Lobelia will reseed themselves if you let them, but they're not invasive due to their demand for rich, loose, consistently moist soil. ... Be sure to never let your container-grown lobelia dry out.

Does lobelia come back every year?

Lobelia in winter will die back no matter which variety you have. However, the annual Lobelia may not come back at all even if it formed seed. ... The annual forms tend to get weedy when temperatures get hot in summer but can be rejuvenated by cutting the plants back by half.

Does lobelia self sow?

Lobelia tends to be a short loved perennial, but it often self sows.