Needle Palmis a bush type palm, the sole member of the genus Rhapidophyllum. Sometimes called hedgehog palm, blue palmetto.It is the most cold-hardy palm in the world.
The scientific name Rhapidophyllummeans "needle-leaf", while hystrix is from the scientific name of a genus of porcupines. The English name likewise refers to the 4 to 8 inch long needle-like spines produced at the petiole bases; for similar reasons, it is also occasionally called "porcupine palm".
The Needle Palm assumes a shrub like clumping form with several stems growing from a single base, the stems growing very slowly and tightly together, eventually forming a dense base 3 to 4 feet The whole plant can reach 4 to 8 feet tall to the top of the erect central leaves. It is a fan palm (Arecaceae tribe Corypheae), the leaves with a long petiole terminating in a rounded fan of 8 to16 leaflets; each leaf is up to 2 m long, with the leaflets up to 60–80 cm long.
The Needle Palm is very popular among palm enthusiasts in temperate climates for its extraordinary ability to tolerate cold. Reports have claimed survival of temperatures as low as-20 degrees F, although more realistic estimates are approximately 5 degrees F to minus - 5 degrees F. Younger or potted plants are less hardy and may need protection on colder nights. Needle Palms prefer hot, humid summer temperatures to thrive. To plant and grow them in the Pacific NW you will need to mix top soil (potting soil) 50 / 50 with a sand & small gravel mix Have the root ball raised about 1/4 out of the hole but mounded up with the soil mixture. Try not to get the trunk wet when watering. I recommend using a water meter the first year. They usually only need to be watered in the summer months and then only when young or after transplanting. (may need some protection on colder winter days)