Monty Don's foolproof tip will protect these tropical plants over winter

Celebrated gardener, TV presenter and author Monty Don warns that if you’re fortunate enough to have a stunning Australian tree fern Dicksonia in your backyard, you may need to take steps to protect it when temperatures start to drop. 

'The tree fern, Dicksonia, is not reliably hardy although it is quite happy down to about 23˚F (-5˚C),' he says.

So what does Monty suggest you do to ensure these tropical plants survive the winter cold?

Monty Don's tip for protecting tender tree ferns in winter

On his website, Monty Don says that when it comes to tree ferns, there are two possible methods for protecting plants from frost or more more severe winter weather. 

1. Dig them up and store them somewhere warmer

Monty says that if the forecast is for super-freezing weather – and you have the space for storage – you can dig up your tree ferns and keep them in pots in a frost-free place such as a greenhouse until warmer weather comes back in springtime. 

'They have minimal roots in the ground,' he points out. 'However, there is no need to bring them in under winter cover if you protect them where they need protecting most.'

2. Protect the stem of your tree fern

When it comes to potential damage from frost, it’s not really the roots you have to worry about with the Australian tree fern, which makes an excellent stand-out specimen in any landscaping ideas featuring trees. 

'The secret is to make sure that the central soft inverted cone at the top of the stem – it is not really a trunk as it is made up of rods of root – is unable to fill with water that can then freeze,' he says. 

Monty advises that the easiest way to protect the top of the stem is to pack it with straw which both insulates and acts as a sponge. 

'I change this straw once or even twice during the winter,' he says. 'Then I bandage a thick layer of [horticultural] fleece around the vulnerable top six to nine inches of the stem to provide extra insulation.'

Horticultural fleece is ready available online at Amazon. Look out for products like this Abimars frost protection fabric (from Amazon), which can be cut down to the size you need.

Jeremy Yamaguchi, CEO of garden care company Lawn Love suggests you can also add a layer of bubble cushioning wrap (available on Amazon) over the fleece. 

'This will keep the moisture inside so the trunk doesn't dry out and the leaves stay protected,' he says. 'If it gets colder than 14˚F (-10˚C) in your area, use more layers of cloth or even a heating cable to warm your precious tree fern during the colder nights.'

But don’t worry too much about the leaves, Monty adds: 'They will die back anyway so need no care, and the lower part of the trunk is not the crucial growing point, so this can remain unprotected too.'

Will you be adding this to your list of winter jobs in the garden this weekend?