Stages of a Tomato Plant

Tomatoes (Solanum lycopersicum) are tropical perennials that are typically grown as annuals. Not counting the germination of seeds, tomatoes go through roughly four stages of growth: vegetative growth as the seedlings develop, first flowering, first setting of tomatoes and growth of tomatoes until they're ripe and ready for harvest. The duration of these stages vary, depending on the tomato cultivar and the weather.

Immature tomatoes remain green for roughly 40 to 50 days. Once they reach their mature green size, their green fades to light green and then to its cultivar color. This is usually red, but some cultivars are orange, yellow or pink when they're ripe. Mature green tomatoes ripen best at 68 to 77 degrees Fahrenheit. Temperature higher or lower than this range slow the ripening. Tomatoes do not produce carotene and lycopene, necessary for tomatoes to color, when temperatures are above 85 F.

Israeli growers of greenhouse tomatoes found that it took, on average, 15 days for seedlings to develop, another 15 days yield their first flowers, another 10 days before tomatoes set, and another 20 days until harvest. That comes out to about 60 days before first harvest. You may be able to harvest an early-yielding garden tomato that quickly, but most cultivars will take longer.

Tomato plant growth from planting a seedling to harvest depends largely on how long it takes a plant to develop trusses, clusters of flowers that yield tomatoes. When flowers appear on your tomato plant, it’s preparing to grow tomatoes.

If you transplant a nursery tomato seedling, look for plants that are 6 to 8 inches tall with the flowers of first truss starting to open.

Two basic types of tomatoes grow trusses differently: indeterminate and determinate.

Older tomato cultivars, called indeterminate tomatoes, grow trusses of blossoms on side branches, not on their tips. Indeterminate tomatoes can grow close to 7 1/2 feet tall in warm climates and have to be supported by a stake or wire cage. They grow flavorful tomatoes that ripen over a long period. Their tomatoes may be late to mature.

Pinching side shoots on indeterminate tomatoes eliminates excessive trusses and reduces foliage, causing the plants to produce more and larger tomatoes. When an indeterminate tomato has reached the top of its support, remove the tip of the plant, leaving six tomato-producing trusses on the sides of the stem.

Here are some examples of indeterminate tomatoes and their time to harvest:

'Early Cascade' (Solanum lycopersicum ‘Early Cascade'), yields large clusters of 4-ounce tomatoes in 55 days.

'Champion' (Solanum lycopersicum ‘Champion’) yields solid 10-ounce tomatoes in 65 days.

‘Better Boy’ (Solanum lycopersicum ‘Better Boy’), a garden favorite, yields large amounts of 10-ounce tomatoes in 70 days.

‘Beefmaster’ (Solanum lycopersicum ‘Beefmaster’) gives high yields of 16-ounce, deep red tomatoes in 80 days.

Newer tomato cultivars, called determinate tomatoes, grow flower trusses on their tips, so they stop growing taller. They grow as bushes, and some of them are dwarf plants. They do not require pruning of trusses like indeterminate tomatoes, and they yield an abundant quantity of tomatoes that ripen over a short period.

Here are some examples of determinate tomatoes and their time to harvest:

‘Sub Arctic’ (Solanum lycopersicum ‘Sub Arctic’) yields 3- to 4-ounce tomatoes in 45 days. 

‘Mountain Spring’ (Solanum lycopersicum ‘Mountain Spring’) yields smooth, 9-ounce tomatoes in 65 days.

‘Pik Red’ (_Solanum lycopersicum ‘_Pik Red’), a dwarf tomato plant, yields large amounts of 6- to 7-ounce tomatoes in 71 days.

‘Mountain Pride’ (Solanum lycopersicum ‘Mountain Pride’) gives heavy yields of 10-ounce tomatoes in 74 days.

When a determinate plant yields its harvest, it’s finished. No more tomatoes. If you have a long growing season, you can plant another round of determinate tomatoes with a short period of maturation for another harvest.

Sow seeds indoors six to eight weeks before you expect the last frost. It takes seeds seven to 14 days to germinate at 70 F. Whether you grow seedlings yourself or buy them in a nursery, plant them two weeks after the last expected date of frost in your area.

If an early frost halts the ripening of tomatoes, you can ripen mature green tomatoes off the vine, especially if they have a hint of color.