Botanical Name: Lactuca sativa, Brassica rapa, Eruca sativa
Days to Maturity: 20–45 days
Native: UnUnknown; lettuce has been in cultivation for a long time.
Hardiness: Frost-tolerant annuals
Plant Dimensions: Leaves are harvested at 4″–6″ tall for mesclun.
Variety Information: LEAF LETTUCES: ‘LOLLA ROSA’: Deeply curled leaves with very frilly, red edges. ‘OAK LEAF’: Medium green, deeply lobed, oak leaf-shaped leaves with mild flavor, and slower to bolt. ‘BLACK SEEDED SIMPSON’: Crinkled, light green, crisp leaves with frilly edges. SUMMER BIBB LETTUCE: Soft, slightly crumpled light-green leaves in a loose head, often with a creamy yellow core. GREENS: ARUGULA (rocket salad): Medium green, deeply lobed leaves are rich and peppery with a hint of nut. MUSTARD, ‘MIZUNA’: Thin stems, serrated light green leaves with slightly peppery, mildly spicy flavor. BOK CHOY, ‘TATSOI’: Thick, dark green leaves with a milder flavor than western head cabbage.
When to Sow Outside: RECOMMENDED. 2 to 4 weeks before your average last frost date, and when soil temperature is at least 40°F, ideally 60°–70°F. Successive Sowings: Every 3 weeks until 2 weeks before your average first fall frost date. Mild Climates: Sow in fall and winter for cool season harvests.
When to Start Inside: Transplanting is not recommended, although mesclun can be grown indoors on a sunny windowsill or under grow lights.
Days to Emerge: 5–14 days
Seed Depth: Surface to ⅛”
Seed Spacing: Broadcast about ½” apart
Thinning: Not required for baby greens
Harvesting: Harvest leaves with scissors 2″ above the soil surface. Mesclun will regrow and provide 2–3 harvests, although the first harvest is usually the best. If you wish to harvest mature heads, cut off at 2″ above ground level as soon as possible after head forms; new leaves will grow form the center. The earlier the harvest, the more tender the crop.