How to Grow Lettuce (Even in Hot Climates)
Growing crisp, tender leaves starts with timing, cool soil, and steady moisture. This guide explains how to grow lettuce step by step, including how to grow lettuce in hot climates with shade, soil cooling, and succession planting, so you can harvest longer.
What We Will Cover
- Plant lettuce at the right time
- Choose the right varieties
- Prep rich, living soil and feed lightly but often
- Sow shallow and keep seedbeds cool and moist
- Montior the soil temperature when planting lettuce
- Water and mulch for tender, sweet leaves
- Hot-climate playbook to delay lettuce bolting
- Transplants vs direct seeding
- Container tips for growing lettuce in hot climates
- How to harvest
- Low-desert Tips
- Troubleshooting
- Quick reference: spacing and depth
- Growing Lettuce FAQ
Plant lettuce at the right time
Lettuce is a cool-season crop that grows best with daytime temperatures around 60–70°F (15–21°C). Hot, dry weather speeds up bolting and can make leaves bitter.
- General timing: Start planting 4 weeks before your last spring frost. Plant again in late summer or fall for a long cool-season harvest.
- Low desert of Arizona (9b–10a):
Succession planting lettuce is one of my favorite fall strategies. It’s one of 10 easy vegetables I always grow in my mild-winter garden.
Choose the right varieties
Try a mix so you always have something ready to harvest.
- Leaf lettuce (easiest): ‘Salad Bowl. Red,’ ‘Flashy Trout Back.’
- Romaine/Cos: ‘Jericho,’ ‘Sweety Baby.’
- Butterhead/Bibb: ‘Buttercrunch,’ ‘Tom Thumb’ (great in containers).
Trying to make it last longer in the heat? Look for words like heat-tolerant, slow-bolt, or summer crisp on the seed packet.
Prep rich, living soil and feed lightly but often
Lettuce loves fertile, moisture-retentive soil.
- Soil recipe: Work in plenty of finished compost before planting. Mix in worm castings for biology and gentle nutrients. Beds should drain well but never crust or crack.
Learn More: Best Soil for Raised Bed Vegetable Gardening; In-bed vermicomposting tips. - Fertilizer plan: Leafy crops need regular, gentle feedings. After planting, start occasional feedings with AgroThrive diluted to the label rate every 2–3 weeks during active growth. Top-dress with a thin layer of worm castings monthly and water in.
Try AgroThrive here. - Don’t overdo it: Consistent, mild nutrition beats big, infrequent doses.
Sow shallow and keep seedbeds cool and moist
Lettuce seeds are tiny and benefit from light.
- Depth: Surface sow or cover no more than ⅛ inch (3 mm). Press seeds into contact with moist soil.
- Spacing:
Leaf types: thin or transplant to 4 inches apart (10 cm)
Butterhead/Romaine: 6–8 inches (15–20 cm)
Head types: 12 inches (30 cm)
Square-foot spacing: 6 leaf types per square, 2 head types per square. - Keep evenly moist: Do not let seedbeds dry out during germination.
Learn more: How to Start Seeds Indoors
Montior the soil temperature when planting lettuce
Soil temperature drives germination and bolting.
- Germination sweet spot: 60–70°F (15–21°C). Seeds may stall at sustained soil temps above the mid-70s.
- Growing comfort zone: cool to mild conditions with steady moisture.
- Use a soil thermometer and shade the bed if soil warms too fast.
Learn more: Guide to Soil Temperatures
Water and mulch for tender, sweet leaves
Lettuce has shallow roots and dislikes swings between soggy and dry.
- Goal: Consistent moisture. Water in the morning at the soil level.
- Mulch: A thin layer of fine mulch helps cool soil and reduce evaporation.
- Containers: Check daily in warm, dry weather. Self-watering containers help maintain even moisture.
Learn More: How to Water Your Garden
Hot-climate playbook to delay lettuce bolting
When days warm or sunlight intensifies, stack the deck.
- Site selection: Morning sun with natural afternoon shade is ideal.
- Living shade: Tuck lettuce on the east or north side of taller crops.
- Succession plant: Sow a small patch every 1–2 weeks through your cool window.
- Harvest young: Take leaves smaller and more often as temperatures rise.
Transplants vs direct seeding
- Direct seeding is simple and gives compact, non-stressed plants.
- Transplants: Choose young, small plants. Oversized transplants bolt sooner. Plant at the same depth as the nursery cell.
