Palms For California

Pronunciation: kahr-ee-OH-tuy ob-TOO-suh

Common Name: Giant Black Fishtail Palm; Giant Fishtail Palm; Thai Mountain Giant Palm

Caryota obtusa is one of the most striking, spectacular and space-occupying palms one can grow in California, but it is a giant and needs plenty of room to 'spread its wings'. A well grown tree is hard to beat as specimen palm. Palms grown in crowded gardens or in groups of several diminishes the amazing leaf spread of each individual plant. There are many mature examples of this Thailand native growing all over California and many are flowering and dying already, despite this being a relatively new palm in the late 1900s. Some sources state these live 25 years before flowering, and grow up to 60 of trunk. So far, neither seems to be the case in California. Most trees flower after 10-15 years, and few make it over 20'-30' of trunk before starting to flower. These trees have exceptionally hard wood trunks making their removal a huge chore. Still, they are amazing beautiful palms.

Synonym: Caryota gigas (which has been the real name and and which the synonym has bounced back and forth several times)

Appearance and Biology Habit: solitary with a crown of 4-6 very wide bipinnate leaves Height: 30'-40' (plants nearer the coast tend to grow taller than those inland) Trunk: single; 25"-30" thick; ringed; clean; top covered with black fiber (below and among leaf crown); extremely hard wood (too hard to carve even with a chain saw) Crownshaft: none Spread: 20'-30' Leaf Description: bipinnate (branching to two orders); flat; 25'-20' long and 10' wide; leaflets and secondary branches mildly pendant; leaflets are wide, fishtail shape and tend to spread out touching the leaflets on the adjacent branchlet; medium green Petiole/Leaf bases: 1'; unarmed; often covered with some black fiber; un-split Reproduction: monoeciuos Inflorescence: below the leaves; 10'-15' long; pendant with very thick, deep green peduncle and many short side branches; white flowers Fruit: light green turning to reddish when ripe; full of very irritating and toxic oxalates

Horticultural Characteristics Minimum Temp: 26F Drought Tolerance: moderate to low Dry Heat Tolerance: moderate Wind Tolerance: moderate to low Salt Tolerance: low Growth Rate: moderate Soil Preference: widely adaptable, but prefers slightly acidic soils Light Requirement: full sun Human Hazards: toxic fruits (oxalates) Disease or Horticultural Problems: very heavy branches need to be removed regularly; removal of dead trees extremely labor intensive; heavy feeder (needs a lot of fertilizer) Transplants?: poorly tolerant Indoor?: likely poor choice Availability: moderately rare (can sometime be acquired in standard nurseries)