25 False Blue Indigo Seeds False Blue Indigo is best planted in late summer from fresh seeds directly in the garden due to their large tap root. Long-lived plant once established. For easier germination, soak in hot water 24 hours before planting. Growing Conditions Light: Full/Part Sun Perennial: Zones 3-9 Height: 3 feet Spread: 3 feet Bloom: Early Summer Critters: Deer, rabbit, groundhog resistant