Soft Tree Fern Overview
|Official Plant Name||Dicksonia Antartica|
|Common Name(s)||Soft Tree Fern, Australian Tree Fern|
|Foliage||Trunk-like rhizome, rosette of pinnately divided fronds on top|
|When To Sow||March, April, May|
Full Shade / Partial Shade
2.5 – 4M
2.5 – 4M
Moist but well drained
Neutral / Acidic
Tree ferns are an incredibly striking plant that look fantastic in a shaded garden environment.
Native to Australia and New Zealand, it is fairly popular in the UK because of its ability to survive in all but the coldest of UK garden landscapes.
The Dicksonia Antarctica (commonly known as a Soft Tree Fern) is probably the most popular type in the UK, because of its ability to survive colder winter conditions of up to -5°. Their favourite habitat is in the shade, preferably in humid conditions. Provided they have an ample water supply, they can also thrive in direct sunlight.
In the wild they rely on dead leaves falling from the canopy and providing a nutrient-rich soil that prevents the need for direct sunlight. As such these plants need nutrient-rich soil to grow in.
Their fronds (large divided leaves stemming from the top of the trunk) will generally reach between 5-7ft in length when fully matured. That being said, they grow at an incredibly slow pace, especially when they are not kept in their preferred conditions. Generally, you might expect their trunk to grow no more than 1 inch per year. Bear this in mind when choosing your plant, as it should already be at or near the height you’d like for your garden.
Very old plants in natural conditions have been known to grow up to 6 metres in height – and can sometimes topple over under their own weight. They will then simply re-root and grow again.
The plants are quite amazing for their ability to adapt to new environments. In fact, you could saw a matured tree fern in half at the trunk, plant the half with the crown in the ground and it would establish new roots and continue to thrive.
Fern Tree Types
There are four main types of tree fern common in the UK, each with varying resistance to frost:
- Dicksonia Antarctica (Soft Tree Fern)
- Dicksonia Fibrosa (Golden Tree Fern)
- Dicksonia Squarrosa (New Zealand Tree Fern)
- Spaeropteris cooperii (susceptible to frost – should always be kept in a pot and brought inside during Winter)
You should choose the right type of fern for your garden based on the hardiness of the plant and the conditions it’s likely to be living in.
Where & How To Plant Tree Ferns
The best time to plant tree ferns is in the Spring-time, as this is the plant’s favoured time of year.
These plants do not cope well in windy conditions, we would advise keeping them in sheltered conditions – preferably protected by a fence, wall or covering tree that will buffer any prevailing wind.
The top of the plant should have ample space to spread without crowding. The underside of large trees is often the perfect habitat for them to thrive. These plants are used to growing under tree canopies in forests and woodlands, so you should look to mirror this environment for them as best you can.
If you buy a container-based fern from your local garden centre, you should aim to plant it at the same level as it was in its container.
If you purchase a tree fern at a young age and it doesn’t currently have any fronds, you should aim to plant just enough of the trunk to keep the plant stable in its footing. At this stage, it’s important to continually water the young plant every day until you begin to see greenery.
Experts advise that you shouldn’t feed the plant during its first year in the ground, as starving it of an easy food source will encourage the plant to lay roots in the ground.
Tree Fern Care, Feeding & Watering
Tree ferns do not respond well to drying out, so it’s important for you to water them year-round. In particular, the driest and coldest months of winter and the warmest months of summer will require diligent watering. Be sure to spray the trunk and foliage with water to prevent the plant from drying out. The life of this plant is at the top of the trunk, meaning you should aim to feed from the top down.
With that being said, tree ferns are fairly low-maintenance and aside from regular watering, they won’t require too much attention through the year.
Growth of the plant usually takes place between April – August in the UK and this will be a key period during which you should be feeding the plant regularly. It’s recommended that you should apply liquid feed to the base, fronds and trunk of the plant at least once a month during this period.
Many gardeners like to trim the dead fronds that hang over the trunk, but these do provide added stability and help to keep moisture trapped in the roots and base of the stem.
If you would like to trim the brown dead fronds from the plant, you shouldn’t trim these any closer than 5 inches from the trunk, as the stem of the fronds help give stability to the trunk as it grows taller. While they can seem unsightly to some, they will help your plant to thrive in the long-run.
Generally, these plants are pest free, which should negate the need for any pesticides.
Protecting A Tree Fern During Winter
During the colder winter months, it is common for some fronds of the plant to be damaged by frost and/or wind. Sometimes with a mature plant, the entire set of fronds will be killed off.
Nevertheless, the fronds should grow back the following Spring, provided that the crown has been fully protected from the cold weather.
We would recommend starting to protect your plant before the coldest winter months set in – and definitely before the first frost of winter.
To protect the crown, you will need to use garden fleece (leaves, straw or shredded paper will also work) securely tied in place at the growing point of the fronds. This will insulate the head of the trunk (key for its survival) against cold, windy weather.
If the temperatures get really cold, we also recommend tying up the fronds, as this will better insulate the crown and better protect against windy conditions.
Add a few layers of leaf mound to the base of the plant to help protect against frost and provide additional nutrients.
Winter protection should be removed in March as the new foliage starts to emerge for Spring.
See the care tips at Burncoose Nurseries for a visual guide on how to wrap up your fern in winter.
How To Revive A Tree Fern
If your fern has lost all of its fronds, it might not necessarily have died. Sometimes a tree fern can shed all of its foliage during winter, though this is not normal as they tend to be evergreen plants. This would be considered a sign that the plant is struggling and may need further protection from the cold.
You should carefully inspect the crown of the plant during the following spring when you would expect new growths to appear. You would generally expect new fronds to begin to emerge within one month of spring as confirmation that it is still alive. These will look like small bumps covered in brown ‘hair’ at the crown. If you see these, your plant is still alive and kicking.
If there is still no growth, check the roots. Are they rotten, dry or brittle? If so, it’s likely that the plant has died. Unfortunately, this means the plant is past saving.
If the roots are still alive but there are no fronds emerging, it might just be that the plant needs some TLC. Water the plant regularly with diluted fertiliser and place mulch around the base of the plant to preserve moisture. Try and keep the plant in warm, shaded areas to promote fresh frond growth.
I'm an avid gardener and home DIY enthusiast from Yorkshire in the North of England. I'm passionate about helping our readers get out into their gardens - by making the most of the outdoors and ensuring they get the best possible deals on their gardening equipment. I also believe strongly in the preservation of our beautiful garden wildlife.