Tomato Growth Stages, From Seed to Harvest
A tomato seed sprouts in 5–10 days in warm soil, then takes roughly 100–120 days from sowing (60–85 days after transplanting) to reach a ripe, harvestable fruit, passing through seedling, vegetative growth, flowering and fruit-ripening stages along the way.
Seed to sprout: germination
How a tomato seed transforms into a visible sprout.
Germination timeline
- 1
Sow the seed
Day 0
Plant the seed about 6 mm (¼ in) deep in moist, warm seed-starting mix. Tomato seeds germinate best between 21–27°C (70–80°F); below 15°C (60°F) they may not sprout at all.
→ Seed in warm, moist soil
Read the steps as text
- Sow the seed. Day 0 Plant the seed about 6 mm (¼ in) deep in moist, warm seed-starting mix. Tomato seeds germinate best between 21–27°C (70–80°F); below 15°C (60°F) they may not sprout at all.
- Seed absorbs water. Day 1–2 The dry seed soaks up moisture through its coat and swells, activating enzymes that turn stored starch into food for the embryo inside.
- Root and shoot break through. Day 5–7 A tiny root (the radicle) emerges first and anchors into the soil, then the stem arches upward, pushing through the surface with its tip bent over to protect the delicate growing point.
- Seed leaves unfold. Day 7–10 The stem straightens and two smooth, oval seed leaves (cotyledons) open to the light and start photosynthesising — the seedling can now feed itself.
Seed to harvest: full life cycle
Every stage of a tomato plant's life, from sowing to picking. It's drawn as a loop, the way a life cycle conventionally is — left to flower and go to seed instead of being harvested, a plant produces the seed for next year's crop.
Full life cycle timeline
- 1
Germination
Day 0–10
The seed sprouts and opens its first seed leaves — see the timeline above for how it happens.
→ Sprout emerges
Read the steps as text
- Germination. Day 0–10 The seed sprouts and opens its first seed leaves — see the timeline above for how it happens.
- First true leaves appear. Day 10–21 Serrated, compound true leaves appear above the rounded cotyledons — the first sign the plant is truly a tomato and not just a generic seedling. Roots keep spreading underground.
- Rapid leaf and stem growth. Week 3–8 The plant grows quickly, putting energy into stems and leaves to build the leaf area it will need to fuel fruiting later. Seedlings are usually transplanted outdoors around this stage, once frost risk has passed.
- First flowers open. Week 6–9 Once the plant has enough leaf area, yellow star-shaped flower clusters open. Tomato flowers are self-pollinating — wind and buzzing bees simply shake pollen loose within the same flower.
- Fruit forms and ripens. Week 9–14 Pollinated flowers swell into small green fruit, which grow for several weeks before ripening — turning from green to yellow, orange, then red as the plant produces the ripening hormone ethylene.
- Ready to pick. ~100–120 days from seed Harvest once the fruit has reached full colour and gives slightly under gentle pressure. Most varieties keep producing new fruit for weeks once they start.
Getting tomato seeds to sprout reliably
Warmth matters more than almost anything else for tomato germination: seeds started at 21–27°C (70–80°F), often with a seedling heat mat, come up in about a week, while seeds left in a cool room can take twice as long or rot before sprouting at all.
Keep the soil moist but not waterlogged, and cover the tray or pot (a clear lid or plastic wrap works) to hold in humidity until the sprouts appear — then uncover it immediately and move seedlings into bright light. Tomato seedlings that don't get enough light right after sprouting grow tall, pale and floppy ("leggy") instead of sturdy.
From seedling to transplant
Before moving seedlings outdoors, harden them off over about a week: set them outside for a couple of hours a day in a sheltered spot, gradually increasing sun and wind exposure, so they don't scorch or snap when planted out for good.
Water deeply and consistently once transplanted — irregular watering (a dry spell followed by a soak) is the most common cause of both blossom end rot (a dark, sunken patch on the fruit's base, from a temporary calcium shortage) and cracked fruit skins.
Getting a good harvest
Indeterminate varieties (the vining kind that keep growing all season) benefit from pinching out the small shoots that form between the main stem and each leaf branch ("suckers"), which redirects the plant's energy into fruit instead of extra foliage.
Fruit can be picked at the "breaker" stage, as soon as it first shows colour, and left to finish ripening indoors — useful before a frost — or left on the vine for full flavour if the season allows.
Frequently asked questions
- How long do tomato seeds take to germinate?
- About 5–10 days at 21–27°C (70–80°F). Cooler soil can stretch this to two weeks or stop germination altogether.
- Why won't my tomato seeds sprout?
- The most common causes are cold soil, sowing too deep, or letting the surface dry out. A seedling heat mat and consistently moist (not soggy) soil fix most cases.
- When can I transplant tomato seedlings outside?
- After your last frost date, once seedlings have 2–3 sets of true leaves and have been hardened off gradually over about a week.
- How long from planting to harvest?
- Roughly 60–85 days after transplanting for most varieties, or about 100–120 days total counting from seed.
- Why are my tomato leaves curling or turning yellow?
- Often inconsistent watering or heat stress. It can also signal early blight or a nutrient shortage — check the lower, older leaves first, since problems usually show there before spreading upward.