Polystichum Proliferum - A Stumpy Tree Fern

Not quite a tree fern, more of a stump fern :) This guy grows under the feet of Australian tree ferns and will eventually grow a short dark brown stump, from which will emerge loads and loads of very dark green, stiff fronds.

The interesting thing about this guy is that if you pin one or more of the leaves to the ground a baby one will grow from the tip. This means that you can fairly quickly cover ground with these guys. Keep the frond(s) pinned down until the baby takes root.

They should be grown in damp shaded areas. They are 100% imprevious to anything the Winter will throw at them. Their fronds last all year round and throughout the Summer it will grace you with 20 or 30 new fronds. I really love this fern. It ticks all the boxes and should be in everyone's garden.

Cyathea Australis

Imagine the trunk of a Dicksonia combined with the fronds of a Cyathea. This pretty much sums up the Cyathea Australis. It is a curious fern with its main identifying feature being the slimness of the frond stems. Loads of these spring out from the centre of the trunk in all directions during the Summer. The fronds do tend to dry up easily around the edges though for some reason no matter where I try and place them. Not sure why yet?

This fern is supposed to be Winter hardy to -7c. I have not tested this yet, though I know they do remain undamaged at -4c. Some suppliers (usually online ones) tend to sell these as severed trunks. Try to avoid these as they will last that year and not recover for the next year. This applies to all Cyatheas and some Dicksonia species. Also, some Cyathea require the nutrients stored within exiting fronds to create new fronds.

Again frondless Cyathea will usually struggle to survive kicking out one or two fronds in the first year and then perishing due to starvation. Fortnately C. Australis doesn’t mind being frondless. However watch you don’t get conned !!!

Cyathea Cooperi

This is a fast growing tree fern which forms a slim trunk covered in white hairs. It produces large fronds which are shaped like huge paddles. It looks very attractive sticking out of an area planted with ground ferns. It can take some good sun, and it appears to prefer it like this. Too much damp seems to rot it’s new fronds before they have a chance to unfurl.

Like Dicksonia Squarrosa the Cooperi tends to sprout new shoots from its base (roots around the base). I have seen snails attack these so watch out!!!

The only real downer of Cooperi is that it really hates the Winter. -2c will damage the fronds, browning them off on their tops. Not much more than this will kill it altogether (-5c). You should really take it into shelter for the Winter, such as a greenhouse, and heat it or cover it with fleece. I have found that the fleece can rot away the white hairs covering its trunk, but it doesn’t seem to mind this.

Cooperi is a difficult fern to get right. It doesn’t like the cold, it doesn’t like too much damp and it dries out fast in the sun. It is really one for a specialist collector.

Dicksonia Fibrosa

This tree fern is becoming more common. It has a darker, more fibrous trunk which is kind of squashy when pressed. The fronds are shorter and darker in colour than Antarctica. The fronds don’t break as easy either. However, they are slower growing, fronding only once or twice a year and not loads of fronds like Antartica either.

A real positive point is that they are far more hardier to the Winter elements than Antarctica. I have had a few of these sitting in -10c without any frond damage whatsoever. Like Antarctica they are shipped around as bare trunks, but they are a little more stressed like this and may not revive, so try and get a rooted one if you can.
Again, they look nice in groups, but big ones are hard to find these days and are pretty expensive. Some places sell Fibrosa as Antarctica, so keep a look out as you may get yourself a bargain... the biggest sign being the squashy trunk :D

Dicksonia Antarctica

Common tree fern which comes in a whole variety of sizes. These are so common because they can just walk into the forests of Australia and hack them down into the sizes they want to ship. Mostly found with no roots or fronds. If you are selecting one you really want one with fronds that are just beginning to show rather than established fronds shooting out all over the place. You should also splash out and get a big one as these guys are very very slow to produce trunk height.

The foliage will die back when Winter arrives, though with each year of exposure they seem to adjust and keep their foliage for longer. All you need for Winter protection is a fat fist full of straw stuffed into the crown to protect the late Summer fronds from being beaten up by frost. You can also tie a fleece around the trunk if you wish, but this is only necessary if you live in very cold areas (regular -10c).

With these (and all tree ferns) you need to keep them moist to get the best out of them. These like to be sprayed on the crown and foliage. If you do this religiously then you will be rewarded with huge fronds. They are pretty wind resistant too, but make sure the whole thing doesn’t fall down and crush something if you are placing it in a windy spot.

