The Life Cycle of a Tomato Plant


Tomatoes come in a wide range of types, sizes and colors. They are used as a relish, a garnish, a vegetable and as an ingredient in many recipes. Tomatoes are easy to grow and adaptable to a variety of soils. In spite of all the differences, all tomatoes begin and end the same way. The life cycle of one type of tomato is the same as another.


Tomatoes begin as the seeds they carry within. The seeds must go through a period of dormancy or stratification. This is when the seeds must be exposed to the cold temperatures of winter before they become viable. Once this process is completed, they can be sown indoors six weeks before the last projected frost date or outdoors once the danger of frost has passed.


Temperatures need to be between 75 and 85 degrees before seeds will germinate and sprout. With the correct temperatures and moisture, seeds will germinate in five to 10 days. Once they emerge, they need consistent temperatures between 65 and 75 degrees to thrive. By the time they are 2 to 3 inches tall, they will have several sets of leaves. If seedlings are started indoors, they should be hardened off once night time temperatures maintain 50 degrees. Hardening off is the setting outside of indoor plants each day, for gradually increasing periods of time to help them adjust to moving outdoors. Seedlings can be thinned and indoor plants moved outdoors when they are about four to six weeks old.


Tomato plants become weighed down by the weight of their fruits. Tomato cages or stakes are generally used to hold them up as the fruits develop. The plants are set in rows about 3 feet apart. After several weeks, depending upon the variety, flowers will bloom. The flowers are pollinated by insects and the blooms drop off. Tomatoes will develop in their place.


The young tomatoes need quite a bit of water, up to 2 to 3 inches per week. The length of time it takes for the tomato to fully develop depends on the variety of tomato. Some are ready within 45 days of planting while others can take as long as 100 days. Also, some varieties fall into the "determinate" category, meaning they set fruit once and then stop growing. Other varieties are "indeterminate" and will continue growing and setting new fruit throughout the growing season. Tomatoes are ripe when their color has taken on the appropriate shade of red, yellow or orange and when the flesh gives way slightly to pressure from your finger.

Full Cycle

The tomato plant develops its seeds inside the tomato. In nature, the tomatoes would fall to the ground, decay and the seeds would spend the winter in the soil. Animals would eat some of the tomatoes, passing the seeds through their waste product and spreading them to other areas where they would undergo the natural stratification process. In order to save seeds for next year's crop, ripened tomatoes can be cut open and the seeds removed. These seeds should be allowed to air dry and then be stored in a cool, dry place until the following spring when they are ready to be planted.

Keywords: tomato plants, life cycle, seedlings

About this Author

Theresa Leschmann has been a freelance writer for five years. She has written for local newspapers as well as websites such as Associated Content, Helium, Bukisa and Demand Studios. She also writes movies reviews for and writes a blog, Movie Muse. Leschmann brings her love of home and garden, traveling and movies to her writing.