Great hardy plant for rain gardens or other moist areas. Lovely blue-purple flowers attract bees and other pollinators. Can be a short-lived perennial; may spread seed enthusiastically.
Reportedly planting it in a shadier area will give more intensely-colored blooms.
Cold stratification / winter sowing is helpful.
By our calculations*, you should look at sowing Great Blue Lobelia about 105 days before your last frost date .
Native habitat – often found near or on stream banks.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Great Blue Lobelia is a very hardy plant.Allow pods to dry on plant, then collect. Or just shake the plant around to distribute seeds nearby.
These estimates for how long Great Blue Lobelia takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.
Average 20 days | Min 6 days | Max 88 days (9)
Average 96 days | Min 65 days | Max 160 days (4)
Average days | Min days | Max days (0)
Our when to plant Great Blue Lobelia estimates are relative to your last frost date.
Great blue lobelia
Lobelia siphilitica L.