The last time I remember it doing this in February, everything I have sailed right through without damage with the exception of 'hardy' Fuchsia Double Otto (lost poor Otto) and the 5 year old zonal geraniums on my front porch. (I think the zonals would have been OK, but I'd covered them with old tablecloths and the wind blew the tablecloths off). Fuschias magellanica suffered some tip damage that was easily resolved.

I am feeling a little bit uneasy about the forecast given the amount of budding and leafing out many of my emerging perennials and shrubs are showing, but considering we are supposed to have possible 50 mph winds with this weather system, there is little I can do to prepare. I'll move newly germinated stylophorum, magnolia wilsonii, species lily in their seed flats to a protected spot temporarily, cross my fingers for the rest.

I think I'm going to be thankful I resisted doing any major pruning over the weekend, but I did jump the gun on my roses :(

I think I live in a little mcroclimate here in North Marysville (1 mile south of Smokey Point). Some say we're Zone 8; others say it's 7b, but I'm more inclined to believe it's 8b! It's usually 5 degrees colder than it is 1 mile from here :( We had a session that lasted for about a week in January with the temps in the teens that caught me completely off guard! I'm terribly concerned about my Ligularia dentata 'Othello'; those cold temps literally melted everything above grade, but I'm hoping the root system is OK. Everything else seems to have weathered the first bout beautifully; I don't know if they will tolerate a double dose of those temps though.

Try at least a quintuple dose with a low currently predicted of 15.
Cistus has emailed warnings saying that it's never been predicted to be this cold this late. Kiss all that new growth bye bye.

The record low (-3 degrees F.) for Portland was in February 1950. The coldest March temperature (19 degrees F.) in Portland was during 1989.

Here is a link that might be useful: Climate Data Summary

I'm wishing I had not moved some young trees in my back yard last weekend (before the arctic air was forecast, of course!). I have a parrotia persica, amur maple and a gingko that all got moved. A limelight hydrangea was moved into a pot, too... but I can cover that. The dog probably would find any other coverings to be interesting new toys, as he did with the styrofoam spigot covers. (sigh... keeping fingers crossed)

albertine: Wow, you have Michelia! I'm jealous, where did you get it?

Is this what they call a "cold snap"?
It was awfully spring-like on Sunday.

I'd say to give priority to that Dicksonia. If the temperature falls below about 20F, it's almost certain to die. The Abutilon might get hammered too, depending on what kind it is. But it is a more replaceable plant, or it may grow back from the roots or large branches, whereas with the Dicksonia you only get one chance.

If anyone still thinks it is "springlike" at dawn Friday morning, you are in quite an amazing microclimate. I'm optomistic that this cold spell will not be as severe as it could since the 'arctic' air that is coming towards us is not as cold as it often is in these events. This (and the fact that it is later) makes this freeze quite different from the Feb 89 blast.

I covered the Dicksonia for sure. I felt like I was playing "Sophie's Choice" out there.
The Michelias are not covered and are a science experiment - they are sited as foundation plantings so if they can't take it I'll want to rethink them.
Undercover, they all came from Cistus but one, from Greer. I've got M.figo Port Wine ( I covered that one, it's small), wilsonii,platypetala, yunnanensis, maudiae, doltsopa, and skinneriana. The skinneriana was defoliated by the last wind, but it was planted this fall and it could have been dehydration.

First time ever, but I spent yesterday putting cages with double remay over some of my tender 'babies'. I am worried more about the forecast winds than temps in the teens, as last year we went briefly to 11oF and nobody suffered damage. Also did some watering. I do expect to loose the big hebe that moved a week ago; oh well. I was here in 1989- the year that I lost my fascination with grafted roses.....

Zone 7 is the mountains. Lowlands are Zone 8. Compare Sunset and USDA maps, USDA 7 lines up with Sunset 1.

To understand them better, Michelia and Manglietia = Magnolia. Same care and placement as other evergreen magnolias of similar, often borderline hardiness. That is, warm sheltered positions with good, moist soil. Potted specimens in garden centers often have foliage mildew, resulting gaunt appearance. Not as prevalent in gardens, probably due to more even soil moisture.

Clarification: magnolia foliage mildew not as prevelant in gardens.

