If you’re planning your Oklahoma garden, knowing when to plant lettuce is the key to a long, productive harvest. Getting the timing right means you can enjoy crisp, homegrown salads for much of the year, and it all starts with understanding our unique climate.
When to Plant Lettuce in Oklahoma – Best Planting Times for
Oklahoma’s weather can be tricky, with late frosts in spring and early heat in summer. Lettuce is a cool-season crop, so it thrives in the milder temperatures of spring and fall. The goal is to plant it so it matures before the intense summer heat arrives, or as the heat breaks in autumn.
Understanding Oklahoma’s Planting Zones
Oklahoma spans USDA hardiness zones 6a to 8a. This range affects your exact planting dates. Gardeners in colder zone 6 (like Panhandle areas) will plant a bit later in spring and earlier in fall. Those in warmer zone 8 (southeastern OK) can plant earlier in spring and later in fall.
- Zone 6a & 6b: Average last spring frost around April 15-25. Average first fall frost around October 15-25.
- Zone 7a & 7b: Average last spring frost around April 1-15. Average first fall frost around October 25 – November 10.
- Zone 8a: Average last spring frost around March 22 – April 1. Average first fall frost around November 10-20.
Spring Planting Schedule
For a spring crop, you need to get lettuce in the ground early. The soil must be workable—not too wet or frozen. A common method is to plant seeds directly in the garden as soon as the soil can be worked, which is usually 4-6 weeks before the last average frost date.
- Direct Seed Outdoors: Late February to Mid-March for southern OK. Mid-March to Early April for northern OK.
- Transplant Starts: You can get a head start by using transplants. Set these out 2-3 weeks before the last frost date, typically from early March to early April.
Succession planting is your friend here. Sow a new, small row of seeds every 10-14 days to extend your harvest window into early summer.
Fall Planting Schedule
Fall is often the best time for lettuce in Oklahoma. The cooling temperatures and fewer pests make for ideal growing conditions. The trick is to calculate your planting date by working backward from your first average fall frost.
- Direct Seed Outdoors: Start planting fall lettuce seeds in mid-August through September. For leaf lettuces, aim for 6-8 weeks before the first frost. For heading types like romaine, allow 10-11 weeks.
- Transplant Starts: In late summer heat, it can be easier to start seeds indoors or in a shaded spot. Transplant these seedlings into the garden in September when temperatures begin to cool.
Using shade cloth for your late summer plantings can protect young seedlings from intense sun and help the soil retain moisture.
Step-by-Step Planting Guide
1. Choosing Your Lettuce Varieties
Pick varieties suited for Oklahoma’s swings. Heat-tolerant and slow-bolting types are excellent for spring. For fall, you have more flexibility.
- Great Spring Varieties: Black Seeded Simpson, Jericho Romaine, Summer Crisp varieties like ‘Magenta’.
- Reliable Fall Varieties: Any spring variety, plus Buttercrunch, Romaine, and Oakleaf.
- Winter Harvest: In protected cold frames, try hardy varieties like Arctic King or Winter Density.
2. Preparing Your Soil
Lettuce has shallow roots and apreciates loose, fertile soil. Work in 2-3 inches of compost or well-rotted manure before planting. The soil pH should be between 6.0 and 7.0. A balanced, all-purpose fertilizer mixed into the soil at planting gives seedlings a good boost.
3. Planting the Seeds or Transplants
- Sowing Seeds: Plant seeds only 1/4 inch deep. Space them about 1 inch apart in rows 12-18 inches apart. You’ll thin them later.
- Setting Transplants: Dig a hole just larger than the root ball. Space plants according to their mature size: 6-8 inches apart for leaf lettuce, 10-12 inches for romaine and butterhead.
- Watering In: Gently water the seeded area or transplants immediately after planting. Keep the soil consistently moist for germination and establishment.
4. Ongoing Care and Maintenance
Once your lettuce is growing, consistent care is simple but important.
- Watering: Provide 1-1.5 inches of water per week. Drip irrigation or soaker hoses are best to keep leaves dry and prevent disease.
- Thinning: When seedlings are a few inches tall, thin them to the proper spacing. You can eat the thinnings!
- Fertilizing: Side-dress with a nitrogen-rich fertilizer (like blood meal) 3 weeks after transplanting or when plants are half-grown.
- Weeding: Weed regularly but carefully, as lettuce roots are shallow and easily disturbed.
Protecting Lettuce from Oklahoma Weather
Our weather is the biggest challenge. Here’s how to manage it:
- Late Spring Frost: Have row covers or old bedsheets ready to drape over plants on cold nights.
- Early Summer Heat: Heat causes lettuce to “bolt” (send up a flower stalk), making it bitter. Use shade cloth to protect spring crops as temperatures rise above 75°F.
- Heavy Rain: Ensure your garden has good drainage to prevent root rot. Raised beds are ideal for this.
Harvesting Your Lettuce
You can start harvesting leaf lettuce as soon as leaves are big enough to eat—just pick the outer leaves. For head lettuce, wait until the head feels firm. The best time to harvest is in the cool morning when leaves are crispest. If you harvest in the heat of the day, leaves can be limp.
For the fall garden, you can often harvest lettuces right up untill a hard freeze. Some cold-tolerant types may even survive the winter under a thick layer of mulch or in a cold frame, giving you a very early spring harvest.
Common Problems and Solutions
Watch out for a few typical issues:
- Bolting: Caused by heat and long days. Plant at the right time and use shade cloth. Choose slow-bolt varieties.
- Slugs and Snails: They love tender lettuce. Use organic bait, beer traps, or hand-pick them in the evening.
- Aphids: Blast them off with a strong stream of water or use insecticidal soap.
- Tipburn: Brown edges on leaves often indicates uneven watering or a calcium deficiency. Maintain consistent soil moisture.
FAQ: Lettuce Planting in Oklahoma
Can I grow lettuce in Oklahoma in the winter?
Yes, with protection! Using cold frames, hoop houses, or thick mulch, you can grow cold-hardy varieties for winter harvests, especially in zones 7 and 8.
What is the latest I can plant lettuce in the fall?
You can plant seeds up until about 6-8 weeks before the first hard frost for leaf types. Using transplants can extend this deadline a little, as they mature faster.
Why did my lettuce seeds not germinate?
Lettuce seeds need cool soil (ideal is 55-70°F) and light to germinate. If planted too deep or in soil that’s too warm, they will fail. In late summer, try pre-cooling seeds in the refrigerator before sowing and keep the seedbed shaded and moist.
Can I grow lettuce in containers?
Absolutely. Lettuce is perfect for pots on a patio. Ensure the container is at least 6-8 inches deep and has good drainage. You might need to water container lettuce more frequently.
By following these timing guidelines and tips, you’ll be able to enjoy fresh, homegrown lettuce from your Oklahoma garden for many months of the year. Just remember the golden rule: keep it cool, and keep it consistent.