There are many types of tree fern, but the most common one in the UK is Dicksonia Antarctica.
Others considered OK to grow in the UK outdoors are Dicksonia Fibrosa, and Cyathea Australis.
As the name Dicksonia Antarctica suggests, this tree fern grows in colder conditions, and can tolerate temps of -10 for a short time. It is advisable to wrap the trunk and the crown in fleece, or to create a cage of chicken wire and stuff it with leaves. If the crown dies / dries out, the whole plant is dead!
The Lost Gardens of Heligan have huge specimens growing in their jungle valley that were abandoned for over 50 years, and are still growing fine, without any protection at all.
Image 1) the oldest tree ferns in the Lost Gardens of Heligan, considered to be over 200 years old
Image 2) the graceful beauty of the unfolding crosiers on a young tree fern
Image 3) though not a true tree-fern as it does not form a substantial trunk, Blechnum Chilense grows to approx. 5 foot tall, is totally hardy in the UK, and has much of the grace and delicacy of a true tree-fern. It also spreads easily forming a fern grove rather quickly.
Care and requirements:
- Requires humus-rich, neutral to slightly acid soil.
- Not so wind tolerant as these are undergrowth plants, and not very salt tolerant.
- Watering: must be kept damp at all times. This is critical. Tree ferns will die if the whole plant, especially the trunk is not kept damp. I water mine on a daily basis, watering the crown, trunk and soil. This said, they do not like to sit in water, so make sure you have well-drained soil.
- Considered to be semi-hardy / hardy, depending on the type. I always wrap mine for the winter, and have not suffered a loss yet.
You can get one here: