Gonna get cold! already repotted

[The Warm Canuck]

We've had an unusually warm March here. The last two weeks have been warm and my trees have been waking up so I started repotting. Now the next weeks is going to get cold, night temps as low as 10Deg F:


The tress I re-potted in one of my grow beds are 2 x Amurs, an American Elm, a Red Maple and a American Linden. Yesterday, I tried to make a makeshift cold frame and mulched the trees up this morning, as it went down to 30 last night and the top layer of soil was frozen.. I have another bag of mulch should I add more?


I've also repotted multiple Japanese Maples and potted two collected tress, that are in my unheated garage. Should I bring these in the house for those low nights?




Nothing has leafed out, just bud bulging.

 

[namnhi]

How cold does it get in your unheated garage? If the buds start to move, maybe the roots are also active.... I would keep them above 32 degrees.

 

[The Warm Canuck]

How cold does it get in your unheated garage? If the buds start to move, maybe the roots are also active.... I would keep them above 32 degrees.

Usually 5 deg above the outside temp.

 

[Eckhoffw]

Yeah. Stinks but, I’d bring ‘em inside.
Going to get some die back on those budding out, and possible death to anything that has pushed leaves.

 

[The Warm Canuck]

Yeah. Stinks but, I’d bring ‘em inside.
Going to get some die back on those budding out, and possible death to anything that has pushed leaves.

Luckily, nothings leafed out, buds just started getting shiny on the maples.

 

[NateDyk47]

I'm in a similar situation, though not quite as cold (forecasts as low as 18°F, 4 nights in a row under 25°). I haven't repotted any maples yet, but a couple of my JMs have already started to leaf out and the remainder have really swollen buds. They're still in my shed, so they're a bit warmer than outside and protected from wind, but I'm still worried they may be damaged.

 

[Brian Van Fleet]

Luckily, nothings leafed out, buds just started getting shiny on the maples.

The danger of repotting too soon…

 

[Eckhoffw]

The danger of repotting too soon…

Yes. This warm yo-yo weather got me with one repotted spruce -to early- this year already. Gunna be a goner I’m sure.

Not worth it.

 

[The Warm Canuck]

The danger of repotting too soon…

Ya, thanks for that, seems like I'm damned if I do, damned if I don't.

 

[The Warm Canuck]

Brining the trees from the garage inside over night is no big deal, I'm more worried about the ones in the grow bed.

Is is safe to cover most the tree in mulch?

 

[Eckhoffw]

Brining the trees from the garage inside over night is no big deal, I'm more worried about the ones in the grow bed.

Is is safe to cover most the tree in mulch?

Sound like a plan!
Yeah you can temporarily cover them up. You could also throw an old sheet or two over the tops.

 

[River's Edge]

Just don't water the trees a lot if expected to freeze. particularly maples the roots will be damaged! better to let them drain well so they are just damp before expected freeze. I would definitely mulch over the rootball area that will help trap ground heat. The covers look like they will help with wind chill. You should be ok with the ground bed trees mulched. The ones in the garage I would move to warmer locale over night. Best of luck.

 

[rockm]

Brining the trees from the garage inside over night is no big deal, I'm more worried about the ones in the grow bed.

Is is safe to cover most the tree in mulch?

If the tree is in leaf, or recently repotted, consider bringing it inside. Mulch pile should be fine if not. Watering, or at least making sure the root ball is wet, is a crucial part of weathering freezes like this. Water acts as an insulator and lags temperature swings. The water around the roots has to freeze before the root. That process even provides a bump of heat. In dry conditions (we've got fire warnings up here because of the dry air and wind), I water everything in garden beds down before I got to bed.

All this can also depend on the depth and length of the cold. If you've got forecasts of nights below 30 down into the 20's or lower, for days and daytime temps not reaching above 40 or so, the garden mulch beds will probably freeze through after a few days. If you have trees that are pushing leaves in those beds, that can be trouble.

 

[The Warm Canuck]

If the tree is in leaf, or recently repotted, consider bringing it inside. Mulch pile should be fine if not. Watering, or at least making sure the root ball is wet, is a crucial part of weathering freezes like this. Water acts as an insulator and lags temperature swings. The water around the roots has to freeze before the root. That process even provides a bump of heat. In dry conditions (we've got fire warnings up here because of the dry air and wind), I water everything in garden beds down before I got to bed.

