Dahlia imperialis overwintering decision

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Somerset77

Dahlia imperialis overwintering decision

Post by Somerset77 »

Has anyone had any experience with these? This is my first winter with it and was wondering can it be left in the ground with heavy mulch or is it best lifted and potted in greenhouse?

My garden is located approx 1 mile from the sea (north Somerset) if this helps?

Thanks icon_thumleft
kata

Re: Dahlia imperialis overwintering decision

Post by kata »

'Montbeliardii' Don (GW) took his out.

Your best off looking at vid here

http://www.bbc.co.uk/programmes/b01nrcvs

For Dahlias


A tray -> newspaper -> gentle sprays of water->then store but watch for any rot, he waters when alsmost dry.

icon_cheers watch it.

:mrgreen:
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Dave Brown
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Re: Dahlia imperialis overwintering decision

Post by Dave Brown »

Dahlia imperialis isn't going to fit into a tray Kata :lol: We're not talking standard Dahlia here.

It depends on what you are growing them for Ss77. If you want just big plants (7/8ft tall) then you can leave them out with a good mulch. However if you want flowers, then they need an early start.

Mine flowered in December last year from a Feb sowing, but it was a frost free autumn. In general they would be frosted before reaching a flowering, size, however, if retarted under glass in March/April will give you flowers in July/August.

Kevin Scales on fb cut his back to about 5ft then lifts before the frost, but it is a huge soilball and very heavy by the looks of it. He keeps tubbed over winter then plants out again after the last frost. :wink:
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Dave
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Somerset77

Re: Dahlia imperialis overwintering decision

Post by Somerset77 »

Thanks dave, I was hoping you would say leave and mulch as space is a premium (I'm already using bedroom, spare room and kitchen! icon_thumleft ).

Will do what you suggest and dig up and start in GH in march :D
kata

Re: Dahlia imperialis overwintering decision

Post by kata »

Dahlia imperialis isn't going to fit into a tray Kata
Don't lol at me DB

Okdokay, just watched it again...

Cut down, lifted, and brought in. Also you need a good 'HOT' summer for them to flower...'Montbeliardii' says.

icon_cheers :mrgreen:
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Yorkshire Kris
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Re: Dahlia imperialis overwintering decision

Post by Yorkshire Kris »

kata wrote:
Dahlia imperialis isn't going to fit into a tray Kata
Don't lol at me DB

Okdokay, just watched it again...

Cut down, lifted, and brought in. Also you need a good 'HOT' summer for them to flower...'Montbeliardii' says.

icon_cheers :mrgreen:

I was pleasantly surprised when 'Montbeliardii'_ showed off his Tree Dahlias.
Ian Cooke

Re: Dahlia imperialis overwintering decision

Post by Ian Cooke »

I had one left in the ground in a sheltered spot in my Midlands garden for several years. It never flowered but made good foliage. Harsh winter a couple of years ago finished it.

Incidentally I saw this in San Francisco Botanic Garden a few weeks ago - flowering like crazy - huge clump probably 2-3m high and across. It didn't look quite like D. imperialis foliage and seemed too tall for D. merckii or D. sherfii and beyond that I'm lost on pink species dahlias. Any ideas anyone?
Dahlia sp (2)-qpr.jpg
kata

Re: Dahlia imperialis overwintering decision

Post by kata »

They're lovely Ian but need the heat and sun, probably why yours died,

He did allow his to get frost hit before he cut it down.

icon_cheers
Springy

Re: Dahlia imperialis overwintering decision

Post by Springy »

Ian Cooke wrote:I had one left in the ground in a sheltered spot in my Midlands garden for several years. It never flowered but made good foliage. Harsh winter a couple of years ago finished it.

Incidentally I saw this in San Francisco Botanic Garden a few weeks ago - flowering like crazy - huge clump probably 2-3m high and across. It didn't look quite like D. imperialis foliage and seemed too tall for D. merckii or D. sherfii and beyond that I'm lost on pink species dahlias. Any ideas anyone?
Dahlia sp (2)-qpr.jpg
Possibly DALIA TENUICAULIS?

I am growing 2 plants both named as dahlia imperialis and they both look totally different. One is multi-stemmed, grows to about 2-3 meters tall and has pink, single and double flowers with yellow centres on the same plant.
The other one has a single more woody stem that sometimes branches. This hasn't flowered for me yet though.

The pink flowering dahlia stays in the ground with a straw mulch and a bit of fleece. The other dahlia will be dug up and potted and kept in our outhouse.
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Dave Brown
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Re: Dahlia imperialis overwintering decision

Post by Dave Brown »

Here is a topic on Dahlia tenuicaulis :wink:

Dahlia imperialis comes from high altitude Central andSouth America. http://en.wikipedia.org/wiki/Dahlia_imperialis. It's leaves won't survive frost, but the stems are ok to maybe -2 or -3C, and the tubers to -6C if mulched. The advantage of their high altitude origin is that it loves our cool summers and is more than happy with the deluge we've had this year. Mine this year has really done well, although no flowers yet, and is currently around 3.5m (12ft)

Sorry, not a good picture as was taken at dusk, and is not easy to get far enough away to get a decent shot/
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2012-11-03-17-18-26 Dahlia imperialis .jpg
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