Early review of affects of the cold snap

[Paul in Essex]

I am massively shocked to find most of my Agave montana have been damaged. They will grow out of it, the centres are still strong, but I really didn't expect that. Agave ovatifolia, gentryi, lophantha, albopilosa, striata, stricta, schidigera, filifera, multifilifera, one or two salmiana ssp crassispina and even a vic-reg (!) are all fine. The rest have been damaged to some extent or another. Hopefully they will all still be here come spring but I know it is early days. All left uncovered this year.

[WayneM]

Bit shocked myself, as a friend of mine has damage his very large montana specimen

My smaller montana unprotected, took a hit.

My Aloe straitula look like seaweed, aeoniums in the greenhouse got whacked too.Hopefully will sprout again from the stems.

I've had a two year old polyphylla which now is a polygoner. ....had airflow, overhead protection, in tilted pot, and still rotted at the core.

Wayne

[ralphrmartin]

Years ago I tried A. montana outdoors after being told it was pretty hardy, when I was living in Cardiff. It died in its 3rd winter, not particularly cold, but probably too wet. It seems it may not be as hard as one might expect.

The plant that has astounded me is Mike's Aporocactus (Disocactus) - I always imagined it growing in a tropical forest in Central America. It is sitting in my apple tree completely unfazed...

[Mike P]

Hi,
Yes I too have lost many plants with that very cold snap! I had intended to replace the cheap packing bubble wrap with the proper stuff, but never got around to it!! And has the last two Winters had not been that bad!
I spent sometime in the Greenhouse yesterday many of my Lithops were just bags of water! and Conos too. Many soft succulents Crassulas, Aeoniums and the like, some may recover I hope.

So first job for March-April get that greenhouse insulated!! with the right stuff, big bubbles, triple laminated ? Anything else, I should be doing??

I'm sure we will all come bouncing back, with new plants and lots of flowers..................

In my experience bubble wrap will help a little with tender plants in an unheated greenhouse but in the end only the addition of some heat will protect them as without it the temperature inside eventually equals the temperature outside and tender succulents won’t take this.
This is very similar to what happened in 2008/2009 when early December snow froze and hung around and the daytime temperatures didn’t rise above freezing for days on end. That year I lost nearly all the plants outside (Agaves, Aloe polyphylla, tree fern etc) and a few Aeoniums in the unheated house but very few cacti in the same conditions.
I noticed yesterday that the Delospermas in one of the troughs outside had been turned to mush having gone through many winters unscathed and the large Agave filifera looks very sickly. Pity as I had hopes of that flowering this year.

[whitesands]

Perhaps plants that are deprived of water in Autumn and allowed to dry out , might withstand the cold better ?
It would be an interesting experiment to do - select a group of identical plants and keep half dry and half fully watered . Expose them to similar cold conditions and observe the result.

[Mike P]

This is the approach I take in the unheated houses and works fine for the majority of cacti and a range of succulents but it doesn't really offer much benefit for the tender ones. I’m really most disappointed to lose the P. lagopus which is a high altitude plant and is very hardy but sadly it’s graft wasn’t and the rot seems to have spread outwards from there.
This will all feed into a talk I am working away at on cold hardy cacti and succulents.

[Paul in Essex]

Years ago I tried A. montana outdoors after being told it was pretty hardy, when I was living in Cardiff. It died in its 3rd winter, not particularly cold, but probably too wet. It seems it may not be as hard as one might expect.

The plant that has astounded me is Mike's Aporocactus (Disocactus) - I always imagined it growing in a tropical forest in Central America. It is sitting in my apple tree completely unfazed...

Yes, the aporocactus has been a revelation. I have one from Mike that I will be planting out in spring.

Agave montana, weird thing is my own plants have taken much colder temps, more snow, longer period of freeze thaw without damage. My best guess is that it is about timing - this year the cold arrived so quickly on the heels of a mild autumn? Even the Beast from the East caused less damage, despite being so late - the winter was mild but still a winter, plants had a chance to go dormant whereas they were still active when the cold arrived this last early December.

But, yes, plants dried out as they go into winter makes a huge diffeence for borderline plants. Winter 2009/10 I lost a group of 3 unprotected Agave mitis at -8C. Tom, at Lullingstone, saw nearly -16C but his Agave mitis were fine under a polytunnel put up before the soil got too wet.

[greatnorthernexotic]

This is my first winter for my greenhouse of cacti and succulents. I recorded a low of -5 outside and -2 inside the greenhouse (heated). First signs for me is that everything survived, even the stuff I expected not to like a moon cactus on dragon fruit root stock. Nothing has been watered since the end of September so that probably helped.

Here's a video I made: https://www.youtube.com/watch?v=tR5SvqU2fJs&t=223s

[Patrick]

As it’s a decent morning for a change I’ve been able to check the outside beds.
As mentioned elsewhere Aloe striatula looks rough and we’ll have to see if it comes back in spring.
Lampranthus also may well have gone.
The Aloe polyphyllas look fine, a Manfreda looks to have survived but outer leaves have gone. Agave gentryi marked but fine, Agaves parryi, mitis, utahensis v nevadensis and eborispina are fine. Selenicereus spinulosus and Nolina nelsonii are fine. Echeveria Perle von Nurnburg a bit marked but looks ok as it was sheltered by a big Lampranthus.
Cycas revoluta leaves have mostly gone brown but I think the crown is ok.
And of course Disocactus flagelliformis looks fine as well!

Mike so are those utahensis nevadensis and eborispina uncovered and therefore wet? I'd always understood they couldn't cope with that. If they have coped I might try some of mine outside here where it doesn't get so cold.

[Patrick]

Agave montana, weird thing is my own plants have taken much colder temps, more snow, longer period of freeze thaw without damage. My best guess is that it is about timing - this year the cold arrived so quickly on the heels of a mild autumn? Even the Beast from the East caused less damage, despite being so late - the winter was mild but still a winter, plants had a chance to go dormant whereas they were still active when the cold arrived this last early December.

But, yes, plants dried out as they go into winter makes a huge diffeence for borderline plants. Winter 2009/10 I lost a group of 3 unprotected Agave mitis at -8C. Tom, at Lullingstone, saw nearly -16C but his Agave mitis were fine under a polytunnel put up before the soil got too wet.

I am also very surprised about the A.montana but this explanation does make sense Paul