Lettuce is one of the easiest crops you can grow in your garden. That holds true whether you love full lettuce heads or baby lettuce leaves. Even if you garden in containers, you can have a bumper crop of leafy greens. Follow these tips on how to grow lettuce and leafy harvests and homegrown salads will be on your table soon enough.
When spring arrives, lettuce is one of the earliest crops you can plant outdoors. As soon as your soil is ready to be worked, lettuce seeds are good to go. Lettuce comes in many varieties, from head-forming butterheads to leaf lettuces that never form heads. You can even buy premixed seed packets that include colors from green to purple-red and textures from smooth and soft to crisp and heavily ruffled. Lettuce seeds can germinate with soil temperatures of just 40 degrees Fahrenheit — not far above freezing. But lettuce plants grow best when air temperatures reach 60°F to 65°F.1 Like cabbage and other cool-loving vegetables, lettuce flourishes in cool spring weather, then lets you do it all again come fall. There are even lettuce varieties that tolerate more heat, but most lettuces grow tough, dry and bitter in summer heat. Head-forming lettuces like romaine and butterhead take longer to grow and harvest than leafy lettuces. Spring is a race for heads to mature before temperatures rise too high. Many gardeners start their head lettuce seeds indoors to extend their growing season. Some garden centers offer small seedlings called transplants that accomplish the same goal. In contrast to head-forming lettuces, leafy types are much easier: Seed them straight into spring garden soil.
Lettuce is a cool-season crop that can be grown in early spring and fall in most climates. Many gardeners like to get a head start on the growing season by starting lettuce seeds indoors or in a greenhouse. This allows the seedlings to mature faster before transplanting them into the garden. But when is the right time to transplant lettuce seedlings outdoors?
What to Consider Before Transplanting Lettuce Seedlings
There are a few key factors to consider when determining the best time to transplant lettuce seedlings into the garden
Age of the Seedlings
Lettuce seedlings should be 4-6 weeks old before transplanting This allows time for the root system to establish so the seedlings can better withstand transplant shock Seedlings that are younger than 4 weeks may struggle to adapt to outdoor conditions,
Number of True Leaves
Look for lettuce seedlings to have 2-4 true leaves before transplanting. The first leaves that emerge are called cotyledon leaves. Once the first set of true leaves emerges, the plant is ready for transplanting. This indicates the root system is developed enough.
Hardening Off
Lettuce seedlings should be “hardened off” for 7-10 days before transplanting. This means gradually exposing them to outdoor conditions like sun, wind, and cool temps. Hardening off toughens up the tender seedlings.
Soil Temperatures
Lettuce thrives in cool weather. Transplant seedlings once soil temperatures are 45-75°F (7-24°C). Temperatures on the warmer end of this range will cause lettuce to bolt quickly.
Frost Danger
Avoid transplanting until after the last spring frost has passed. Lettuce can tolerate light frosts, but hard freezes will damage young seedlings. Wait 2-3 weeks after the final frost date for soil to warm up before transplanting.
Spacing
Make sure to space lettuce plants properly, 10-12 inches apart in all directions for head lettuce and 4-6 inches for leaf lettuce. This prevents overcrowding and allows for full growth.
When to Start Lettuce Seeds Indoors
Count backwards on your calendar based on the ideal transplant timing to determine when to start your lettuce seeds:
- Start seeds indoors 4-6 weeks before transplanting
- Allow 7-10 days to harden off before transplanting
- Transplant 2-3 weeks after last spring frost date
- Add 1-2 weeks as a buffer
Here are some examples for common last spring frost dates:
| Last Frost Date | Start Seeds | Start Hardening Off | Transplant Outdoors |
|---|---|---|---|
| March 15 | February 1 | March 7 | March 25 |
| April 15 | March 1 | April 7 | April 25 |
| May 15 | April 1 | May 7 | May 25 |
These dates will vary based on your local climate and weather patterns. Check your specific last frost date before determining your schedule.
How to Transplant Lettuce Seedlings
Follow these steps when the time comes to transplant lettuce seedlings into the garden:
Prepare the Garden Bed
- Choose a spot that gets full sun (at least 6 hours per day)
- Loosen the soil and mix in 1-2 inches of compost
- Space rows 12-18 inches apart
- Water soil before transplanting
Harden Off Seedlings
- Place seedlings outdoors in partial shade for a few hours
- Slowly increase sun exposure over 7-10 days
- Bring seedlings indoors overnight until transplant day
Dig Holes for Transplants
- Use a trowel to dig holes the same depth as seedling cells
- Space holes 10-12 inches apart for head lettuce varieties
- Space 4-6 inches apart for loose leaf lettuce
Carefully Transplant Seedlings
- Gently remove from cells, handling by leaves to avoid stem damage
- Place each plant in a hole, backfill with soil to cover roots
- Firm soil gently and water transplants immediately
Provide Ongoing Care
- Water regularly until plants are established, about 2 weeks
- Add mulch to conserve moisture
- Monitor for pests like slugs or aphids
Proper transplanting technique and aftercare ensures the best start for your lettuce transplants. With the right conditions, your lettuce will flourish!
Common Problems When Transplanting Lettuce
Here are some potential issues to watch for when transplanting lettuce seedlings:
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Transplant shock – Wilting and poor growth due to trauma to roots. Harden off seedlings properly and limit root disturbance during transplanting.
