Any gardener will find it very satisfying to grow tomatoes from seeds. It’s so exciting to see those tiny seeds grow into tomato plants that can produce food.
If you’ve ever grown tomatoes from seeds, you know how exciting it is to see the first leaves come up. Tomato seeds usually sprout 5 to 10 days after planting. Once they do, the tiny seedlings grow and change quickly until they are fully grown tomato plants.
We’ll take a close look at the sprouting and early growth stages of a tomato plant in this article so you know what to expect and can give it the best care at this very important time.
Germination Stage (Days 1-10)
Germination is when the seed sprouts and the first root emerges. Here’s a step-by-step look at what happens:
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Day 1: The seed absorbs water and swells up. This kickstarts the germination process.
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Day 2-3 The radical or embryonic root emerges from the seed coat and grows downwards.
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Day 4-5: The hypocotyl, or new stem, elongates and pushes the cotyledons (seed leaves) up through the soil.
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Day 6-10: The cotyledons open and turn green. These leaves don’t look like normal tomato leaves. They are thick and oval or round in shape. The young root keeps going down, and the hypocotyl keeps arching up, which leaves the cotyledons completely above the soil.
Sprouted tomato seed with thick round cotyledons
Sprouted tomato seed with thick round cotyledons. Source: The Old Farmer’s Almanac
Pay close attention because the cotyledons emerge and open quickly. If you blink, you might miss this first stage!
Early Seedling Stage (Days 10-20)
After the cotyledons open, the plant enters the seedling stage. Here’s what to look for:
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Days 10-13: The cotyledons continue expanding and the first true leaves appear. These leaves look like normal serrated tomato leaves but they are quite small at first.
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Days 13-15: More true leaves emerge. There are now 4 leaves total – 2 cotyledons and 2 true leaves. The stem and roots begin to turn purple or green.
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Days 15-20: Additional true leaves develop. There are 6 leaves now. The seedling grows taller, the stem and roots elongate, and the root system expands downwards.
So during the second stage, you’ll notice the tomato seedling getting larger and more complex. The cotyledons provide nutrients while the true leaves start photosynthesis. Make sure the seedlings get plenty of light at this point!
Tomato seedling with 2 cotyledons and 2 small true leaves
Tomato seedling with 2 cotyledons and 2 small true leaves. Source: The Old Farmer’s Almanac
Preparing for Transplanting (Days 20-30)
In the third stage, the seedling focuses on root and foliage growth in preparation for transplanting:
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Days 20-25: The leaves and stem continue expanding upward. More true leaves emerge until there are up to 8 leaves total.
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Days 25-30: The root system spreads out filling up the container. Flower buds may begin forming. The plant looks like a miniature tomato plant now.
When the seedling fills its container with roots and has several true leaves, it’s ready to be transplanted into the garden or a larger pot. This typically occurs around 4 weeks after sowing the seeds.
Bushy tomato seedling ready for transplanting
Bushy tomato seedling ready for transplanting. Source: The Old Farmer’s Almanac
Providing Proper Care
As you monitor your sprouting tomato seeds and growing seedlings, be sure to provide proper care:
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Moisture: Keep the soil consistently moist but not soaked. Water when the top inch becomes dry.
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Warmth: Maintain temperatures around 70-80°F for optimal germination and growth.
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Light: Give seedlings 14-16 hours under grow lights or in a sunny window.
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Air circulation: Gentle air flow prevents disease. Use a small fan to circulate air.
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Fertilizer: Apply a nitrogen-rich fertilizer once true leaves emerge.
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Thinning: If more than one seed sprouts per cell, snip off the weaker ones with scissors.
With the proper environment and care, your tomato sprouts will thrive right from the start. Pay close attention to their growth stage and changing needs. The healthy seedlings you grow now will translate into a bountiful tomato harvest later!
Common Issues with Tomato Sprouts
While most tomato seeds sprout without issue, you may encounter problems like:
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Poor germination: This could be due to old seeds, incorrect soil temperature or moisture levels, or planting too deep.
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Leggy seedlings: If stems and leaves stretch and flop over, the seedling isn’t getting enough sunlight.
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Discoloration: Purpling of the stems and leaves may indicate cold temperatures or phosphorus deficiency.
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Slow growth: Inadequate light, improper hardening off, or overwatering can stunt seedling growth.
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Damping off: Fungal disease causes seeds and seedlings to rot at the soil line. Improve air circulation to prevent damping off.
Catch problems early and make adjustments to get your sprouts thriving again!
Frequently Asked Questions
Here are answers to some common questions about tomato sprouts:
How long does it take for tomato sprouts to emerge?
Tomato seeds usually germinate in 5-10 days after planting. The timeframe depends on soil temperature, planting depth, and seed age.
What do tomato sprouts look like?
When seeds first sprout, you’ll see two green, oval cotyledon leaves rising up out of the soil. The stem and roots will be white.
How many leaves do tomato sprouts have?
Tomato sprouts start with just two cotyledon leaves. Within two weeks, they develop 2-4 true leaves for 4-6 leaves total. More true leaves continue emerging after that.
Can you transplant tomato sprouts?
Tomato sprouts can be transplanted once the root system fills the container and they have at least 2-4 true leaves. This usually occurs 3-4 weeks after germination.
Why are my tomato sprouts turning purple?
Purpling of the stems and leaves indicates cool temperatures below 55°F. This isn’t harmful but seedlings grow best with warmer 70-80°F temperatures.
Conclusion
Paying close attention to your tomato plants as soon as they sprout is crucial. Look for the cotyledons to emerge first, followed by the growth of true leaves and branching of the main root and stem. Providing proper moisture, warmth, and light ensures your sprouts transition smoothly into healthy seedlings ready for transplanting. With a little care, your tiny sprouts will soon become mighty tomato plants!
Tomato Growing Stage #4: Flowering Stage
In 5-7 weeks after germination, tomato plants step into the flowering stage with noticeable small yellow flowers and height reaching 12 to 18 inches tall. Indeterminate tomato types may flower a little later than other types, but they will keep flowering and producing fruit until the end of the season. Determinate varieties, however, produce all their fruit over a shorter period.
When flowering begins, pay attention to supplying your tomato plants with the following essentials:
- Optimal temperatures for flowering are between 70-85°F (21-29°C). Extreme temperatures can make flowers not open or fall off too soon.
- Hold on to the light. For tomato plants to flower and produce fruit, they need at least 6 to 8 hours of direct sunlight every day. If unavailable, use indoor grow lights instead.
- Good nutrition is still recommended, but this time, use less nitrogen and more phosphorus to help flowers grow in a healthy way.
Tomato Growing Stage #1: Germination
Here we are – the first actual stage of tomato growing phases. Generally, tomato seeds start to sprout in 5-10 days after planting. However, you can expect to see the sprouts in 6-8 days with Spider Farmer seed starter trays.
Once the seed germinates, it develops a tiny root called the radicle, which emerges and grows downwards into the soil. Shortly after, a small shoot pushes its way up through the soil surface, seeking light. Along with the shoot are two small, oval-shaped leaves called cotyledons. These are the seed leaves and are typically the first signs of life above the soil. Fascinating, isn’t it?.
To germinate effectively, tomato seeds require the following conditions:
- Maintain a consistent temperature of 70-75°F (21-24°C). The highest you dare to try is 85°F (29°C). Anything higher than that would probably keep seeds from getting the water they need to grow.
- Keep the soil consistently moist but not water-soaked.
- Tomato seeds do not require light to sprout.