if they were dormant.. i dont understand why the cold would have bothered them .... or how they could have froze .... or why they were leafed out ....

i would consider both types as root masses .. and hopefully .... those will spring back ...

when i used to get the WINTER fever.. and bought early ... too early ... everything got potted and put in a kids wagon ... and put in the garage ... and pulled in and out as weather allowed ... kept them cold enough to stay dormant.. or protected enough.. if they were already a bit active ...

but.. i never bought in february ... lol ... but maybe thats a MI thing ....

ken

ps: i would return them.. its their fault.. to be selling stock this early .... even in z6 ... imo ....

No, assuming the plants are dormant it's a great time. If they're not..then it's a terrible time (lol).

Ken, we'll be fully into spring in a month (ie daffodils are showing yellow right now).

Plant roots frozen in a container is not at all the same as frozen in the ground. And there are not all that many plants that can/will survive that sort of exposure. The only positive note (I think ) is that they were not exposed to below freezing weather for long?

btw, this is the time bare root stock is always introduced for sale. And is an ideal time to plant as well, provided your soil is workable. But if planted in a container, you will need to protect from any unexpected, below freezing cold spells.

The "official" start to spring is only 33 days away :-) And that won't be a moment too soon for me!

Yep, the forecast just shows some light freezes (25-27) in the foreseeable future, so it's nearly done (I hope). Yeah, it has seemed like a long winter.

Ground soil freezes at a pretty consistent temperature....right around 32F. It doesn't get appreciably colder than that and often warms as one goes deeper into the soil profile. Most plant roots tolerate that sort of cold just fine. But that is hugely different from root systems exposed to ambient air temperatures - anything in a container that is not protected from the cold - that drop below zero!! Few plants are able to tolerate that!!

You cannot reasonably compare containerized plants and their ability to withstand freezing temperatures and the behavior of the same plants planted in the ground. It is comparing apples and oranges!!

Here's my oops I'm still regretting it and I haven't even noticed the holes these missing tender perennials will leave. Commiserate away!

I would really like an explanation of just how this works. Let's say, for example, you have an ambient air temperature of zero, and no snow cover. What is keeping the upper level of the soil anywhere near 32F? The surface of the soil should be zero, right? So there is a temperature gradient from the surface to deep enough that the temperature is stable. I *think* that is something like 45F at 20 ft down.

Among other things, you are saying that civil engineers are all incompetent. One of the standard statements on building anything permanent in the north is that the footings have to be below the frost line. Here, that is 5 or 6 feet. So they are saying that is how deep the ground can freeze. That is a lot deeper than 6 inches.

I respectfully disagree with your statements, gardengal. Based on my experience of over-wintering containerized plants of various sizes in an unheated garages and barn, I can attest to the fact containerized plants can and do survive winters when the ambient temp is far below 32F. Plus, what difference does it make if the ambient temp gets any lower - frozen is frozen. Just like you can't be any deader than dead - same principle. I know you have professional experience and I respect that, but those of in colder zones do have first-hand experience with this; I don't know that those gardening in milder climates can make the same statement.

Madgallica -- Not sure who you directed your comments to, but about the 6" - that was me. I was trying to explain something different and didn't do a very good job at it. Here in MI the frost line is about 3.5 feet. I removed my comment about the 6" because not being able to explain what I'm trying to get at creates confusion. The ground absolutely positively freezes solid here. Regardless of the depth - frozen is frozen, that's not what kills the plants; its the freeze-thaw that does it.

In my opinion, the problems we have in milder climates are repeated freeze/thaw cycles (esp in early spring). I lose more plants that way. I believe staying in one state or another would probably be more forgiving.

LOL!! You think it doesn't get cold here?? Frozen container plantings are just as much a concern here as they are in colder zones. Not all plants will react in exactly the same manner but there is a temperature point below which the moisture in plant tissue - roots - freezes and bursts cells. When that happens, there is no recovery. So frozen is not just frozen.....it is variable depending on the plant, its vulnerability to cold, the size of the container and surrounding soil mass, how fully dormant it is, how much moisture is retained in the tissue and the extent of the exposure, etc.

