- Name: Firecracker Penstemon - Other Common Names: Eaton's Penstemon - Scientific Name: Penstemon Eatonii - Color: Firecracker Red - Plant Seeds: Outdoors After Frost / Indoors Weeks Before Last Frost - Bloom Time: Spring - Hardiness Zone: 4 - 8 - Plant Height: 12 - 36" - Plant Spacing: 12 - 18" - Light Requirements: Sun - Soil& Water Preferences: Average - Dry - Quantity:150 Seeds - Other: The Firecracker Penstemon Is An Absolute Favorite Of Hummingbirds! It Is Their Favorite Color, And The Long Tube Shaped Flowers Are Just Perfect For Their Long Beaks. The Flowers Are A True Bright Red, And Will Add Tremendous Splashes Of Color To Your Flower Gardens.