Personally, I just use a general-purpose balanced fertilizer, but don't fertilize very often. Fertilization doesn't generally seem to be a big issue with ferns for whatever reason; I take it as proof of superiority to those heavy-feeding flowering plants, though. :)

Patrick Alexander

commercial grower here using Peters 24-8-16
seems to give best results, tho your climate and water supply will factor in.

Just the same, I only feed every other watering at 100ppm or less... which is about a 1/4 of what most flowering plants would use.

not familiar with Peters forula, i guess we dont get it here in the UK.
I like the NPK makeup tho!

Oh I would just love a tree fern, they are cool plants!

Stephen, do you manage to gropw one in your garden in Brighton? Thyre from New Zealand arent they?

ohhh forgot to mention, thats liquid fertilizer for the tropicals.

hardy ferns get a small top dressing of Osmocote 18-6-12 after last frost.

have you noticed the 3-1-2 ratio? works well.

I also double what mr pope said about organics, maxicrop kelp is especially nice. Wish I could go strictly organic with my fertilization but it is simply not possible economically.

drew

Do I manage to grow a tree fern in Brighton? I'm well over the 100-species barrier for tree ferns now - too many to make an accurate count! Some indoors, some outside in the courtyards, and many more rarities contained in a big glasshouse tree fernery complex. Virtually all self-propagated from spore, hardly any shop-bought. That's my governing principle - if I can't raise it from scratch myself, I can't have it. I don't feel comfortable about forested ferns being imported from the southern hemisphere.

Yes, New Zealand DOES have the most fantastic tree fern habitats on both of its big islands, yet in terms of sheer species diversity it's a relatively poor region and can boast only four Cyathea species and three Dicksonia varieties. Neighbouring Australia has many more tree fern species than that - the Queensland rainforests are especially rich. The greatest concentration of tree fern species are found in the tropical forests of south-east Asia - especially Malaysia and Indonesia. Central and South America is the next richest region, brilliantly documented in the botanical literature of the 1970s by your famous Harvard fern professor Rolla Tryon. Much of what we now know about tree ferns comes from him.

No agreed count exists as to how many tree fern species there might actually be out there, but it could be something on the way to maybe one thousand. A few species fall into the 'extinct' category every decade, balanced by the discovery of brand new species - the high-elevation cloud forests of Papua New Guinea are still a pristine treasure trove of undiscovered tree fern varieties. Having said that, the medium-term outlook for the planet's surviving tropical rainforest and cloudforest habitats - let alone tree ferns - is bleak.

And the garden trade in the US has tapped into perhaps four or five tree fern species. Just the tip of the iceberg...!

Steve - Brighton, Sussex Coast, UK

Interesting stuff Stephen, I admire your principles as regards growing your own rather than importing them-
I feel the same about cacti, they are becoming increasingly rare now due to over collecting
(Golden Barrel is a prime example, they are very common in the UK which gives a false image as to their numbers-
they are actually endangered now!)

Thats interesting about Australia having more species than NZ, I am quite surprised as I always imagine
NZ to be pristine cloud forest territory unlike our preconceived idea of Australia!

Yes, 'pristine' NZ is in better shape, ecologically-speaking, than the more aggressively developed Australia. Even so, NZ is a bit marooned in terms of tree fern diversity - more to do with its geological age and land-mass isolation than with attitudes towards conservation. Plus, NZ latitudes don't really permit enough wet sub-tropical habitat - the greatest TF species-richness always coincides with wet tropical habitats. Hence Malesia and Central/South America as the true tree fern epicentres. Literally HUNDREDS of TF species there...!

Isn't the climate in NZ much wetter than Oz tho?
I always think of NZ's climate as being like that of Britain.

But Australia has true tropical rainforests - where the greatest TF diversity always occurs - but NZ doesn't.

Interesting! I guess we get too much info from our TVs!
Austrailia is a desert, warm beaches, and NZ is a gren oasis, thats the image our TV gives us!