Container tips for growing lettuce in hot climates
Shallow roots make lettuce a natural in pots and planters.
- Potting mix: Use a high-quality soilless mix. Blend in compost for water-holding and biology.
- Depth: 6–8 inches (15–20 cm) is plenty for leaf types.
- Fertilize: Light, regular feedings with AgroThrive per label.
- Placement: Bright light in cool seasons. Shift to dappled shade as heat builds.
Learn More: Container Gardening for Beginners
How to harvest
- Cut-and-come-again: Harvest outer leaves and let the center keep growing.
- Baby harvest: Shear at ½ inch above soil when leaves reach 4–6 inches.
- Heads: Cut at the base when firm and full size.
- After harvest: Rinse, spin dry, and refrigerate to hold crispness.
Low-desert Tips
- Start indoors: August to December
- Direct sow or transplant: September 15 to January
- Harvest window: Fall through spring, finishing before sustained heat
Pair fall plantings with cilantro, dill, calendula, and alyssum for beauty and beneficial insects.
Learn more: Cool-season companion plants
Troubleshooting
- Bitter leaves: Heat or drought stress. Increase watering consistency, add shade, and harvest younger.
- Bolting: Rising temperatures or oversized transplants. Switch to slow-bolt varieties, add shade, and keep soil cooler.
- Poor germination in warm soil: Start indoors in a cool room, use shade cloth over seedbeds, and water lightly twice a day until sprouted.
- Pests: Aphids and caterpillars are common. Exclude with lightweight row cover and wash aphids off with water. Encourage beneficials and skip broad-spectrum sprays.
Learn more: Prevent Garden Pests Organically
Quick reference: spacing and depth
- Seed depth: ⅛ inch (3 mm) or surface-sown and pressed in
- Leaf types: 4 inches apart (10 cm)
- Butterhead/Romaine: 6–8 inches (15–20 cm)
- Head types: 12 inches (30 cm)
- Square foot: 6 leaf or 2 head per square
Growing Lettuce FAQ
A loose, compost-rich mix that drains well but holds moisture. Blend finished compost into the top 8–10 inches and add worm castings before planting.
Every 2–3 weeks with a gentle liquid like AgroThrive at label rate. Top-dress with worm castings monthly.
Use slow-bolt or summer crisp varieties, add 30–40% shade during warm spells, keep soil evenly moist, and harvest young. Plant successions so heat never catches your only planting.
Yes. Protect young plants from rare frost with row cover and keep moisture steady. Choose varieties suited to cool weather and plant through fall and winter.
Full sun in cool seasons is great. In warm spells, give afternoon shade or filtered light.
Any suggestions for how to “fix” bitter lettuce and spinach? I’m on my first garden, and I planted spinach seeds in September and again in December. None have grown any larger than about 1 to 2″ leaves (about half the size of what’s in the store). Regardless of size, they are gross. Lettuce (romaine and leaf) planted from transplants from HD back in November. Again, they haven’t grown much and don’t taste good at all. Assuming I under-watered, causing the bitterness, is there a way to fix? Or am I out for this round?
What’s your soil like? That could be a part of it. There is still time to try to get a quick crop in if you want to try again.
So happy I found you! Question, Now that it’s April in Arizona, should I pull up my lettuce that is in ground since it has bolted and has become bitter tasting or do I just cut them down leaving the roots and put compost over them? Will they grow back in the fall?
Yes, it’s too hot for lettuce now. Rather than pull it up, cut it off at the roots and cover with compost. They won’t regrow this fall but leaving the roots in place leaves the soil undisturbed and the roots will add organic matter to the soil.
Hello Angela
I planted lettuce almost 2 weeks ago and I’m not getting any sprouting. Could it because we had this little hot spell? Also can I try replanting in the same Sq foot in say 2-3 weeks?
It’s been too hot for lettuce to germinate, you can go ahead and plant again when temps cool down.
How can you stop slugs from eating lettuce?
This blog post may have some ideas: https://growinginthegarden.com/organic-pest-control-that-really-works/
We are growing lettuce and it has germinated! We are wondering when to fertilize it, if at all? Do you recommend any reliable resources for knowing how to care for each unique plant? We also have squash
Hi Erika, I’d recommend my growing guides for each plant. I added fertilizing information to this blog post. After planting, start occasional feedings with AgroThrive diluted to the label rate every 2–3 weeks during active growth. Top-dress with a thin layer of worm castings monthly and water in.
Try AgroThrive here.