Can You Plant Tomato Plants in Summer?

Northern Climates

• In northern regions where summers are cool and short, tomatoes planted in midsummer may not have time to mature before the weather cools in fall. For that reason, tomato seedlings are typically transplanted to the garden in the spring or early summer as soon as nighttime temperatures remain above 55 degrees Fahrenheit. Those planted later in the year may not produce fruit, or the fruit may not have time to ripen on the vine and produce its fullest flavor.

Southern Climates

• In southern regions, where summers are long and hot, tomatoes can be planted in summer but may need protection from the sun, especially during midday when the rays are strongest. Planting them in a sheltered location where they receive morning light and are shaded during the hottest part of the day offers some protection. Tomato plants may still require frequent watering to keep them hydrated during hot, dry spells. Planting in containers that can be moved allows you to temporarily move tomatoes to a sheltered area should a heat wave strike.

Potential Climatic Issues

• Tomato plants may suffer from poor pollination in areas where summertime temperatures soar above 90 degrees Fahrenheit during the day and remain above 70 degrees Fahrenheit at night. This may occur for two reasons: blossoms may drop in high temperatures, and pollen may be killed. Carl Cantaluppi from the Granville County Center of North Carolina State University Cooperative Extension explains that a pair of days with just three hours of temperatures above 104 F may cause tomatoes to fail to set fruit. Tomatoes may also suffer from sun scald, develop yellow "shoulders" on the skin near the fruit's stem or form hard white areas inside the fruit when grown in direct sun at high temperatures.

Days to Maturity

• Tomato varieties range in days to maturity from as few as 50 to 80 days or more, depending on the cultivar. Days to maturity refers to the number of days for your tomatoes to ripen on the vine from the date of transplanting seedlings to the garden. Choosing a tomato variety with fewer days to maturity than the number of frost-free days in your area is vital to success with growing tomatoes, particularly when planting tomatoes late. Count backward from the expected fall frost date to determine when your tomatoes planted in summer can be reasonably expected to mature before the fall frost.