Palm
Bismarck Palm
Bismarckia nobilis · Arecaceae
Also called: Bismark Palm
Bismarck Palm (Bismarckia nobilis) is a low-water palm well suited to Tucson and the low desert. It thrives in full sun, with a slow to moderate growth rate.
Bismarck Palm at a glance
- Water use
- Low (established)
- Sun
- Full sun; tolerates reflected desert heat. Best in a wind-protected spot.
- Mature size
- 30-40 ft tall (up to ~50-70 ft over many decades) and 12-16 ft wide canopy in the low desert
- Growth rate
- Slow to moderate
- Bloom
- Inconspicuous; small cream to brownish flowers (palms are dioecious). Females bear brown to dark fruit., Late spring to summer (flowers ornamentally insignificant; grown for foliage)
- Cold hardiness
- Cold-hardy to about the mid-20s F; can be foliage-damaged in the low 20s and regrow from rare freezes near 25 F. Frost-protect young palms during hard Tucson freezes; mature trunked specimens are quite frost-resilient. Suited to USDA 9a-9b.
- Soil
- Tolerant of a wide range of soils but demands good drainage; handles Tucson's alkaline, rocky, caliche-prone soils. Avoid standing water.
- Native range
- Madagascar
- Best used as
- Dramatic specimen/focal palm, Large-scale landscapes, resorts, and commercial entries, Xeriscape and desert-modern designs
- Wildlife
- Limited wildlife value; fruit may be eaten by birds. Flowers offer minor pollinator interest.
- Toxicity
- Not considered toxic to people or pets; the silvery fronds are stiff and can be a physical hazard.
How to grow Bismarck Palm in Tucson & the low desert
Watering
Deep, infrequent irrigation. Water established palms deeply every 7-14 days in summer and roughly monthly in winter; deep watering pushes roots down and improves drought and wind stability. Young palms need more frequent water for the first 1-2 years.
Fertilizer & nutrients
Apply a specialty palm fertilizer (slow-release, ~8-2-12 with extra magnesium and micronutrients) 2-3 times during the warm season (spring, early summer, late summer). Watch for potassium and manganese deficiencies, which show as frizzled or yellowing fronds in alkaline desert soils.
Pruning & care
Low maintenance. Remove only fully dead/brown fronds; never over-prune (no 'hurricane cut'). Removing green fronds stresses the palm and worsens nutrient deficiency. The persistent leaf bases and old fronds are best left until naturally brown.
Notes
The signature steel-blue 'silver' form is the most prized for the desert; a green form exists. Needs significant space - the massive crown and wide trunk make it unsuitable for small yards or near walls. One of the best large blue palms for Tucson's heat. Dioecious (separate male and female plants).
Sources: Arizona State University (camartin) plant database - Bismarckia nobilis; University of Arizona CALS Arboretum taxon records; Mountain States Wholesale Nursery / regional low-desert nursery guidance; Gardenia.net - Bismarckia nobilis