When Is It Safe to Put Tomato Plants Outside?

Tomatoes are a popular vegetable to grow in gardens and containers. However, before putting your tomato plants outside, it is important to consider several factors to ensure their success.

Frost Dates

The biggest concern when it comes to planting tomatoes outside is the threat of frost. Frost can damage or even kill tomato plants. In general, it is safe to plant tomatoes outside after the last expected frost date in your area. However, it is important to note that these dates can vary from year to year.

To determine the last expected frost date in your area, you can consult a gardening guide or your local extension office. You can also check online resources that provide frost date calculators based on your zip code.

It is also important to note that tomato plants are sensitive to frost, even if they are not completely frozen. If temperatures drop below 45-50°F (7-10°C), tomato plants can suffer from cold damage, which can stunt their growth and reduce their yield.

Soil Temperature

In addition to frost, soil temperature is another important factor to keep in mind when planting tomatoes outside. If the soil is too cold, it can slow down the growth of your plants or even cause them to die.

Tomatoes prefer soil temperatures of at least 60-65°F (15-18°C) before transplanting. To check the soil temperature, you can use a soil thermometer, which is available at most gardening stores. Alternatively, you can use your hand to feel the soil. If it feels cool or cold to the touch, it is likely too cold for planting tomatoes.

Seedling Age

Finally, the age of your tomato seedlings is also an important consideration. Seedlings that are too young or too old can be more susceptible to damage from frost, wind, and other environmental factors.

In general, it is safe to plant tomato seedlings outside when they are 6-8 weeks old and have at least 4-6 leaves. At this point, they are strong enough to handle transplanting and have a better chance of surviving in the outdoor environment.

Conclusion

Planting tomatoes outside can be a fun and rewarding experience. However, it is important to consider several factors before doing so to ensure the success of your plants. By paying attention to the last expected frost date, soil temperature, and seedling age, you can increase your chances of growing healthy and productive tomato plants.