What Temperature is Too Cold for Tomato Plants?

Tomatoes are one of the most popular garden vegetables, but they are actually a fruit. They’re relatively easy to grow, but they are also sensitive to temperature. Tomato plants can tolerate a wide range of temperatures, but there is definitely a temperature below which they will start to struggle. In this article, we’ll explore what temperature is too cold for tomato plants, and what you can do to protect them.

Tomatoes 101

Before we talk about cold temperatures, let’s briefly review what tomato plants need to grow and thrive. Tomatoes need full sun, fertile soil, and consistent water throughout the growing season. They also need plenty of nutrients, so it’s important to fertilize regularly. If you provide these basic needs, you’ll be well on your way to a successful tomato harvest.

Cold Tolerance

Tomato plants can tolerate a range of temperatures, but they prefer a daytime temperature of about 75°F (24°C) and a nighttime temperature of about 60°F (16°C). Tomatoes can tolerate temperatures up to 90°F (32°C), but they start to struggle when temperatures exceed 95°F (35°C).

On the other end of the spectrum, tomatoes can also tolerate some cold temperatures. If the temperature drops below 55°F (13°C), tomato plants may experience slow growth and reduced fruit set. If the temperature drops below 50°F (10°C), the plant may start to show signs of stress, including wilting and leaf dieback. If the temperature drops below 40°F (4°C), the plant will stop growing altogether, and may eventually die.

Protecting Your Tomato Plants

So what can you do to protect your tomato plants from cold temperatures? Here are a few ideas:

Cover them up. When temperatures are expected to drop below 50°F (10°C), cover your tomato plants with row covers, blankets, or plastic sheeting. This will help to trap the warmth from the soil and protect the plants from windchill.

Water them. Water the soil around the tomato plants thoroughly before a cold snap. Wet soil holds heat better than dry soil, which will help to keep the plant roots warm.

Use mulch. Mulching around tomato plants can help to insulate the soil and protect the plant roots from temperature fluctuations.

Plant strategically. If you live in a particularly cold climate, choose tomato varieties that are specifically bred to be cold-tolerant. You can also plant your tomatoes in a sheltered location, such as against a south-facing wall or near a heat-absorbing structure.

In Conclusion

Tomatoes are an incredibly versatile and delicious fruit, but they are also sensitive to temperature. When temperatures drop below 55°F (13°C), tomato plants may struggle to grow and produce fruit. When temperatures drop below 40°F (4°C), the plant may stop growing altogether and eventually die. To protect your tomato plants from cold temperatures, you can use a variety of strategies, including covering them up, watering them, using mulch, and planting strategically. By taking these steps, you can help ensure a successful tomato harvest, no matter what climate you live in.