Growth Cycle of a Tomato

Germination

• Tomato seeds typically germinate and sprout, within one to two weeks of planting, depending on the variety. A combination of nutrient-dense soil, such as a sterile potting mix, moisture, light and temperatures between 65 to 75 degrees F, create the optimal environment for growth. Under the soil, the seed absorbs moisture and nutrients, causing the outer coating, or cotyledon, to swell, activating the embryo inside. As the embryo develops, the root, also called a radicle, pushes through into the soil. While the radicle pushes down, the developing stem and plant push upward and eventually break through the soil surface in search of light, which is required to begin photosynthesis.

Early Growth and Development

• Once the seedling emerges, the main stem, branches and leaves begin to develop. The root system continues to develop below the soil, forming larger, anchor roots and a network of smaller, hair-like roots, which absorb moisture and nutrients from the soil. At this stage, seedlings planted in the same container are thinned after three to four weeks of growth, to allow the strongest plants room to fully develop. Most tomato plants require some sort of support, in the form of stakes, cages or trellises, to protect the plants from high winds, storms and to keep the branches off the ground when the tomatoes form and grow.

Fruit Development

• Once the plant is fully developed, fruit production begins. Clusters of flowers begin to form along the strongest branches. At this point, pinching off any suckers, which sprout at the point between stronger stems and branches, increases production by directing absorbed nutrients to the fruit instead of any additional foliage. Pollination occurs, when the flowers are fully developed, through the aid of wind and garden insects, such as bees. Successfully fertilized flowers begin to grow into tomatoes. Determinate tomato varieties reach their full height during this phase, when all flowers begin to form fruit. Indeterminate varieties continue to grow and produce fruit throughout the season.

Maturity

• Tomatoes reach mature size after nearly a month. At this point, the fruits begin to ripen and change color. Unlike mass-produced retail tomato crops, which are harvested green and wmanually ripened, home-grown tomatoes, allowed to ripen on the plant, absorb the maximum amount of nutrients and develop their true texture, color and flavor. While determinate varieties mature within the same one- to two-week period and typically produce no more fruit, indeterminates never reach maturity, instead producing constantly until the first frost of the season. Depending on the variety grown, the time from planting to harvest takes from 45 to 90 days.