Oak Leaf Lettuce
Lactuca sativa var. crispa
Family: Asteraceae
Oak leaf lettuce is named for its distinctive deeply lobed leaves that resemble oak tree leaves. This loose-leaf variety comes in green and red types, offering tender, mild-flavored leaves that are perfect for salads. It's one of the most heat-tolerant lettuces available.
Days to Harvest
45-55 days
Sun Needs
Full Sun to Partial Shade (4-6 hours)
moderate
Germination Temp
65°F optimal
Start Indoors
4 weeks before last frost
Germination
2-10 days
Seed Depth
1/8 inch
Light to Germinate
Yes
💡 Tip: Seeds need light to germinate. Press into soil surface. One of the most heat-tolerant lettuces.
Soil Type
Rich, well-draining soil with organic matter
pH Range
6 - 7
Spacing
6-8 inches between plants, 12 inches between rows
⚠️ Avoid planting near:
History
Oak leaf lettuce is an heirloom variety that has been grown in gardens since the 1700s. Its distinctive leaf shape made it a favorite in European cutting gardens, and it remains popular today for its beauty, flavor, and heat tolerance.
Nutritional Benefits
- ✓High in Vitamin K
- ✓Good source of Vitamin A
- ✓Contains folate
Optimal Growing Temp
60°F - 70°F
Oak leaf lettuce thrives in cool temperatures but is notably more heat-tolerant than other lettuce types. Can handle temperatures up to 85°F without immediate bolting, making it excellent for extended growing seasons.
Survival Range
35°F - 85°F
Can survive these temperatures
Frost Note: Tolerates light frost (28-32°F) and brief exposure to mid-20s with protection. Young plants are more cold-hardy than mature plants.
Best USDA Zones
Humidity
40-60%
Moderate humidity preferred. Good air circulation helps prevent fungal diseases on the deeply lobed leaves.
Height
8-12 inches
Spread
10-12 inches
Growth Habit
upright
Germination
2-10 days
Seeds need light to germinate. Keep soil surface moist but not waterlogged.
Seedling Stage
Duration: 2-3 weeks
True leaves: First true leaves emerge with characteristic oak-like lobes
Transplant ready: Ready when 2-3 inches tall with 3-4 true leaves. Thin to proper spacing.
Vegetative Growth
Duration: 3-4 weeks
Rapid leaf production. Distinctive lobed shape develops fully. Begin harvesting outer leaves.
Harvest Maturity
Timing: 45-55 days from seed
- Full loose head with many lobed leaves ready for harvest
- More heat-tolerant at maturity than other types
Per Plant
6-10 oz of leaves per plant
Per Square Foot
8-12 oz when planted at proper spacing
Harvest Frequency
Cut-and-come-again every 5-7 days, or harvest whole plant at maturity
Factors Affecting Yield
- •Heat tolerance extends harvest
- •Consistent moisture
- •Regular harvesting
- •Variety selection
Seedling Stage
Daily light watering to keep surface consistently moist
Established Plants
Every 2-3 days, maintaining even soil moisture
Preferred Method
Water at soil level in morning. Drip irrigation or soaker hose ideal for keeping leaves dry.
⚠️ Critical Watering Periods
- • Germination phase
- • Hot weather periods
- • During rapid growth
Pro Tips
- Consistent moisture is critical for tender leaves
- Mulch helps maintain even soil moisture
- Water deeply but less frequently once established
- Heat tolerance is reduced if plants are water-stressed
Feeding Schedule
Organic Options
Side-dress with thin layer of compost or apply diluted liquid feed every 3-4 weeks
Minimum Size
6 inch pot minimum
Recommended Size
8-12 inch pot or window box
Depth Required
6-8 inches minimum
Best Varieties for Containers
Container Tips
- Excellent container plant with attractive lobed leaves
- Both green and red varieties grow well in pots
- Use potting mix with good drainage
- Can grow in partial shade containers
- Water consistently as containers dry faster
Why Prune
When
Begin harvesting outer leaves when they reach 4-5 inches
How Often
Every 5-7 days for continuous harvest
Technique
Cut or snap outer leaves at base, leaving center growing point and inner leaves intact
Remove
- ✗ Outer mature leaves
- ✗ Any yellowed or damaged leaves
- ✗ Leaves touching soil
Keep
- ✓ Growing center point
- ✓ At least 4-5 inner leaves
- ✓ Developing leaves
Plant Every
2-3 weeks
Sowings/Season
5-7 sowings thanks to heat tolerance
Duration
Spring through early summer, resume late summer through fall
Tips
- Start 4-6 weeks before last frost for spring crop
- Heat tolerance allows growing later into summer than other lettuces
- Resume planting 8-10 weeks before first fall frost
- Can succession plant longer than most lettuce varieties
