Lacy Tree Fern (Cyathea Cooperi)

I think this is probably one of the most beautiful tree ferns one can grow – the huge, lacy leaves, and delicate golden hairs on the stems and trunk, plus the satisfying rate of growth makes this a worthwhile tree-fern to add to your collection if you have the space!

Cyathea cooperi, also known as the Australian tree-fern is a tree-fern native to Australia, in New South Wales and Queensland. It can also be called lacy tree-fern, scaly tree-fern, or Cooper’s tree fern. Not to be mistaken for Cyathea australis!

The name comes from Cyathea – from the Greek ‘kyatheion’ meaning little cup, referring to the structure that holds the spores, and Cooperi – named in honour of Sir Daniel Cooper.

It’s a fast growing tree-fern ( unlike Dicksonia Antarctica, the one commonly grown in the UK), and can grow up to a foot a year in ideal conditions, though in the UK I find it only grows about 6 inches a year as the growing season is shorter. It can be invasive in warmer locations – they are becoming a pest in Hawaii. It naturally grows in tropical, tropical lowland, and montane locations, most commonly next to streams, and in gullies where water is abundant, and winds are lower.

The ‘wild height’ of the fern is up to 15 meters, with a 30cm thick trunk, but you can stunt it by keeping it in a tightly restrained container. It’s a semi-hardy tree-fern, and can really only stand temps down to about 0 centigrade, and does need to be brought into a warmer winter location. If put in a cold greenhouse (no freezing) it will stop growing for the winter, and start again in spring, but if brought into the house it does continue to grow slowly year round.

Some people in the US have found its more tolerant of cold, and if it frosts lightly it will lose its leaves, and then re-grow later. As will all plants, the more mature it is the hardier it is. I find with me ( I bring mine into the house!) it tends to lose its shorter, more robust summer leaves, and send up darker green, larger, and more delicate leaves for the winter.

Tree ferns need to have their trunk and crown wet at all times. The trunk is really only a modified root, and the growth is only from the top of the plant so if the crown dries out the fern will die! I give mine ( its got a 3 foot trunk) about 5 litres of water a day, and it sucks it all up easily.

Please note: unlike Dicksonia Antarctica, this tree fern cannot be bought as a trunk without soil – it won’t make it through the transplant. It need to be bought as a plant in a pot, but as it grows so fast it’s not a problem to wait a year or so for a substantial plant.

I have noticed they can be bought in the UK from the Gardeners club, and already are trunk forming and looking great.

The growth conditions for this tree-fern are pretty much the same as all tree ferns, though this one is particularly easy to grow if you follow the basic guide below:

• Shade through to semi-shade. It can go in full sun, but needs a huge amount of water to keep it alive.

• Temperatures: 30 degrees to about 0.  I bring mine out after all frost danger has passed, and bring it in before any chance of frost

• No tree ferns like very windy locations – I think this is due to the drying out factor. • Lots of water, very damp soil, and keep the trunk and crown damp. Do not leave sitting in water though!

• Soil: Humus-rich, neutral to acid soil.

 • Feed: a seaweed feed, or tomato feed at a ¼ dilution is best – anything stronger will burn it. I tend to do it less with re-potted ones, and more for pot bound ones.

• Re-pot when the plant outgrown its pot – the roots will pop out the bottom, and you can tell that the soil is full of roots if you stick your finger into it. If you want to control its growth and not re-pot, it’s important to give it some mild fertilizer about once a month.

Get some ferns here!