What temps can Dicksonia antarctica take , lowest temps to start protecting?

Post Reply
Rachelpalm

What temps can Dicksonia antarctica take , lowest temps to start protecting?

Post by Rachelpalm »

Hello
bought my first Dicksonia antarctica this year which is in a pot. When should I start protecting it? Night temps at the moment are no lower than about 7c . I was hoping I could start protecting it start of Nov. What is the lowest temp they can take without protection? When will you start protecting yours?

Thanks
pdid

Re: What temps can Dicksonia antarctica take , lowest temps to start protectin

Post by pdid »

I`ve had mine for a few years now. I generally wait till frost is forecast then stuff the crown with straw, tie the fronds up and move next to the house wall. If it looks like we`re going to get an extended period of really low temps then I would bring inside.

I`m into new territory this year however as mine are now planted out.
User avatar
Dave Brown
Site Admin
Posts: 19742
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Re: What temps can Dicksonia antarctica take , lowest temps to start protectin

Post by Dave Brown »

I generally have not protected other than a ball of fleece, or leaves stuffed in the crown. The fleece worked better than leaves due to Blackbirds pecking the leaves out and the knuckles getting frosted :roll:

Last winter my Dicksonia antarctica were unwittingly protected by 33cm of snow pinning the fronds down and creating an igloo with warm ground air keeping the plant snug. Even after the freeze which saw -10C here I still had a full crown of fronds icon_thumright After that I protected by throwing a duvet over the crowns trapping warm ground air under.

I will not be gathering fronds up and wrapping, as this allows all that ground warmth to radiate into open space while allowing the Dicksonia antarctica to gradually cool down to air temps. I am sure the fleece/duvet over will protect from freezes better than wrapping. :wink:

Dicksonia antarctica do not seem to suffer frond damage at above -5C but below that they will fry. The advantage of keeping fronds is you get a much better flush, as the plant is photosynthesising to help produce the new flush :wink:
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk
User avatar
Adam D
Posts: 3574
Joined: Tue Jul 14, 2009 10:47 pm
Location: Scotland

Re: What temps can Dicksonia antarctica take , lowest temps to start protectin

Post by Adam D »

In my experience they will survive a normal dip to -8C and bounce back to above freezing during the day.

They don't like -14C, -17C and -18C.

The threshold for death is somewhere in between.
sanatic1234

Re: What temps can Dicksonia antarctica take , lowest temps to start protectin

Post by sanatic1234 »

I have read on a website that only deals with ferns/tree ferns and it said on there that a Dicksonia antarctica's max hardiness level was -9c.
User avatar
Yorkshire Kris
Posts: 10163
Joined: Wed Dec 16, 2009 8:59 am
Location: Rural South Wakefield, Yorkshire Lat 53.64 Long-1.54

Re: What temps can Dicksonia antarctica take , lowest temps to start protectin

Post by Yorkshire Kris »

Mine died at -8- -10 over the last two winter. Only protected with straw in the crown. As been said many times this year. It was the duration of the cold that killed them not the lowest temps.
Tom2006
Posts: 8094
Joined: Thu Sep 30, 2010 11:23 am
Location: East Yorkshire UK

Re: What temps can Dicksonia antarctica take , lowest temps to start protectin

Post by Tom2006 »

Daves advice is good but bare in mind he didn't have to continual day and night zero or subzero temps. As others said its the continual freezing temps that kill them. In a normal winter in your location a dry thick packing of fleece in the crown should be fine. As soon as temps get below -6c you need to give much more protection from a duvet to the thick loft type insulation but always remove once temps rise above freezing.
Most wanted list - Any Young Trachycarpus and/or fern.
cordyman

Re: What temps can Dicksonia antarctica take , lowest temps to start protectin

Post by cordyman »

Tom2006 wrote:Daves advice is good but bare in mind he didn't have to continual day and night zero or subzero temps. As others said its the continual freezing temps that kill them. In a normal winter in your location a dry thick packing of fleece in the crown should be fine. As soon as temps get below -6c you need to give much more protection from a duvet to the thick loft type insulation but always remove once temps rise above freezing.

