Organic fertilizers! Also, spray the foliage with liquid seaweed at half the label strength. When you repot, incorporate pourous stones in the mix. Topdress the soil surface with more stones and/or plant mosses. Make sure the soil never dries out yet always has good drainage. Most tree ferns like cool nights and warm days, but never dry air.

I'll reemphasize the above post: good draining organic mix and organic fertilizers only! Your plant is a Cibotium species and hates inorganic fertilizers, unless applied at VERY low doses. These plants love moist well draining soils. Too bad you aren't in zone 10, you could try this one outside in a protected spot. PF

This species is said to be slow to form a trunk when kept in a container.

Dicksonias (and yours is of the same family) are slow to make a tall trunk anywhere! Think in terms of years and decades...'eventually'. My D. antarctica is just about to ten feet at the rate of six inches a year. (sigh)

In Hawaii, is it an understorey plant? If it is, then leaf mold and leaf litter will probably help to hold the water, like a sponge, in between 'official' waterings.

You've probably got Cibotium glaucum, sold in gift shops in Hawaii as potted up offsets rather than fully trunked plants. There are four 'pure' Cibotium species from Hawaii, plus a naturally occuring hybrid that kind of qualifies as an extra 'fifth species' in its own right. Occasionally Cibotium chamissoi too turns up in the trade, misnamed as 'C.splendens', but the others are more or less unobtainable. Cibotium are not 'Dicksonia', as an earlier poster claimed - although it's true that they belong to the Dicksoniaceae rather than the much more numerous Cyatheaceae - but occupy their own discrete genus with perhaps a dozen species recognized worldwide (Central America and S.E.Asia has the remainder).

Care for all of the commonly encountered types is similar. Very free drainage and an in indoor frost-free berth for the winter are obligatory - Perlite or orchid bark makes a good drainage additive to the potting compost which must be mixed differently from your standard moisture-retentive ferny compost. So, open out the structure, boost the drainage, and be careful with your watering regime. They are not easy ferns by any standards - waterlogging and fertiliser overdose are the common mistakes.

Steve - Brighton, Sussex Coast, UK

Having recently returned from Hawaii I found Cibotium chamissoi by far the most frequently grown native tree fern. It also seems to be the species available as trunk tip cuttings in a few locations. I brougt four home. The only Hawaiian cibotium I've been able to aquire in TX or CA is the glaucum. On the north shore of Kauai I found a few Sadleria. During 10 days of bushwhacking on Oahu & Kauai I did not find Angiopteris or Sphaeropteris cooperi established as an evasive species, though I've heard it is.
In Hawaii Walmart, Home Depot, and Lowes all sell Sphaeropteris cooperi and not the natives..- weird.

Phudnall,

These stores are allowed to sell C. cooperi in Hawaii! That is totally irresponsible of the government. Sometimes I can't imagine what people are thinking (maybe just $). The only time I saw C. chamissoi in the states was in LA. It is a beautiful tree, but forms so many pups. Did the ones in the wild have many (did this fern form clumps, or mostly single stems?). It's cool you got to see these in the wild. PF