Red Cardinal Flower Seeds

Cold stratification is required for Lobelia Cardinalis seeds; skip it, and you'll get near-zero germination rate. For that just mix cardinal flower seeds with damp sand or peat moss, seal them in a zip bag, and refrigerate them for 8 weeks. After that sow Red Cardinal flower seeds on the surface of moistened seed starting mix, pressing them down gently. Don't cover  seeds, as light is required to trigger germination. Keep them at 65-70°F and maintaining constant moisture on the surface. Cardinal flower seeds starts to sprout in 2-3 weeks. Sow them indoors 8-10 weeks before the last expected frost if you want to see blooms the first year.

Lobelia Cardinalis seeds thrive in full sun, but partial shade is works as well, especially where afternoon heat is brutal. This is not a drought-tolerant plant. Dry soil stunts growth and induces premature dormancy, which is why Lobelia Cardinalis grows so well in areas where it's naturally exposed to moisture, such as pond edges and stream banks. For the garden, a well-draining, organically enriched soil with a loamy texture is ideal. For container gardens, be prepared to water daily. If your site drains fast, amend with compost before planting.

Deadhead Red Cardinal flowers to prolong blooming, but leave a few spent spikes up for self-seeding. Divide every 2-3 years in early spring, as old plants become woody and the blooms becomes poor. The Cardinal plant is deer and rabbit resistant, so it's great for a mixed perennial borders. One application of balanced fertilizer in the spring is all it needs, after that keep it moist  and it will take care of itself.