if we get any serious long low temps I have a boiler jacket in the shed ready to wrap up
Tom2006
Posts: 8094
Joined: Thu Sep 30, 2010 11:23 am
Location: East Yorkshire UK

Re: What temps can Dicksonia antarctica take , lowest temps

Post by Tom2006 »

Good plan BUT bare in mind without any heat source in deep prolonged cold they will still freeze. Maybe a few hot water bottles under the jacket IF we get a repeat of last winters spell, just change the water every 12 hours or so.
Most wanted list - Any Young Trachycarpus and/or fern.
cordyman

Re: What temps can Dicksonia antarctica take , lowest temps

Post by cordyman »

Tom2006 wrote:Good plan BUT bare in mind without any heat source in deep prolonged cold they will still freeze. Maybe a few hot water bottles under the jacket IF we get a repeat of last winters spell, just change the water every 12 hours or so.
Tom is it just the crown I need to protect or the roots with water bottles too?
User avatar
Dave Brown
Site Admin
Posts: 19742
Joined: Sun Jul 09, 2006 10:17 am
Location: Chalk, (Thames Estuary) Kent, England 51.5N 0.3E
Contact:

Re: What temps can Dicksonia antarctica take , lowest temps

Post by Dave Brown »

If you gather fronds up and wrap, then you have no external warmth, and are exposing the ground/roots to radiation frost.

Throwing insulation over the top allows the ground warmth to continually rise into the protected area, and at the same time is protecting the roots from any freeze. :wink:
Best regards
Dave
icon_thumright
_________________________________________________
Roll on summer.....
http://www.hardytropicals.co.uk
Tom2006
Posts: 8094
Joined: Thu Sep 30, 2010 11:23 am
Location: East Yorkshire UK

Re: What temps can Dicksonia antarctica take , lowest temps

Post by Tom2006 »

No harm in trying to warm the roots if its potted although I believe that if the roots were to die but the trunk and crown survived then the roots would re grow but I don't know this for certain.

To be honest, if your Dicksonia antarctica is potted then just bring into a shed or garage if deep cold is forecast.
Most wanted list - Any Young Trachycarpus and/or fern.
Simba

Re: What temps can Dicksonia antarctica take , lowest temps

Post by Simba »

Dave Brown wrote:Throwing insulation over the top allows the ground warmth to continually rise into the protected area, and at the same time is protecting the roots from any freeze. :wink:
I can appreciate how that could work on a 2 or 3ft trunked specimen, but what about if the tunks is 6ft or more....?
Tom2006
Posts: 8094
Joined: Thu Sep 30, 2010 11:23 am
Location: East Yorkshire UK

Re: What temps can Dicksonia antarctica take , lowest temps

Post by Tom2006 »

Simba wrote:
Dave Brown wrote:Throwing insulation over the top allows the ground warmth to continually rise into the protected area, and at the same time is protecting the roots from any freeze. :wink:
I can appreciate how that could work on a 2 or 3ft trunked specimen, but what about if the tunks is 6ft or more....?
You would need a very large cover so it wouldn't work. Don't forget that Dave's winters although they have been cold often saw the daytime temps go above freezing. If you get day and night time temps at or below freezing for a while you need some serious protection on them as they will eventually freeze right through.

At the moment I'm using fleece in and around the crowns of mine and all seem to be ok so far although the coldest we've had is -2-3C and we haven't had an ice day yet, and hopefully wont all winter although this weekend will push us close.

I think the best bet for the larger tree ferns is the large hot water cylinder insulating jackets, on a larger fern get a couple and then stuff the crown with LOADS of fleece and cover so stop rain/snow melt.

I am unwrapping my fleece during the day IF its got wet, drying the fleece and back on. If it looks to turn VERY cold they will be either in my heated polyhouse or in the living room! :lol:
Most wanted list - Any Young Trachycarpus and/or fern.
Post Reply