How to Grow Undulata Lettuce
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Undulata Lettuce
Lactuca sativa var. crispa 'Undulata'
vegetableUndulata is a frilly, curly leaf lettuce variety known for its deeply ruffled and wavy foliage that creates an attractive, ornamental appearance. The light green leaves are tender and mild-flavored, making it popular for fresh salads and garnishes. It matures relatively quickly and can be harvested as cut-and-come-again greens or full heads.
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Example Undulata Lettuce timeline · Pittsburgh, PA (Zone 6b)
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Plant Undulata Lettuce
Around Apr 17Near Pittsburgh's average last spring frost.
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Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
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Harvest Undulata Lettuce
Around Jun 1≈ 45 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Undulata Lettuce dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 3-9; cool-season crop grown spring and fall in warm climates
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Get my Undulata Lettuce timeline →Growth Stages
Seedling
10-14 daysTiny cotyledons emerge within 7-10 days. First true leaves develop with characteristic wavy margins becoming visible.
Maintain consistent moisture and warmth (60-70°F). Thin seedlings to proper spacing once they have 2-3 true leaves. Provide bright light to prevent leggy growth.
Vegetative Growth
20-30 daysMultiple deeply ruffled leaves develop from the center. Plant forms a rosette of soft, wavy foliage. Leaves remain tender and light green.
Maintain consistent watering and cooler temperatures (60-65°F). Feed with diluted liquid fertilizer every 2 weeks. Begin thinning outer leaves for cut-and-come-again harvest if desired.
Leaf Development
15-20 daysNumerous layers of frilly, undulating leaves create a full, attractive head. Foliage density increases significantly. Plant reaches near-mature size.
Continue consistent watering and cool conditions. Provide afternoon shade in warm weather (above 70°F) to delay bolting. Remove any yellowing lower leaves.
Maturity
Variable; ready to harvestFull-sized head with maximum ruffled leaf development. Leaves maintain tender texture and mild flavor. Plant is ready for harvest.
Check regularly for bolting (flower stalk emergence). In cool conditions, mature heads can remain harvestable for 1-2 weeks. Water consistently to prevent bitterness.
Bolting
Occurs when triggered by heat or long daysIf temperatures exceed 75°F or daylight lengthens, a central flower stalk begins to emerge. Leaves become bitter and tougher.
Harvest immediately once bolting begins. Remove bolting plants to prevent self-seeding (unless saving seed). In spring/fall crops, bolting is usually delayed.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
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Spray with strong water stream, insecticidal soap, or neem oil. Encourage beneficial insects like ladybugs.
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and
(Gastropoda)
Hand-pick in early morning or evening, use beer traps, copper barriers, or food-grade diatomaceous earth around plants.
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Yellow sticky traps, insecticidal soap, neem oil, or reflective mulch. Remove heavily infested leaves.
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Remove affected leaves promptly. Use fine row covers to prevent adult flies. Remove debris where pupae overwinter.
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Improve air circulation, avoid overhead watering, ensure proper spacing. Use fungicides containing sulfur or copper if severe.
Uses
Fresh Salads & Garnish
CulinaryUndulata's attractive ruffled leaves make it a visual centerpiece in fresh salads. The tender, mild flavor pairs well with light vinaigrettes and delicate toppings. [source]
Nutritious Greens
CulinaryHigh in vitamin K, folate, and vitamin A, providing antioxidants and dietary fiber. The waxy leaf surface helps retain moisture and nutrients. [source]
Ornamental Edible Planting
HouseholdThe deeply undulating, frilly foliage adds aesthetic appeal to ornamental vegetable gardens and landscape borders. Can be grown purely for decorative purposes. [source]
Light Cooking & Wilting
CulinaryTender leaves can be gently wilted into soups, pasta dishes, or sautéed with light oils and garlic. Maintains delicate flavor when cooked briefly. [source]
Pollinator & Beneficial Insect Support
WildlifeIf allowed to bolt, Undulata produces small yellow flowers that attract pollinators and beneficial insects to the garden. [source]
Harvest Tips
Begin harvesting outer leaves when 4-6 inches long (cut-and-come-again method) for continuous production, or wait 45-60 days and harvest entire head at soil level with a sharp knife in early morning for maximum crispness. For best quality, harvest before temperatures exceed 75°F. Heads are most tender and flavorful when harvested young.
Fun Facts
- 🌱 Undulata lettuce is an Italian heirloom variety whose name literally means 'wavy' or 'undulating' in Latin, referring to its distinctively crimped and ruffled leaf margins.
- 🌱 The frilly leaf structure of Undulata provides more surface area than smooth-leafed varieties, making it ideal for trapping salad dressings and improving flavor distribution.
- 🌱 Lettuce is one of the oldest cultivated vegetables, with evidence of consumption dating back to ancient Egypt around 2680 BC, and today hundreds of lettuce varieties exist worldwide.
Gardening Terms
New to gardening? Learn about terms used in this guide:
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