How hot is too hot to plant tomatoes?

Answered by Stephen Mosley

When it comes to planting tomatoes, the optimal temperature range is between 75 to 95 degrees Fahrenheit. However, it is important to note that tomatoes have their preferences and can be quite sensitive to extreme heat. If the temperatures rise too high during the day, typically over 85 degrees, or remain hot overnight, exceeding 70 degrees, it can have detrimental effects on tomato plants.

One of the main issues with excessively hot temperatures is that it can cause tomato plants to drop their blossoms. Blossom drop occurs when the flowers on the plant fail to develop into fruits, ultimately leading to a decrease in yield. This can be quite frustrating for gardeners and farmers who are eagerly awaiting a bountiful harvest.

Tomatoes are considered warm-season plants and thrive in temperatures that are warm but not scorching hot. When temperatures climb too high, it can disrupt the pollination process. Tomato plants rely on bees and other pollinators to transfer pollen from the male flowers to the female flowers. However, when it’s too hot, the pollen can become less viable, resulting in poor pollination and subsequent blossom drop.

Additionally, high temperatures can also affect the overall health and vigor of tomato plants. Extreme heat can cause stress and lead to wilting, dehydration, and even sunscald. The leaves may start to curl or become crispy, and the plants may struggle to take up water and nutrients from the soil efficiently. In severe cases, prolonged exposure to excessive heat can even lead to the death of tomato plants.

Personal experience has taught me the importance of paying attention to temperature when planting tomatoes. On one occasion, I eagerly planted my tomato seedlings in early spring when the days were warm but the nights were still quite chilly. Despite initially showing signs of growth, the plants started to droop and eventually died off. It was clear that the fluctuation in temperatures, with cold nights and warm days, had taken a toll on the young tomato plants.

To avoid such disappointments, it is crucial to wait until the threat of extreme heat has passed before planting tomatoes. It’s generally recommended to plant tomatoes when the average daily temperature consistently stays within the ideal range of 75 to 95 degrees Fahrenheit. This often occurs during the late spring or early summer in most regions.

If you’re eager to start planting tomatoes earlier in the season, you can take measures to protect the plants from excessive heat. Providing shade during the hottest part of the day or using shade cloths can help mitigate the impact of intense sunlight. Additionally, ensuring adequate soil moisture by watering deeply and consistently can also aid in maintaining optimal plant health.

In conclusion, tomatoes thrive in temperatures between 75 to 95 degrees Fahrenheit. However, temperatures above 85 degrees during the day or over 70 degrees at night can be too hot for tomato plants, leading to blossom drop and other adverse effects. It is essential to monitor the weather conditions and plant tomatoes when the temperatures are within the ideal range to ensure successful growth and a bountiful harvest.