When digging a tall one in jam bricks around the whole you are putting it into. This will help keep moisture around its base and also add stability until it managed to re-root itself.

Dicksonia Antarctica look very nice in groups of 3, placed close together in a triangle with different heights. If you can afford it try and place them like this to get the best visual effect. Partially bury rocks around them to encourage moss to grow around their bases to give them that authentic forest look. A couple of ground ferns to finish the look off. Very nice :)

Cyathea Medullaris - A Black Beauty.

In my personal opinion this is the best of all tree ferns. It can take full sun right from being a baby and has the most beautiful soft fronds.

I have read that this fern is a real slow grower. With experimentation I have found that it will grow very quickly if you give it good light and mist and water it every other day. Like all Cyatheas you don't want to drown the crown of the trunk, more give the whole trunk a good soaking. It also likes to be pot-bound which I find really weird.

The fronds on this guy are absolutely huge. Even before they start trunking you can get 3 foot fronds out of them. They are a fresh light green with a black rib running down their middle. Once it trunks the contrast of the green fronds with the black trunk is mesmerising.

When the dreaded Winter appears I move mine into an unheated greenhouse and leave them be. My greenhouse has been as low as -4 inside and this guy has not been bothered by it. However, when the next Spring arrives the old fronds do look rather tatty. It must be said that with this (and all Cyatheas) you must not cut the tatty fronds off until they go totally brown. Cyatheas draw nutrients from old fronds to create new ones (kind of like palms). Cutting off the tatty fronds deprives them of their nutrient stores and the plant will start to decline!!! Cyathea Medullaris are hard to find, but it is really worth the effort.

Dicksonia Squarrosa

This is a rather curious tree fern which has an ability to spawn offshoots from its roots, base and trunk sides. It is rather frost tender at the very top of the trunk however so watch out. I originally came across this one in a garden centre which was selling it as a Dicksonia Antartica, even though the two look totally different. That Winter (2003/2004 I think Manchester suffered heavy frosts at -10c for many successive nights). This obliterated it even with the rather weak straw protection I had piled onto it.

The following year new fronds did not appear from the top, rather the roots and lower side of the trunk. It later died due to being fried by the 30c sun of the following Summer. It is now a rotting stump despite my best efforts to revive it :(

So, with these findings in mind the next one i bought i monitored rather more carefully. I have discovered the following:

• It needs constant moisture. Do not place this guy in a sunny spot. It will quickly dehydrate and brown off the leaves. Spray it with your hose at least 3 or 4 times a week in the Summer... foliage and trunk(s) !!!


• The fronds and the top growing point of the trunk will die off at -4c if wet. Offshoots will die off completely at -4c tops. The roots will be tough enough to survive much lower temperatures than this but the main growing area of the trunk will die.

You really need to bring this one into a damp area away from frost in the Winter (unheated greenhouse is OK with some fleece over it). They are pretty fast growers, and the fact they readily produce offsets is a bonus, so if you are willing to look after them properly then go get one !!!

Tree Fern tests in Winter 2006

During Winter 2006 I selected the following ferns for frond damage testing:

• Dicksonia Antarctica – Outside with straw stuffed on the crown.
• Dicksonia Fibrosa - Outside with straw stuffed on the crown.
• Dicksonia Squarrosa – Unheated greenhouse with no protection.
• Cyathea Cooperi - Unheated greenhouse with no protection.
• Cyathea Medullaris - Unheated greenhouse with no protection.
• Cyathea Australis - Unheated greenhouse with no protection.
  

That Winter had a max outside of -8c and inside greenhouse temp of -4c. Here is what happened:

• Dicksonia Antarctica – Unrooted specimens lost their fronds at -7c. Rooted specimens had some damage but no loss.
• Dicksonia Fibrosa – No damage to fronds at all !!!
• Dicksonia Squarrosa – Upper fronds browned off and lower fronds were OK.
• Cyathea Cooperi – All fronds browned off.
• Cyathea Medullaris – No damage to any fronds.
• Cyathea Australis – No damage to any fronds.

D. Fibrosa therefore won out with no damage to the fronds at all !!!! I was surprised by this. I was also surprises that the C. Medullaris had no frond damage at -4c. It is supposed to be a weakling, like the C. Cooperi.