When to bring seedlings in for winter?

[CTho]

I have a handful of dates, CIDP, Bismarckia, and sabal palmetto seedlings in containers - how much cold can the seedlings handle?  It’s starting to dip to near freezing (34f / 1c) in Austin over night.

I suspect the S. palmetto would be fine year-round, but I’m not so sure about the rest.

[OC2Texaspalmlvr]

As seedlings i would bring them in for any kind of frost possibilites. Unless you have an obscene amount to move id bring them instead of finding out what cant make it. I agree the palmetto are prolly safe. 

[Rickybobby]

For me. As soon as the temps will slow the growth down I bring them in. No sense on pushing them or making them suffer

[UK_Palms]

I have noticed that small Phoenix and Washngtonia will take -2C (28F) easily without batting an eyelid. Maybe even -3C (26F), providing the following day warms up to like 10C (50F). My Filibusta hybrid seedlings have all seen plenty of lows of -1C and -2C and a few -3C nights. None of which really fazes them. So I don't really need to worry about bringing them indoors until late November when the daytime temperatures stop reaching 10C and -3C freezes become possible. In which case I will move them indoors here say 20th November and put them back outside 10th March. 

But I did leave some Filibusta seedlings and a pure Robusta outdoors for the whole of last winter. They only experienced minor damage, even after a night of -5.5C. But then again, every day warmed up above freezing which probably made a massive difference. Generally speaking, they experienced highs of 8C and lows of 3C during January. The bigger specimens continued to grow and push out new fronds during winter, including a Filifera, a CIDP and Theophrasti. But they aren't exactly seedlings. 

Anything below -2C (28F) and I would be moving them indoors. Especially if the high the next day isn't warming up to 10C (50F). I don't have to worry about that until mid-late November here.  

[petiole10]

There is no prescriptive cut-in or cut-off date for bringing in/taking back out palms when it comes to the weather. The weather does, as the weather does and each season should be simply taken on its own merits. The cusp months such as November heading into winter and later February and March leading into Spring are capricious from one year to another this side of the Atlantic and so timing of moving palms can vary quite considerably from one year to the next.  

Recent history is an excellent example of this: Following a mild winter last year, the Spring was increasingly chilly and April even saw some late frosts. In contrast the year before saw an usually cold end to winter and early Spring but it then warmed up rapidly and from mid April it was equally unusually persistently warm right into what was a hot summer.

On that basis, the movements inside and outside of many of my own palms has been highly varied according to the different ways the weather has evolved each season. So its not sensible or intuitive to fix timings, or give advice based on any fixed timings. The best guide is to know your climate, including your micro climate and make decisions based on how the actual weather fluctuates from one season to another and from one year to another.

In my experience,  Washingtonia very much dislike a combination of very wet and chilly conditions (irrespective of lack of any frost as has been the case to date). My own came inside in the last week, having shown some sign of starting to yellow due to this combination.    Oversaturated soil that is also getting steadily colder, however well drained, is tolerated even less well by this palm than some other palms (relatively speaking) and which are also more cold hardy 

Its no surprise that mine already look better since they came inside from the wind, rain and chillier temperatures overall than usually seen at this time of the year and that have been evident in recent weeks. It Hopefully the lead in to winter will eventually see some mild temperatures c/o winds coming from the more tropical parts of the Atlantic

Edited November 4, 2019 by petiole10

[Dimovi]

I am also in Austin, I have my Sabal Mexicanas and Phoenix Dactyliferas out all winter, but I cover them with plastic for light freezes and may turn on a heater for temperatures in the 20s.

Last year I had a bunch of Sabals (10 - 13 months old) out all winter without any damage, but it was a very mild one.

[Chester B]

Because they're small and in little pots I don't like to subject them to frost.  Last year I brought them in the house but have too many to worry about now so I bought a small greenhouse and lined it with bubble wrap.  I'll also have C9 christmas lights on a thermocube in case we get below 35F (2C) and plan to monitor with a wireless temperature transmitter.  If the lights are insufficient then I'll put in a small plug in oil radiator.  I think I'll finally be done with this project today or tomorrow - it was more work then I expected.

Edited November 8, 2019 by Chester B

[RyManUtah]

I bring mine in whenever it’s supposed to frost. I put them in a box to make less trips and put them in my storage room. I take them back out every morning for sunlight after a frost. I figure, it’s dark they can be inside. It’s light they can be outside. Pots can freeze a lot faster than the ground. A lot of my seedlings are from warmer areas of California and Florida. Being they’re first winter, I don’t want to shock them just yet. 
 

Ones I have dug up locally I just leave outside.