Firethorn – Pyracantha spp. Share this:Click to share on Pinterest (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window) Designed with love! Our Grower's Choice Subscription freshly picked and delivered to your door every month. Shop Now Common Name: Pyracantha, Firethorn Botanical Name: Pyracantha spp., py-ra-CAN-tha Decorative Life: Many days to weeks. Flower Color: Orange, Red, Yellow Availability: Fall, Winter Storage Specifics: 32-34F for fruited branches. A safe plant over-wintering temperature is 22F whereas 18F will kill the plant. Tidbits: From the Greek “pyr” (fire) and “akantha” (a thorn), referring to the red berries and spiny branches.