It needs watering but going to freeze

[Japonicus]

Perhaps @0soyoung would like to put an 0soscientific spin on this.

Going to be in the upper teens next couple nights, good thawing during the day. Starting transitional month...

Just moved my trees that were exposed to the drying Northerlies back in the cave,
and found that the mugo clump I divided last year and put in a pond basket was lighter than it should be.

What happens to the roots here if I water now and the temperature drops in the teens in pots above ground?
If I wait till morning and water, the 50 or so degree tap water would do a quick thaw and flash freeze, and probably damage the roots.
At least that's my intuitive take on that.

 

[Forsoothe!]

Put some ice cubes on the surface (when frozen).

 

[Japonicus]

Put some ice cubes on the surface (when frozen).

Ok, so I have an old bag of ice in the freeze I wouldn't give a pet to drink from who knows what month of, last year I'm hoping
I'll top dress the soil some next couple days, and water in good Sunday. Then more rain moves in Monday.

I knew that...I knew that

 

[Dav4]

I'd water the pot before the soil freezes, then mulch the pot. Then, I'd water the mulch... in that order

 

[Japonicus]

I'd water the pot before the soil freezes, then mulch the pot. Then, I'd water the mulch... in that order

I'm hoping this is the old Homefront part of you @Dav4...up Boston ways?
Doesn't matter really the weather particulars are given. I just didn't want the roots to swell and bust
on a molecular scale I mean, ya know?

 

[Forsoothe!]

Don't get crazy with the water. Look at the foliage. If it doesn't look damaged, don't overdo the water thing.

 

[Dav4]

I'm hoping this is the old Homefront part of you @Dav4...up Boston ways?
Doesn't matter really the weather particulars are given. I just didn't want the roots to swell and bust
on a molecular scale I mean, ya know?

The roots will only swell/burst if the water within the roots, and particularly within the cells in the roots, freezes. In order for that to happen... all the water in the mulch would have to freeze (until this happens, the mulch temperature and everything beneath it will not fall below 32 F), then all the water in between the soil particles in the pot would have to freeze (again, the soil temp stays at 32 F until all the water is frozen), and then the water within the roots would have to freeze, and this would happen at temps wayyyy below 32 F. That's very unlikely to happen if the pot is on the ground, mulched and heavily watered, even with temps well below zero. I have actually watered trees before a hard freeze as a means of protecting the roots... the worst thing that I've had happen was a broken pot.

 

[WNC Bonsai]

When water freezes it actually gives up heat, that can be beneficial. Even water in intercellular spaces may freeze and give up some heat that helps protect the cells themselves from freezing. It is important to keep trees from drying out in the winter.

 

[Japonicus]

Don't get crazy with the water. Look at the foliage. If it doesn't look damaged, don't overdo the water thing.

Makes sense. It just caught me by surprise when I picked the pot up. Summertime this would be more stressful for the tree.
There's some weight, but scary how light it felt. Being rather dormant helps sweeten the deal.

The roots will only swell/burst if the water within the roots, and particularly within the cells in the roots, freezes. In order for that to happen... all the water in the mulch would have to freeze (until this happens, the mulch temperature and everything beneath it will not fall below 32 F), then all the water in between the soil particles in the pot would have to freeze (again, the soil temp stays at 32 F until all the water is frozen), and then the water within the roots would have to freeze, and this would happen at temps wayyyy below 32 F. That's very unlikely to happen if the pot is on the ground, mulched and heavily watered, even with temps well below zero. I have actually watered trees before a hard freeze as a means of protecting the roots... the worst thing that I've had happen was a broken pot.

Thanks Dave. I've picked up a few ice cubes (frozen to the core pots) even this mild Winter
and I didn't mulch this year, as I never even got the snow tires on my wires car.
15ºF was the low, and actually was in the Fall right after Presidents day I believe. I think this will get it through till Sunday
top dressing it like this a couple times. So I never heard of protecting the roots with water prior to a freeze. Of course Southern
orchards spray the foliage to protect the buds and fruit with a layer of ice, that I knew, but not the roots deal.

 

[Dav4]

Of course Southern
orchards spray the foliage to protect the buds and fruit with a layer of ice, that I knew, but not the roots deal

It's the same principle... water releases heat as it freezes, thereby delaying the cooling of anything it surrounds. Fwiw, the soil in colanders and pond baskets will lose moisture faster then when in any other container. If the pond basket was noticeably lighter, I would water it sooner then later... those ice cubes aren't going to do much if the soil is truly dried out and you won't hurt the roots one bit.

