When part of the tree breaks dormancy and grows and the other part doesn't. Or when it's past time for them to break dormancy (based on other plants around you) and it doesn't.

I mean you can test for dead branches in a couple of weeks probably (since you didn't say where you are...I am making assumptions), but it's much easier to just wait.

My advice after 2012 is to literally wait until early June unless the main truck shows no green in April.

time depends on your zone but assuming you are between 3 and 5

I'm in zone 5a but the temperature went down to -30

What plants are you worried about?

I hit -27 and not worried unless we have sustained frozen soils through March or another round of sustained extreme temps.

Well a number of years ago, we hit -27 (and I'm zone 7a)..and there really wasn't much damage. Crepe myrtles froze to ground, that's about it.

Where are you, dbarron?

I'm concerned about many woody plants, but high on the list are: Acer tegmentosum 'White Tigress', Catalpa bignonioides (Southern catalpa), Purple Fountain Weeping Beech, Acer 'North Wind' which is a hybrid between A. pseudosiboldianum and A. palmatum.

The average minimum low for a zone 5 is -20. So a drop for a day or even a few another 10 degrees is not pushing the bounds excessively :-) For woody plants fully hardy to your zone, dormant and established in the landscape, you may not see any damage at all. Borderline hardy plants could experience some dieback or cold distress. The greatest risk would be to broadleaved evergreens (but few are z5 hardy to begin with) and those subjects that are relatively newly planted.

I would have a greater concern with moderate temps (40's-50's or more) that could encourage your plants to start out of dormancy, only to be hit back when more normal, below freezing winter temperatures resume.

you will start to see issues at bud break .. if any ... it can take months for dead buds to regenerate ... presuming the plant itself wasnt damaged ....

you may also see lack of bloom on the early bloomers .. say redbud or such ... but then otherwise leaf out ok ... so what if you lose one year of flower ....if it lives.. it will bloom next year ....

and then all thru summer ... if there was root damage ... in other words ... if the plant comes out of dormancy on stored energy.. but once thats used up.. it cant generate more energy thru sunshine ....

think in tree/shrub time.. and dont give up in april ... it might take some time ... but by fall.. the next planting season after summer ... i might be replacing things that didnt please me.. by then ...

ken

ps: it ALWAYS helps to include your location..

btw ... older more established plants can usually handle it better than plants that might not be fully established due to planting last year.. or in fall ...

ken

Acer 'North Wind' is supposed to be fully Zone 4 hardy, so I don't think you have to worry about that one at all.

Patience . . . Either they will leaf out fully in spring or they won’t. And if they don’t, more patience is needed since on many plants, buds can be killed back without the underlying wood being damaged and so they may rebud and put out leaves on branches that appear dead. I have also had branches on borderline shrubs leaf out but then lose the leaves due to branch damage that wasn’t obvious. Gardening is my greatest life lesson in patience (which is something that doesn’t come naturally to me.) IME, I can prune out dead and damaged wood sometime past midsummer when I know for sure what if any branches won’t recover.

I agree with waiting until June. When everything else is growing beautifully, then you notice something that looks a little sick and not putting new growth out like it should.

I also agree not to jump to conclusions either and move too fast. My Tsuga canadensis was pretty yellowed last spring and had some dead branch tips. We had little snow so my fear was that it had root damage to boot.

By the time bud break in another month, the needles have greened up and new growth was unimpeded. By summer the tree showed little sign of winter damage.