Feel free to disagree all you want but this is all very thoroughly documented scientifically. And why one sees threads about this topic every year as spring rolls around......."why didn't my containerized XYZ survive winter"?

btw, I have experienced this firsthand myself. Containerized plants exposed to below freezing temperatures are just as common here as elsewhere. And in most cases the outcome is not hugely positive. Even the retail nurseries and garden centers here that are open for business year round move their plants under cover to receive at least solar heat to prevent freezing and cold damage.

I didn’t mean to start a divisive topic. Lol. :) Thank you for all of the input, though! I’m learning lots.

Ken, the wagon is an excellent idea. May have to get one of those! I thought about returning them, but I would feel dishonest. There was nothing wrong with the plants. They were perfect. It was my own fault.

rob333, how sad! That’s the worst, after caring for them for months, and then forgetting one time. :/ that’s all it takes!

Mxk3, ouch. Losing that Rodgersia must have been devastating! I’m sorry. Glad I’m not the only one.

As far as the freezing, all I know is the phlox in pots is dead, the ones in the ground are not. I’m assuming it’s because they were fresh and not settled in. If they had been grown in the pots before being exposed to the freezing temperatures, perhaps they would have made it. I have several other potted plants that are doing fine, but they were potted while still actively growing.

Also, just wanted to correct the assumption that they had broken dormancy. Almost all of the phlox were still dormant, at least as far as I understand dormancy! :) They had growth buds below soil level, but no growth. The clematis had begun to sprout, but I think they made it although the fresh growth died.

Of course there are variables, I think we all know that. And I think we all know I am not a soil scientist. What I do know, however, is that is entirely possible (easy, even) to overwinter zone-hardy potted plants in brutally cold conditions --> I'm talking temps in the negative numbers conditions here - not the wimpy 30s or 20s - and the potted plants are solid blocks...complete, utter, unequivocal blocks of frozen solid soil.

The key here is that protection from exposure is important to avoid of quick temp swings because the soil may thaw at the surface and then re-freeze. But it isn't the frozen soil that's the problem, it's the freeze-thaw that damages the plant, made worse if there's a lot of surface moisture (snow/ice) on an exposed container that re-freezes. So yea, I agree -- leave the container on the patio exposed to sub-zero temps to mid-40 temps and rain back to 0-range temps and there's going to be a problem. But not a problem if the container were in a protected location where the temp variability isn't as rapid and there's not further surface moisture build-up - it'll survive just fine.

Dilly - how do you know they're dead?

It was a pretty rapid freeze thaw, unfortunately. Went from 50’s to 10 in one day, stayed frozen for 3-4 days, and then back up,

I’m pretty sure they are dead because the roots froze to that unfortunate state of translucency from which I have never seen roots recover. I’ve seen it many times with my dahlia tubers and peonies. If they are firm and white, as the phlox I put in the ground are, then I’m good to go. If they are translucent and ooze a little water when lightly squeezed, they never come back.

We don't even have freeze/thaw cycles here and cold weather damage to contanierized plants still occurs. This issue is being grossly understated!!

There is no need to take some nebulous advice from an online discussion forum. You can research this very easily on your own - there are countless articles that explain the damage to plant roots (or other tissue) once the water they contain freezes. As I attempted to explain very clearly previously, frozen ground soil temps are vastly dfferent (and tend to be significantly higher) than the ambient air temps unprotected containers are exposed to. Bonsai websites and texts often have the most detailed info about exposure to differing winter temps and root damage/death. If it was not such a big deal, bonsai enthusiasts would all leave their trees outside all winter......just a small clue but they do not. Even in quite mild winter climates!!

I completely agree that cold damages plant tissue, and that containerized plants are much more at risk. I also agree that there are many variables such as which plants, how cold, how long, how much moisture, etc. I think sometimes plants are hardier than we give them credit for, but also I know that experimenting with keeping them exposed like that opens up a lot more risk and results in a lot more loss. Thanks to both sides for the information provided! I appreciate it. :)

Go look at some of the soil temperature maps and you can see the difference snow cover makes. Even though frost can still go deep up here with snowcover range from the 2" depth to the 20" depth might only be a few degrees below freezing. When there is no snow cover is when you start to see those shallower temperatures start to get worrysome....teens and low 20's.

"We don't even have freeze/thaw cycles here and cold weather damage to contanierized plants still occurs."