 

[Japonicus]

It's the same principle... water releases heat as it freezes, thereby delaying the cooling of anything it surrounds. Fwiw, the soil in colanders and pond baskets will lose moisture faster then when in any other container. If the pond basket was noticeably lighter, I would water it sooner then later... those ice cubes aren't going to do much if the soil is truly dried out and you won't hurt the roots one bit.

Ok will do. Thanks for your input. Precisely why I started this thread.
Edit, and oh BTW, this IS my 1st pond basket. I figured that out today.
Summer it doesn’t go unnoticed and we’ve had so much rain this Winter.

 

[Dav4]

Ok will do. Thanks for your input. Precisely why I started this thread.
Edit, and oh BTW, this IS my 1st pond basket. I figured that out today.
Summer it doesn’t go unnoticed and we’ve had so much rain this Winter.

We've had more then 22" of rain in my back yard so far this year. Still, I think there was one week in January where I felt the need to water... honestly a first for me as I normally wouldn't need to that time of year but it was SO warm.

 

[Japonicus]

those ice cubes aren't going to do much if the soil is truly dried out

You're right. I figured by the time I made it home just before dark tomorrow with a high in upper 30's
that there would still be the remnant of ice cubes atop the soil and these baskets are pretty deep, so nil watering would occur.
Watered/mulched/watered, no worries, and the mulch was already weathered and moist and treated with insecticide 2 months ago.
The mugo hopefully has a lot of new roots on one side after sawing apart. Let's hope it didn't dry too much.

 

[RKatzin]

Most of my winter it's either raining, freezing, or covered in snow. I don't worry about water until this time of late winter when it's not raining and it's warm enough to thaw, but not enough to induce breaking dormancy. It's been a week since the last rains and I spayed everything down good for the first time yesterday. Even though we're still freezing at night I'll continue to water about every three or four days, until it starts raining again. And it will, a lot.

 

[Arlithrien]

Water is really good at regulating temperature. My understanding is that if you water before the freeze, the water will maintain temperature longer and keep the plant warmer than had you not. Perhaps water with lukewarm water.

 

[M. Frary]

It's a Mugo Pine!
Not some sissy Japanese Black Pine.
They enioy being frozen.
Mine have been since before Thanksgiving.
They will thaw then freeze again quite a few times until spring.

 

[Japonicus]

It's a Mugo Pine!
Not some sissy Japanese Black Pine.
They enioy being frozen.
Mine have been since before Thanksgiving.
They will thaw then freeze again quite a few times until spring.

I know right? LOL @ not a JBP. It’s a new division less than a year

@RKatzin this will be the 3rd time I’ve watered this Winter being so much warmer.
My trees are sheltered in a spot under my sunroom with no rain except for the ones
I move in and out since I didn’t mulch this year, plus my 1st experience with a pond basket
the tree was exceptionally dry unlike other Winters with mulch keeping the moisture a bit more constant.
I have watered frozen pots before without a care, this one just felt different, thanks for all the replies.

 

[Wires_Guy_wires]

What happens if it rains in between frosts? Use tiny umbrellas?

I don't think outdoor trees should need that much protection or pampering. If they do, I shouldn't have them. But that's my personal view for my personal plants.

 

[RKatzin]

Ok, here's the drill. It started raining late last night. Then it froze overnight and started snowing early this morning. Now it's thawing again and looking like more rain. Maybe, hold your bets. Lol

 

[Japonicus]

Ok, here's the drill. It started raining late last night. Then it froze overnight and started snowing early this morning. Now it's thawing again and looking like more rain. Maybe, hold your bets. Lol

I get that. It's part of transitioning to Spring, or just typical of Winter, and for all my other plants I had no consideration.
The overly dry part, newly divided...suddenly rehydrated was the initial scientific query, what happens...can it be counter productive to
get the tree watered in well from a dehydrated state, then freeze? The mulch and water helped protect as Dave suggested.
At least I followed the good advice
It's just a position I'd never found myself in. As silly as it seemed to ask, I did. It was -18ºF here 2 years ago
and it rained when it did, and I cared not, well the cold bite was unpleasant and that was before I bought this clump.
The Northerlies really dried this basket out in a day and a half. I know better now. Gotta take care of my babies.