Protecting Dicksonia antarctica Treeferns in this freeze

[Dave Brown]

We may have another couple of days of very cold wather to come yet, and I heard that some of you have not protected your Dicksonia antarctica. Mine are not yet but the temps have not been as cold here although a biting NE wind.

The thing to remember about Dicksonia antarctica is that there is a rhizome that runs up the centre of the trunk protected by the roots and fibre that make up the trunk you see. The important thing is to stop the rhizome from freezing. They can take -10C in their native habitat, but that does not include several day freezes.

If your Dicksonia antarctica gets the sun during the day it will be warmed up ready to fight another cold night, but if it is in the shade the subzero temps become accumalative, gradually cooling it down to the point of freezing the rhizome. If the rhizome does freeze you get the dreaded orange goo later when it thaws out.

If your Dicksonia antarctica is in the shade you can throw a duvet over if is is small enough but needs to be almost touching the ground. If too tall, then also wrap the trunk to stop further cooling. If you suspect it is already cold, you could heat a towel and wrap with that to add a bit of warmth. As always protect the centre of the crown to stop damage to any knuckles (this year's growth).

In general Dicksonia antarctica fronds are hardy to around -5C and the plants to a short period of -10C.

If you want to keep fronds through a freeze throw something over the top, weighing them down, making an igloo that protects the trunk, rather than tying them up exposing the trunk. Also remember that the ground is a huge winter heat source, and as soon as you remove radiation frost and freezing wind from the equation, the soil surface temp rises to several degrees above freezing. The temperature at a depth of 1m is about 7 to 10C over most of the country.

Good Luck

[shanks]

hi dave
yep! the orange goo.......know it well, mine went like that, had it wrapped but must have been some showing at bottom, always good advice from though, loved the vid BTW on removing the mer

[pdid]

Thanks for this Dave.

I currently have a fleece bag stuffed in the crown, the trunk wrapped in a few layers of thinner fleece and then a large fleece bag over the top stretched over 4 bamboo canes around the plant which should hopefully trap any warmth from the soil weighed down with a few bricks. Hopefully this will suffice.

[sanatic1234]

My trunks are wrapped half way down Dave with 2 layers and have big fleece balls inside the crowns. One gets sun from 10am on wards and the other from 12pm on wards till the sun goes down. One of them the one that gets sun from 12pm on wards has the 30ft high conifers about 15ft away from it.

EDIT: I felt the section of the trunks that are not protected and they was warm on both tree ferns. So i am feeling happier now. Nice one dave for the input. I did even think about wrapping an old rug round the trunks.

[outatime1978]

all i have done is put golfing brolly's over the top like a canopy, a bit likes daves over his washingtonia and stuffed plant fleece in the crowns hope that may help!.

[The Codfather]

mumfie style for me.....

[Tom2006]

Great advice Dave. My four are snug in my heated Poly house.

[Bob]

Fallen leaves and old fronds stuffed in the crown of mine. Hopefully it should be enough.

[sanatic1234]

Well that is the trunks fully wrapped in fleece now. I will water the crowns when the weather permits as i certainly can't water the trunks now.

[davidjonesUK]

haven't had to protect mine at all this year still all green fronded little burnt on the tips but im happy the fact the crown is ready to burst just hope now the weather warms up, which it does show more mild weather from the SW.

[sanatic1234]

yeah the west is going to get milder weather david, jammy sod. My fronds are still nice and green on both, but just don't want to risk the new fronds getting damaged. I have a -6c to come on monday yet as well.

[karl66]

The fronds on my 5ft trunk are totally burnt to a crisp, the crown and the trunk are all wrapped & i have a large duvet on the top. karl.

[Tom2006]

I'd be tempted to move it into a shed/garage Karl as the roots won't have done anything.

[cordyman]

if you have a Dicksonia antarctica like mine which was well rooted in a pot when you bought it, these roots will uptake water for the Dicksonia antarctica, so i'd say best to leave in situ and protect. I'd only consider removing if you can't adequately protect the whole trunk and it has no roots, ie. just a log sat on soil

[sanatic1234]

I don't even think mine will be rooted yet, as i only planted it mid april last year. 1-2 years to root. But i really don't want to take the risk of digging mine up just incase it has started? If weather gets any worse then it will be getting lifted and put in my shed.