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Leggy seedlings – Elongated stems from inadequate sunlight. Provide 16 hours of light per day for indoor seedlings. Transplant a bit deeper to support weak stems.
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Root damage – Carefully handle seedlings by the leaves when transplanting to avoid tearing delicate roots. Dig holes deep enough to accommodate entire root system.
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Damping off disease – Fungal issue causing seedling collapse. Avoid overwatering and provide good airflow. Disinfect reused trays/pots.
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Bolting – Premature flowering. Transplant on schedule to sizeable plants, provide consistent moisture, and avoid letting lettuce get too large before harvesting.
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Slow growth – Stunted plants from cold temperatures or shock. Warm soil before transplanting and harden off seedlings appropriately.
With proper timing, technique, and aftercare, transplanting lettuce seedlings can be done seamlessly. Pay close attention to plant signals and garden conditions for success. Then you’ll be harvesting homegrown lettuce in no time!
HOW TO PLANT AND TRANSPLANT LETTUCE
Lettuce is one of the few vegetables that tolerates a bit of shade. A planting site with full sun and late-afternoon shade is ideal — especially as summer nears. Well-drained soil with rich organic matter provides the perfect foundation for all lettuce types. Before you plant, mix organic compost and a balanced fertilizer such as Pennington Rejuvenate Plant Food All-Purpose 4-4-4 into your soil. Lettuce grows best when soil pH is between 6.0 and 7.0, the range where most plants thrive.
Lettuce transplants are garden-ready when theyre three to four weeks old. Gradually acclimate transplants to the outdoors before you plant. Transplant head types such as romaine, iceberg and butterhead at 10- to 12-inch intervals, in rows 15 to 18 inches apart. If youre planting in pots or in mixed gardens, allow similar space. For leaf lettuces, sow seed into garden soil. Plant four to six lettuce seeds per inch, in rows at least 2 inches apart. Many gardeners plant swaths of lettuces a foot wide — just keep widths manageable for harvesting. Lightly cover lettuce seeds with 1/8 inch of soil and press gently to ensure good seed-to-soil contact. Depending on the variety, most lettuces mature between 30 and 60 days after planting. Your seed packet will specify whats normal for the lettuces you choose. Plant fall lettuce four to eight weeks before your areas first expected fall frost. For near-continuous spring and fall lettuce crops, plant seeds in succession plantings every two to three weeks.
Head-forming lettuces take longer for harvest than loose-leaf types.
How to Transplant Lettuce Seedlings for HUGE Results
FAQ
How tall should lettuce seedlings be before transplanting?
Lettuce transplants are garden-ready when they’re three to four weeks old. Gradually acclimate transplants to the outdoors before you plant. Transplant head types such as romaine, iceberg and butterhead at 10- to 12-inch intervals, in rows 15 to 18 inches apart.
Can you transplant lettuce seedlings?
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1. Prepare the Planting Area:Prepare your garden bed or container with well-draining soil and add fertilizer if needed.
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YouTube · BernadettesGardenhttps://www.youtube.comHow to Transplant Lettuce Seedlings You Grew From Seed! – YouTubeFeb 7, 2014 — gardening and crafting with Bernardet transplanting lettuce in Michigan we are often able to transplant our winter lettuce in February for a March ha…
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Kansas Healthy Yardshttps://kansashealthyyards.orgKansas Healthy Yards – Transplanting Lettuce to the Garden
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Gardener’s Supplyhttps://www.gardeners.comGrowing Lettuce Indoors Year-Round | Gardener’s SupplyMar 27, 2025 — 5 Steps to Growing Lettuce Indoors * Choose your container, growing medium and seeds. Lettuce seedlings at two weeks. Flat, fairly shallow containe…
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2. Gently Remove Seedlings:Carefully remove the seedlings from their containers, holding them by the leaves and not the stems.
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3. Create Planting Holes:Use your finger or a dibber to create holes that are deep enough to bury the seedlings up to their first set of true leaves.
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4. Transplant and Water:Place the seedlings into the holes, gently press the soil around them, and water thoroughly.
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5. Space the Seedlings:Space the seedlings according to their mature size. For leaf lettuce, 4-6 inches apart is a good guideline.
When can I put lettuce seedlings outside?
Direct sowing is recommended. Sow seeds in the ground 2 to 4 weeks before your last spring frost date or as soon as the ground can be worked. Or, to get a head start, start seeds indoors about 1 month before your last spring frost date. Harden off seedlings for 3 days to a week before setting outdoors.
How big should seedlings be before transplanting?
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Height:Seedlings should be at least 2-3 inches tall, but the height can vary slightly depending on the plant species.
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True leaves:Seedlings should have at least 3-4 true leaves. True leaves have the shape and texture of mature leaves, unlike the cotyledons (seed leaves) that emerge first.
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Root development:The seedling’s root system should be well-established and strong enough to support the plant when transplanted. A good way to check is to gently lift the seedling from its container. It should lift cleanly with the soil clinging to the roots, not crumble.
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Hardening off:Before transplanting outdoors, it’s often beneficial to harden off seedlings by gradually acclimating them to the outdoor environment (e.g., by starting them outdoors in partial shade and gradually increasing the amount of sunlight they receive).
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Container size:If seedlings are starting to outgrow their initial container or tray, that’s another sign they’re ready for a bigger pot or the garden.