart of extensive supply chains — from fresh produce to sauces, purées, concentrates and juices — it is the second most consumed vegetable globally after potatoes.

189

million tonnes

Global production, with China and India among the leading producers.

6

million tonnes

Italian production, making Italy the leading producer in Europe.

20-50

t/ha

yield under ideal agronomic conditions.

90-120

days

from transplanting to harvest.

Tomato cultivation requires precise management of temperature, irrigation, nutrition and sunlight.
In this technical guide, we analyse the ideal agronomic conditions — climatic, soil-related and nutritional — needed to obtain high-quality production both in open fields and protected environments.

Tomato climate requirements

The importance of temperature

The tomato is a light-loving and heat-loving species: it needs abundant light and stable temperatures to move correctly through all phenological stages — from germination to flowering, fruiting and ripening.

icona parametri microclimatici

Optimal growing temperature

18–26°C (particularly important during the germination stage)

icona piantina di pomodoro

Temperature inhibiting

carotenoid synthesis: above 35–36°C

temperature

Tolerated temperature range

10–35 °C

Watch out for summer!

Heatwaves above 35°C, which are becoming increasingly frequent, can block lycopene synthesis and compromise the quality of the final product. Colour is, in fact, a key parameter for industrial tomato production. Monitoring temperatures during the ripening stages is essential in order to act promptly with emergency irrigation or shading.

OP APOD’s agrometeorological stations and DSS systems make it possible to detect heatwaves and water stress immediately, optimising every field intervention.

sun

Light and CO₂

Tomatoes require at least 6–8 hours of direct sunlight per day.
Light, together with CO₂ concentration, regulates photosynthesis and therefore biomass production.

water soil

Humidity and soil

The optimal relative humidity ranges from 65% to 75%. Excessively high values encourage fungal leaf diseases, while excessively low values cause water stress and fruit set problems.

Tomatoes prefer soft, well-drained soil to avoid waterlogging, which can lead to root rot and soil-borne pathogens. The ideal soil pH is between 6.0 and 7.0.

wind

Wind and pollinators

The tomato is a self-pollinating species: in open-field cultivation, it is naturally pollinated by the wind, while in greenhouses it requires specific support.

For this reason, it is important to introduce pollinators such as bumblebees and bees. By visiting the flowers, these insects produce a vibration known as buzz pollination, which encourages fruit set and helps obtain more uniform fruits.

spqni

Protecting pollinators is therefore not only an ethical choice, but also a strategic agronomic tool, as explained in the in-depth article on their role and APOD’s SQNPI certification.

Tomato nutritional requirements

Tomato nutritional requirements vary according to the nutrients already present in the soil, the variety grown and the production system adopted.

In general, the nutritional requirements for open-field cultivation with a yield of 50 t/ha are:

Nitrogen (N)

135–160 kg

Phosphorus (P₂O₅)

50–55 kg

Potassium (K₂O)

230–250 kg

Magnesium (MgO)

50–60 kg

The next step: proper sowing

The climate and nutritional requirements of tomatoes described in this guide are already relevant from the very first stages of the crop cycle.

It is in the nursery, in fact, that the foundations of productivity are built: a healthy, uniform and well-nourished seedling will be ready at transplanting to make the most of field conditions.

Several factors influence the quality of the initial stage:

  • the choice of certified seed, guaranteeing varietal purity and the absence of pathogens;
  • temperature and humidity control during germination;
  • light management and the prevention of legginess;
  • correct transplanting times, calibrated according to climate and growing area.

Frequently asked questions about tomato cultivation

What is the ideal temperature for growing tomatoes?

Tomatoes grow best at temperatures between 18 and 26°C. They can tolerate a range of 10 to 35°C, but above 35–36°C lycopene synthesis stops, affecting the colour and quality of the fruit, especially in varieties intended for industrial processing.

From transplanting to harvest, the crop cycle lasts on average 90–120 days, depending on the variety, climate and cultivation technique. Early varieties can complete the cycle in 85–90 days, while late industrial varieties can exceed 130 days.

Tomatoes prefer well-drained soils with a pH between 6.0 and 7.0 and a good supply of organic matter. Values outside this range reduce the availability of essential nutrients, particularly phosphorus and micronutrients.

The average water requirement is 400–600 mm per crop cycle, distributed evenly. Water stress during flowering and fruit enlargement can cause flower and fruit drop, blossom end rot and a reduction in fruit size.

Under optimal agronomic conditions, yields range from 20 to 50 t/ha for open-field processing tomatoes, with peaks of 80–100 t/ha in protected cultivation or well-managed intensive systems.

Transplanting takes place when minimum night-time temperatures remain consistently above 10–12°C. In northern Italy, this is typically from mid-April to late May, while in southern Italy it can begin as early as late March.

Tomatoes respond best to localised drip irrigation, which keeps the soil evenly moist, reduces the risk of foliar diseases and optimises water use.

In open-field cultivation, overhead irrigation is avoided during flowering, as wetting the flowers can compromise fruit set.

Irrigation frequency should be adjusted according to the phenological stage: more limited before flowering and more regular during fruit enlargement.

tomatoes

Sei un produttore o un operatore della filiera del pomodoro?

APOD supports its members in selecting plant material and planning the initial stages of cultivation, providing certified seedlings and dedicated agronomic support for tomatoes, asparagus and other strategic crops within the supply chain.

Read the full guide to tomato sowing:

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