Bad timing for new trees overwintering

[darzuo]

I recently ordered some trees (a couple of flowering quince (chaenomeles) and a corkbark elm) from Brent at Evergreen and they arrived earlier today. Problem is, it may have been a bad choice of time for shipping and I probably should have waited until the trees were dormant. They should be cold-hardy in my zone with no issue, but they came in with mostly green leaves with just a few starting to yellow whereas most of my deciduous trees have dropped all their leaves already. We're already getting frost at night here and some nights dipping into the high 20s (around -2C), and I dont think these threes have experienced many nights below ~40F yet. I'm worried that it could be a detriment to put them outside without an adjustment period. My options are either put them outside mulched in or having them get by indoors where they wont get dormancy for this year. I'm leaning towards the former as my understanding is that even if the frost damages foliage, the trees should be fine as they are beginning to enter dormancy anyways, but I'd love your opinions. Any help is appreciated, thanks.

 

[Dav4]

I recently ordered some trees (a couple of flowering quince (chaenomeles) and a corkbark elm) from Brent at Evergreen and they arrived earlier today. Problem is, it may have been a bad choice of time for shipping and I probably should have waited until the trees were dormant. They should be cold-hardy in my zone with no issue, but they came in with mostly green leaves with just a few starting to yellow whereas most of my deciduous trees have dropped all their leaves already. We're already getting frost at night here and some nights dipping into the high 20s (around -2C), and I dont think these threes have experienced many nights below ~40F yet. I'm worried that it could be a detriment to put them outside without an adjustment period. My options are either put them outside mulched in or having them get by indoors where they wont get dormancy for this year. I'm leaning towards the former as my understanding is that even if the frost damages foliage, the trees should be fine as they are beginning to enter dormancy anyways, but I'd love your opinions. Any help is appreciated, thanks.

Dormancy is mainly brought on by shorter days, so, unless these were greenhouse grown with artificial lights (which I doubt) they should be ready for some cold. Get them outside and mulch the roots. I wouldn't worry about frosts and light freezes right now, and that exposure will hasten full cold hardiness.

 

[darzuo]

Dormancy is mainly brought on by shorter days, so, unless these were greenhouse grown with artificial lights (which I doubt) they should be ready for some cold. Get them outside and mulch the roots. I wouldn't worry about frosts and light freezes right now, and that exposure will hasten full cold hardiness.

That's what I figured, thanks.

 

[Leo in N E Illinois]

Not trying to be harsh, but never buy material you plan to treat as hardy from a warmer climate after about August 30. Trees need 30 to 60 days of steady declining temperatures to make the physiological changes for full winter hardiness.

If you can find a way to keep them cool at night, between 40 F and 32 F for about a month or so you can then risk going colder.

Depending on efforts required, might be easiest to just run them indoors as subtropical for this winter.

Or if the expense was "fun money", just leave them out, heal them in ( bury pots in garden bed ) , and see if they make it. Flowering quince are fairly resilient.

 

[darzuo]

Not trying to be harsh, but never buy material you plan to treat as hardy from a warmer climate after about August 30. Trees need 30 to 60 days of steady declining temperatures to make the physiological changes for full winter hardiness.

If you can find a way to keep them cool at night, between 40 F and 32 F for about a month or so you can then risk going colder.

Depending on efforts required, might be easiest to just run them indoors as subtropical for this winter.

Or if the expense was "fun money", just leave them out, heal them in ( bury pots in garden bed ) , and see if they make it. Flowering quince are fairly resilient.

Yeah, I agree I should've held off. They weren't terribly expensive as they're just young material so it isn't a huge loss either way but I want to try and keep them alive since they're here. You think that running them indoors for a winter is a better bet? My thought is that the shortening days is what triggers the tree to begin to undergo the physiological changes, but I'm no expert. I suppose it probably depends on species and is a combination of several factors including temperature. It wouldn't be any more difficult for me to keep them indoors, but I thought if they would be fine outdoors that it would be better for them.

 

[Leo in N E Illinois]

It is often stated that day length is "the trigger" for dormancy, yet the number of species with science proven day length triggers is fairly small. More common night temperature over time has been a proven trigger.

So we "suspect" day length is the cue. But more often temperature is the cue, but for the vast majority of trees, there is no documentation on which of several strategies is the cue to trigger winter dormancy. The above 2 are most common strategies for cold hardy trees where data exists.