Tomatoes aren’t known for being hardy plants. They can’t handle any frost, so they need to be protected during cold, icy winters if you want them to survive. But, it’s not just icy weather that affects or kills tomatoes – they can be damaged by cold temperatures when there isn’t any frost.
If your tomato plants are starting to grow, you want to ensure you protect them so that they can thrive and produce delicious tomatoes during the harvest, especially since some tomato plant varieties can produce upwards of 30 tomatoes per plant.
If they’re exposed to cold temperatures, they won’t produce a high yield or their tomatoes won’t be of a good quality. But, what temperature is suitable for tomatoes, and what temperatures are important to avoid?
Read on to find out everything you need to know about the temperatures tomatoes can handle and when to protect them so the temperature in your region does not affect their growth in a negative way.
How Does Temperature Affect Tomato Crops?
Cold temperatures can affect tomato crops in many devastating ways. When the temperature gets between 32 and 41°F (0°-5°C), tomatoes will be affected by experiencing:
- Stunted growth
- Drooping or wilting
- Surface pitting on fruit
- Foliage necrosis
- Increased fragility and risk of disease
When the soil temperatures get too cold, this can also affect tomato growth by negatively affecting plant root growth. If temperatures are very low, such as around 50 °F (10°C), tomato plants will struggle to self-pollinate, resulting in difficulty with fruit production.
In order to produce a healthy tomato harvest, it’s essential to ensure that the plants aren’t exposed to temperature fluctuations, either. Stable temperatures are required in order to encourage healthy plant growth. Otherwise, you risk harvesting fewer tomatoes on the plants and poor-quality fruit.
When you harvest your tomatoes, pick them when they change from green to yellow or orange, depending on the variety that you’re growing. Bear in mind that the ideal temperature range for tomatoes to ripen is between 68° and 77°F (20-25°C). If the temperature is too cool, this will slow down the tomato ripening rate.
What’s the Best Temperature for Tomato Crops?
Tomato crops need a healthy daytime temperature range of between 70 and 85°F (21.2-29.4°C). Anything higher or lower will disrupt the plants’ pollination so that flowers will drop, and this will interfere with the production of the plant’s fruit. At night, tomato plants need to be grown within a range of 59 and 68°F (15-20°C).
If you’re growing tomatoes from seeds, these seeds will need temperatures of between 58 and 60°F (14.4-15.5°C) when kept indoors, as this will encourage germination. As the crops grow, they will need warmer temperatures – 70 and 85°F (21.2-29.4°C) during the day and between 59 and 68°F (15-20°C) during the night.
Although these are the temperature guidelines to follow when growing tomatoes, the kind of warmth that tomatoes need is dependent on giving them the correct type of sunlight.
Tomato plants aren’t just sensitive to very cold temperatures, but too much heat and sunlight can also spoil them. When tomatoes are exposed to heat stress, this can cause them to engage less in pollination, which affects their harvest.
When growing tomatoes, make sure that you provide them with full-sun conditions as this encourages them to thrive. Give them between six and eight hours of sunlight every day. During the summer, try to protect your tomatoes from the harsh afternoon sun. You can do this with row covers to provide them with a bit of shade.
Make sure you increase the frequency of watering your tomatoes during the hottest and driest times of the year to prevent them from drying out.
What’s the Lowest Temperature Tomato Crops Can Tolerate?
The temperature that tomato crops can tolerate is 33°F (0.5°C). If the temperature is lower than that, which is when frost forms, the plants will experience stunted growth and even death.
But, you shouldn’t let temperatures reach 33°F (0.5°C) even though tomatoes can survive at this temperature. That’s because temperatures that are even lower than 50°F (10°C) can cause growth problems and pitted tomatoes that spoil your harvest.
Just because your tomato plants can survive at a temperature of 33°F (0.5°C), their growth will be stalled, and it will take a very long time for the tomato plants to recover to the point of being able to produce fruit.
Your tomatoes can also experience negative side effects from being exposed to temperatures lower than 60°F (15.5°C), such as cat-facing. This refers to damage caused to tomatoes in the form of cracks and scars that appear on the fruit, and it strikes when night-time temperatures dip lower than 60°F (15.5°C).
If your temperature is consistently lower than 70°F (21.1°C), this can also affect your tomatoes by encouraging the growth of grey mold. This type of fungal infection can adversely affect your tomato plants and their fruit.
To prevent it, it’s vital to ensure that the tomato plants are exposed to temperatures higher than 70°F (21.1°C) and that they have enough air circulation between them, especially on humid or wet days when mold growth is encouraged.
Growing healthy, juicy tomatoes require warm temperatures. You must protect your tomatoes from cold temperatures as these can reduce how much fruit tomato plants produce and how well they can grow.
Make sure you keep your tomato plants at a comfortable temperature, ideally within the range of 70 and 85°F (21.2-29.4°C) during the day and between 59 and 68°F (15-20°C) during the night.