Cardinal flower produces spikes of bright red flowers late in the summer. Grow the plant near water as it prefers moist soils.
Lobelia grows best in partial shade and needs winter protection.
Remove the first flower spike as it fades to encourage side shoots which extend the blooming season. Fertilize when the first flower spike is removed. Seed sown in autumn will give plants which bloom in early spring. The seed germinates in 3 to 4 weeks at temperatures between 68 and 86 degrees. Division may be done in early fall or spring.