What containerized plants? Plants hardy down to zone 3-4-5 aren't going to get damaged by the "cold" that occurs in the zone you have stated in your profile. Tropicals, maybe - but not the tough stuff.

The accepted norm that I recall is 1 to 2 zones hardier than your zone, as a recommended safety factor for winter in unprotected containers.

And even then, with polar vortices :)

Nearly all my plants are in pots...and will often freeze utterly solid, for days on end. Obviously, not months at a time ... but most of my little things in tiny terracotta pots (anemones, auricula, lewisias, sempervivums and so on) may be icicled for a week or so. Amazingly, they never die...although I think they do get a chance to thaw out quite slowly as my garden is orientated west so no brutal morning sun. Have had a couple of less happy times in pots outside my east facing front door, when cell death has occurred by a too rapid thawing from the morning sun. Yep, although I am in the not too freezy UK, there will always be a few days of frozen solid pots every winter. Last winter, lulled into fulsome growth, the 'Beast from the East in mid March wiped out all the early plum blossom...but the pots were fine.

I sprayed my seedlings with a diluted vinegar mix that I use for cleaning/air freshener. (I use another mix to fight dampening off on certain cultivars which I thought I was using) . Apparently I need to get labeled spray bottles.

Ah, a few years ago, I also picked up the wrong spray bottles. My hand closed on the weedkiller I used for customers drives and gravel paths...which I then sprayed liberally around my garden (I think I thought it was either a mild fungicide or foliar feed). I wrote about it on here (probably minimising the utter catastrophe and employing some terribly strained humour as is my wont). I was, in fact, devastated enough to enter in to a completely new gardening frame of mind where I simply stopped the whole planning, hoping, waiting thing (I had murdered many lovely tree seedlings and plants in their 3id and 4th year of growth, awaiting eventual transplant and was stupefied with grief.

Obviously, I got over it, started over and got back on the horse...but I no longer count a single chicken before it is actually hatched and clucking.

I remember that Campanula, it sounded awful then.

Oh man, you guys need to check those spray bottles!

I live with all sorts of jars of chemicals and I Know better, but I still forget to label IMMEDIATELY. I remember you doing that, Camp. That is something I would do.

Oh, Camp. That’s awful. Absolutely awful. I would have cried. For weeks

I did have a little wail.The taste of self-inflicted misery has a particularly bitter flavour, that's for sure. Sweetheart took it upon himself to remove the (copious) evidence while I consoled myself with a mass of cheap begonias (and pelargoniums (we were already well into summer). It was a suggestion from here (possibly Babs?) Filled every pot with shades of red! Defiance!

My garden oops was this past weekend.

I had a potted clematis that I put next to a bush, thinking that it will climb up into the bush and become a bush-covered clematis flower-thing. Well, it never did, so this year, I thought I would re-locate the pot.

I felt empowered that I was doing the right thing, so I pulled the clematis away from the bush, carefully unwinding what I could to save what recent spring growth that I could. Finally, I got it...but wait, there was still some clematis vines on the bush. Oh well, I think I saved most of it, right? Surely it was just a missing small segment from a branching here and there, and was a reasonable loss to accept.

I relocated the pot but that vine nagged at me. I finally went to look. As I finally untangled it from the bush, it turns out there were 2 additional vines of growth that I had somehow torn loose from the pot. These vines were over 4-feet each. I am not sure how I tore them away from the pot or when, but now I have a big regret of losing these two stems, which if I had just carefully unpryed them like I was doing right now, could have still been saved and been a part of the pot transfer.

^^ Well, on the bright side, the clematis will send up new shoots from the base, so I doubt you lost it - although it may be a bit sparser then you'd like for a while.

Most types of clematis benefit from being pruned back in late winter/early spring, so I agree that losing a couple of long dried stems at this time of the season is NBD.

btw, most clems will need a generously sized pot as well as the deep planting that their inground planted cousins prefer.

Here in Texas, I grow them with rocks over their roots a bush to shade their ground around the roots and not in FULL sunlight. BUT I actually have to move one into more sunlight because my live oaks have grown too much. Shade is good for them here in hot Texas but too much is no good too. I meant to move them this winter but I was too busy building. Unfortunately shade is where the grey moisture outlet is.