Well, I just spent the last hour wrapping up a couple of larger subtropical bamboos I have had in the ground for several years(what a pain)!!!! I usually just let them die back and wait painfully for them to recover in the summer only to see them take another hit the next winter. This time I had too much nice new growth to have this happen.
I have a nice Crinodendron hookerianum(one of my favorite plants) that already has die back but I think it will do OK with a bit of pruning this spring! I still have a bit of snow left over from a few days ago!!! It will be interesting to hear from everyone on how their plants do if indeed this front really materializes.

Elsewhere in the same USDA 8 that you are in but closer to the Sound 2 nights below 20F forecast for Seattle.

In closely tracking this weather event, it has become apparent that the forecasters don't really have much of a clue but they are doing their best. Right now (now that it's 10:30) I think tonight will be about as mild as last night for the Seattle area, because a cloud deck has somewhat spontaneously built up. Some of us north of Seattle may see snow, though it has not been forecasted. Tomorrow night is really the one to worry about. It could be much colder. This is a unique weather pattern, and even less straightforward than the usual pattern of our 'arctic blasts' when the cold just marches right down out of the Yukon. This cold air is being pulled towards us from the ENE by a pressure gradient that is difficult to measure, because the high and low pressure systems on each side are relatively weak. As I'm sure you have noticed, the cold air with this one is EXTREMELY dry; this always happens in artcic blasts, but dew points are even lower than usual PRECEDING the arctic front! Other interesting dynamics could also develop: right now it looks like a low is trying to form off the Oregon coast, which could make things very interesting with lots of snow if it really amounts to something. The computer models used by the meteorologists are really having a hard time handling all of these unique dynamics together.

There are a few very cold microclimates near sea level that are a high zone 7. I know that the Olympia airport is one: their average coldest temeperature each winter over the last 50 years is 8.9F. I suspect there are more places like this especially in Southwest Washington, west of the I-5 corridor and east of the crest of the coast mountains. That is where the cold air builds up when that dry easterly flow comes off the mountains. Other severe frost pockets like the Arlington airport are probably very close to zone 7.

Whatcom County has many areas where the average low temps in winter fall below 10oF, putting us in zone 7b. Just a few miles south, in Bellingham city limits, there are areas that rarely see temps below 20oF. And there are quite different microclimates throughout the area with parts of Sumas/Everson truly zone 7 and winter temps often dipping below 0oF. Add to that outflow winds in much of the outlying county, and the plants suffer dessication during these Artic Blasts. So far, Environment Canada's forecasters seem to be more accurate (as they often are) on the low temps associated with this storm, but I prepared for the worst.

Last night at our place, east of Duvall, we hit 24. Not even as cold as in December. Very dry as you were saying Ian. This morning my car had no frost on it at all. No scraping required. As I drove to work there was a fair amount of debris on the road. It didn't seem windy at my place. We seem to be esacping the worst of Ice Storm 2006.

Keeping my fingers crossed.

jb

I'm not uncrossing my fingers yet either, not sure what tonight might bring.

We have no frost here either with a low of just 30 (4F warmer than yesterday morning) and this is spitting-distance-from-the-ocean-every-rose-is-going-to-have-mildew zone. How odd -- I quickly looked out this morning and assumed it was warmer, but I have drooping hellebores indicating freeze. And wind. And static bad hair.

But the good news is, if it doesn't get much worse than this I don't expect to lose plants.

Last night the temperature remained relatively mild because the wind kept up. The dew point at SeaTac (the temeprature at which frost/dew forms based on the amount of moisture in the air) is now down to an amazing -13F. With relative humidity of 14%. It's not too different for most of our other weather stations. Basically what that means is, once the wind dies off and the sun goes down the temperature can pretty much fall like a rock.

Tonight will be interesting, and is the one to worry about I think. Let's hope the wind does not die off completely! We will probably see lows all the way from the single digits to the 20s depending on where you are. If you are by the water or in an area that favors air movement you are likely to escape relatively unscathed. If you are in a sheltered valley, you may get very cold indeed. To get a feel for how much colder the air mass is now than 24 hours ago, one has only to look at the weather data for a site in the mountains such as this one:

Here is a link that might be useful: White Pass Weather

Ian, are those temps farenheit or celsius? In either case it's getting colder.

jb

That's farenheit, but of course that is up at 6100' elevation. It will not be -9F here but yes it could potentially be much colder tonight. If you look at a report from a lowland weather station, you can see the same weather pattern, though it is not as pronounced because our daytime temepratures are warmer. But you can still see dew points/humidity falling off dramatically and the temperature quite a bit cooler than it was at this time yesterday.