All this can also depend on the depth and length of the cold. If you've got forecasts of nights below 30 down into the 20's or lower, for days and daytime temps not reaching above 40 or so, the garden mulch beds will probably freeze through after a few days. If you have trees that are pushing leaves in those beds, that can be trouble.

Thanks for the reply.

None, of the trees are in leaf. All of them are native species, but a few had some aggressive root work, so fingers crossed.

 

[namnhi]

Just don't water the trees a lot if expected to freeze. particularly maples the roots will be damaged! better to let them drain well so they are just damp before expected freeze. I would definitely mulch over the rootball area that will help trap ground heat. The covers look like they will help with wind chill. You should be ok with the ground bed trees mulched. The ones in the garage I would move to warmer locale over night. Best of luck.

@rockm @Bonsai Nut Does this seem contradicting with what you said? Should we water the trees when the temperature is expecting to drop below freezing?

 

[Empty Mountain]

Good luck! Last year in Toronto bud break on my trees didn't start until the third week of April. All my trees are kept outside on the ground, there's always a late season cold snap here so I'm still probably a month away from any repotting.

 

[rockm]

@rockm @Bonsai Nut Does this seem contradicting with what you said? Should we water the trees when the temperature is expecting to drop below freezing?

Yes. Not contradicting at all. Water is an insulator. Water outside of roots in the soil has to freeze before roots in the soil freeze. It is a tried and true method used by farmers to protect against frost--That's why they spray water over orange groves when cold snaps are predicted. The water freezes on the fruit and protects it from cold. Same thing is true of a temporary bonsai protector--roots and all. It's temporary, you don't want soggy roots all winter, but you want roots to be kept moist even through the deepest winter cold. Dry roots freeze quickly, wet roots not so much.

ANd yes, definitely water your trees very well before a night of frost and the trees are out of shelter outside. I do this every fall with every frost and freeze between Oct. and Nov Do the same with some trees in the spring under some conditions--when temps are forecast to be near freezing --36-33 ish--to insure the soil doesn't freeze on trees that I've taken out of storage and aren't yet in leaf.

 

[WNC Bonsai]

Yes. Not contradicting at all. Water is an insulator. Water outside of roots in the soil has to freeze before roots in the soil freeze. It is a tried and true method used by farmers to protect against frost--That's why they spray water over orange groves when cold snaps are predicted. The water freezes on the fruit and protects it from cold. Same thing is true of a temporary bonsai protector--roots and all. It's temporary, you don't want soggy roots all winter, but you want roots to be kept moist even through the deepest winter cold. Dry roots freeze quickly, wet roots not so much.

ANd yes, definitely water your trees very well before a night of frost and the trees are out of shelter outside. I do this every fall with every frost and freeze between Oct. and Nov Do the same with some trees in the spring under some conditions--when temps are forecast to be near freezing --36-33 ish--to insure the soil doesn't freeze on trees that I've taken out of storage and aren't yet in leaf.

WIND ALSO,COMPLICATES THIS. I water my trees on the benches yesterday afternoon then we hit 28 degrees last night and we had some real nasty wind 20-30mph. This morning the soil was looking pretty dry due to desiccation from the wind.

 

[xwintersgloomx]

Definetly feeling this, did some premature repots and now all the tress are back in a heated shed at 2 degrees for the week until it warms up. A couple maples were starting to leaf out. I had some natives under mulch all winter, hopefully leafing out isn't affected for you!

 

[The Warm Canuck]

Definetly feeling this, did some premature repots and now all the tress are back in a heated shed at 2 degrees for the week until it warms up. A couple maples were starting to leaf out. I had some natives under mulch all winter, hopefully leafing out isn't affected for you!

I'm not sure it's fair to say it was premature to repot, with how warm the weather was for how long it was and if the trees where calling for it. Seeing how you have the ability to regulate the temp in your shed, your pretty safe. Just will have to start the shuffle in a few weeks. This has got me realizing that I need a better way to regulate temperatures around this time of year. Either insulating my garage or turning the back porch into a 3 season room.