According to the 1997 Sunset National Garden Book, tomatoes are the most popular and prolific of fruit or vegetable plants. Tomato plants go through several distinct growth stages before developing enough to produce fruit. These plants are fast growers that thrive when temperatures are between 50 degrees Fahrenheit overnight and 85 degrees during the day. Like all plants, tomatoes develop into seedlings a few weeks after seeds are sown. Tomatoes thrive in full sun with regular water and should be staked or caged.
After seeds have sprouted, tomato plants will take about a month to begin to develop a strong stem and branch structure. After the initial two oblong leaves sprout on a seedling, the distinctive lobed leaves will begin to grow from the center of the seedling and the stem will become thicker.
As the tomato grows and becomes stronger, it will begin to produce flowers, which go through three stages. Flower buds, which are small and fuzzy, will appear at the ends of small branchlets, called trusses. These buds will become elongated and the yellow flower petals will become visible between the sepals before the bloom opens.
The flowers will open into small, star-shaped yellow blooms with a long, anther cone in the center. The flowers will be unblemished until pollinated by a bee, at which point they will appear bruised. Once the bloom is pollinated, it will begin to die and drop as a fruit begins to grow.
Set fruit in its early stages is small, green and pea-sized. As the fruit matures, it may become round, grape-shaped or elongated, depending on variety. Immature fruit is green and firm. When the fruit stops growing, the skin begins to change color, and may be red, pink, yellow, orange or white, depending on the variety. The longer the fruit is left on the vine to ripen, the more flavorful it will be.
End of Season
After tomatoes have been harvested, tomato plants will begin to die back. Leaves and stems will yellow, turn brown and dry out. Plants should be cut back or removed. Tomatoes are perennials, and in more mild climates they should survive the winter.