How Long for Tomatoes to Grow True Leaves?

Home growers enjoy vine ripened, flavorful tomatoes.

Store-bought tomatoes can't compare with the flavor of homegrown vine-ripened fruits. Starting tomato seedlings to get a jump on the harvest gives you a high return for a little effort.

Early Development Stages

During germination the stem and seed leaves emerge, as on this bean .

Experts at the University of Arizona recognize three stages of development for tomato seedlings -- germination, post-emergence and transplant.

Germination and Post Emergence

Tomato seeds germinate in 5 to 7 days.

Most tomato varieties germinate in five to seven days under proper conditions. Post-emergence occurs in five to 12 days if tomatoes are grown hydroponically, in 14 to 21 days if soil-grown.

Seed Leaves

Seed leaves, like the ones on these sprouts, are directly opposed.

Seed leaves (cotyledons) are the first leaves formed on a tomato and appear during the post-emergence phase. They are two single, smooth-edged, long and narrow leaves directly opposing each other. True leaves will sprout above the seed leaves.

True Leaves

Tomato true leaves are lobed.

True leaves are the second set of leaves developed. They are compound when fully developed, meaning they have more than one leaflet attached to the leaf stem (rachis). They differ from seed leaves in being lobed (notched edges).

Timing

The average tomato seedling is 2 inches high when true leaves appear.

The first true leaves can appear on hydroponically grown seedlings at five to 12 days after germination. True leaves usually appear on soil-grown seedlings at two to three weeks of age (14 to 21 days). At this point, the average tomato seedling is about 2 inches high.

References

• University of California Davis: Lycopersicon Esculentum, Tomato, An Anatomy Atlas
• University of California Davis: Lycopersicon Esculentum, Tomato, An Anatomy Atlas
• University of Arizona College of Agriculture and Life Sciences: Growing Tomatoes Hydroponically
• Canadian Space Agency, Agriculture and AGri-Food Canada, Tomatosphere.org: Seeds and Germination
• Texas A&M AgriLife Extension: How to Grow the Tomato and 115 Ways to Preapre it for the Table

Resources

• Canadian Organic Growers: Tomato Seedlings Without a Greenhouse
• North Carolina State University Extension: Starting Plants from Seeds, Transplanting