Tomatoes undergo four main stages of growth during their life. They start out as a seed, following germination they will become a sprout or seedling. As the plant matures it rapidly grow foliage and flower. This is followed by fruiting stage. Finally the plant will die back as the days get colder and finally die usually during a frost.
The first stage is of course the seed sprouting. If you are growing tomatoes from seed, you can expect your seed to germinate and sprout within about eight days. In order for tomatoes to sprout they need damp to moist soil. They will also need temperatures to stay between 75-85 degrees Fahrenheit. The sprouts will unfurl seed leaves – these are not true leaves. During this stage the tomato sprout will begin growing its root system, using the cotyledons or seed leaves to begin the process of photosynthesis. You can speed up this stage somewhat by giving your sprouts about twelve to fifteen hours of light each day.
After a few weeks the tomato plant will enter its second stage of growth. Here the plant will begin to make its first set of true leaves. During this stage most of the tomato plant’s energy is directed toward forming strong roots and leaves. The stem will get stronger to support the increasing weight of the leaves. Since tomatoes are in the Nightshade, or Solanacea family, they need at least six hours of full sun every day.
In the third stage of growth the tomato plant will begin to set its first set of flowers. Determinate tomato plants are ones where the plant bears all of its fruit at once. Following this third stage of growth, these plants will generally stop growing new leaves. The plant will also not get any taller. Indeterminate tomato varieties will continue to grow taller, produce new leaves, and set additional flowers…often well after this stage of growth.
The fourth stage of tomato growth begins when the flower petals die back and the tomato fruit begins to swell. Tomato fruit start out a green color and will retain this color until the fruit reaches full size. When the tomato is full sized the fruit will begin to ripen. The first sign of ripening occurs at the bottom of the fruit or the blossom end. Indeterminate varieties will stay in this stage of growth for longer than determinate ones. Semi-determinate tomato varieties will fall somewhere in between.)
In the final stage of growth, the tomato will begin to die back. You can still harvest ripe tomatoes and even the green ones in this final stage. Store the green tomatoes at room temperature for two weeks. If you live in an area that does not experience frost, a tomato plant can live for two years. However, it will not set fruit if it gets too hot or too cold. When the temperature becomes conducive, they will begin fruiting again.
Tomato plants are known as an annual plant. Once the season is over they will not go dormant for the winter, and then grow again the following spring and summer, like a perennial or biennial plant.
Over the years tomato pests and diseases become more common place. Be sure to plant tomatoes in different places every year.