The time it takes to grow a tomato from planting to harvest can vary significantly. The total growing period is an accumulation of time spent in different developmental phases, influenced by factors like the initial method of starting the plant, the specific variety chosen, and environmental conditions. Understanding the timeline for each stage allows a grower to predict the first harvest with more accuracy.
Seed Starting vs. Transplants
The overall time required to grow a tomato begins with the decision of whether to start from a dry seed or a pre-grown seedling, known as a transplant. Starting with a seed adds a substantial period to the timeline before the plant is even placed in the garden soil. Seeds must first germinate, which typically occurs within five to ten days when the soil temperature is maintained near the optimal 70°F (21°C) to 85°F (29°C) range.
After germination, young plants must be grown indoors until they reach a viable transplant size, a phase that usually takes six to eight weeks. Buying a transplant effectively bypasses this initial period, immediately advancing the timeline by up to two months. The goal of this indoor stage is to produce a robust plant with a developed root system ready for final planting after the risk of frost has passed.
How Variety Type Affects Timing
Once established, the specific variety chosen is the most important factor determining the harvest date. This timing is quantified by the “Days to Maturity” (DTM) listed on seed packets, representing the approximate number of days from transplanting until the first fruit is ready. These timelines are primarily determined by the plant’s genetics.
Varieties are categorized based on maturity rate. Early-season varieties produce ripe fruit in 50 to 70 days after transplanting. Mid-season types require 70 to 80 days, while late-season varieties, often including larger beefsteak tomatoes, can take 80 to over 100 days. Another genetic factor is growth habit: determinate varieties produce a concentrated harvest, while indeterminate types fruit over an extended season.
Environmental Influences on Growth Speed
The Days to Maturity figure is an estimate modified by the surrounding environment. Temperature is the most influential factor, as tomatoes thrive when daytime temperatures are between 70°F (21°C) and 82°F (27°C). Growth and fruit development slow down considerably when temperatures consistently fall below 60°F (16°C).
Excessive heat can also delay or prevent fruiting. Nighttime temperatures above 75°F or daytime temperatures exceeding 90°F can cause failure in flower development and pollen viability, leading to blossom drop and halting fruit set completely. Furthermore, the fruit’s red pigment (lycopene) will not properly form above 86°F, slowing or stalling the ripening process.
Adequate sunlight and consistent moisture also play a large role in maintaining the expected growth schedule. Tomatoes require full sun, and a lack of light reduces photosynthesis, slowing progress toward fruiting. Irregular watering creates stress that can delay the onset of fruit production.