55-65 Days to maturity. Lactuca sativa. Sweet Valentine Romaine Lettuce Vegetable Seeds. Non-GMO, annual, open-pollinated, heirloom romaine lettuce. Sweet Valentine romaine lettuce is an adorable addition to any salad garden. It features a lovely light-green to pinkish-red tinge along the outer leaves. It also grows in a compact, crisp bunch, typical of romaine. The flavor is sweet, mild, and fresh. It's known for being slow to bolt, which means it can tolerate some heat better than other varieties, making it a good choice for late spring planting or warmer climates. ~3,000 seeds/oz.