77-84 Days to maturity. Lobelia erinus. Cambridge Blue Lobelia Seeds. Non-GMO, open-pollinated, Premium Quality Seeds, annual. Open Pollinated. Cambridge Blue lobelia is brilliant, easy to grow from seed, and perfectly suited for many humid and temperate climates. Cambridge Blue seeds will excite your home, patio, and garden with fast-growing 4-6 inch tall lobelia with half-inch tubular powder blue blooms. About 520,000 seeds per ounce.