BTW my low this morning on a hill west of Poulsbo was 22F. It is still 28F now, and the wind still howls. Some people are without power.

Here is a link that might be useful: Sea Tac Weather

Yesterday when I got home at 5pm it was 36 degrees outside. Inside the greenhouse, which is only heated by the sun, it was 56. I am glad I don't have alot of plants in there as the temp swings during this kind of waether wouldn't be the best for them.

jb

Ian
Help me understand what you are saying about the wind.--

I understand that with more wind there will be less frost, (because of sublimation?) but are you saying that a low temperature itself is not the damaging factor, but the frost is?

Or is it that with wind the temperature will not be as low?

Does anyone in Olympia or Bellingham think they are in the same hardiness zone as the tops of the Olympic and Cascade mountains? That's what you have to do to call these places Zone 7. The only sensible and practical way to interpret the USDA map is to ignore the goofy little detached pockets of Zone 7 surrounded by Zone 8 near Olympia (and Zone 9 at Port Townsend, which is even more anomalous and isolated) and figure these are in the same zone as all the land immediately around them--as is done in the Sunset WESTERN GARDEN BOOK.

Plantknitter, with more wind, if it is an E, N or NE wind as we usually have in these events, that causes the humidity dew point to drop way off. This is why you don't see actual white frost on anything even if the temperature is well below freezing. Usually though, this is actually more destructive to plants than frost that occurs under calm conditions and high humidity (i.e. a usual white "frost"), because the very dry air causes plant leaves to become dessicated and frozen at the same time: moisture cannot reach the plant tissues and they die. It really depends on the plant though, and some other factors. Plants with tough fleshy leaves, including many succulents, can handle this better than a frost with high humidity. Plants with delicate leaves, especially those from the Southern Hemisphere, and some bamboos, would do better in a frost with high humidity because their leaves would not be so dessicated. This is a huge generalization but you get the idea.

Even if it is below freezing, the very cold winds do keep the temeprature up compared to what it could be, because mixing of the air prevents radiational cooling. So while last night it was blowing all night and the temperature was 28-32F for many of us - if it just stopped at some point, with the arctic air in place, the temperature would drop right off, especially in sheltered valleys where radiational cooling typically brings very cold temperatures. Slopes with good air drainage and places very close to the water usually do not experience such severe lows when radiational cooling occurs. This is what may happen tonight, and certainly tomorrow night, if the wind ever dies off.

Surprisingly, I'm not seeing the temperature fall like a rock anywhere just yet. It is still too windy in most places. The South Sound, which is often the coldest, is still experiencing strong winds that are keeping the temperature up around 30.

bboy, point taken but
#1 it makes more sense to ignore the tops of the mountains since no one lives or gardens there
#2 really all you are doing is pointing out the inadequacies of the USDA zone system for our region, which I would agree with. But you could just as well say that Sunset, with only two zones for western Washington's lowlands, is oversimplified as well.
#3 if we figured everywhere was in the same zone as the land all around it, we would only have one zone.

Since if you compare the two mappings primarily the only part where they differ markedly on the local climate patterns is the Port Townsend and Olympia circles, that reinforces those two as inaccurate anomalies. The rest is mostly a matter of what naming the two systems use. Both have the area split up into bands of mountain climate and lowland climate in approximately the same general areas. As Sunset mentions the (mostly unoccupied) mountains are much colder than the (partly heavily populated) lowlands. They're having the zone numbers drop down from 4 or 5 to 1 (in most areas) expresses this difference better than the USDA's 8 to 7.

>#3 if we figured everywhere was in the same zone as the land all around it, we would only have one zone.Not all the land around, the land immediately around, as in same elevation, topography etc.

I like my argument better.

What is your argument, anyway? First you seemed to say it WAS Zone 7 near Olympia. Then you said the USDA zoning system wasn't valid.

8.9 isn't much less than 10. Putting all of the same section in one zone and this little patch in another because of an arbitrary cutoff is silly.

I don't think there is much more to say than what I said. I was just responding to your post, which you began by deviating from the topic of this current weather event to discussing climate zones.

It might not be silly to those of us that lose plants when someone a few miles away doesn't :-)

It hasn't been cold enough to damage anything here. Lowest temp. of the season I recorded this morning was -1.8 Celsius or 28.76 F. Not cold at all in my opinion. Prunus are blooming and all the Daffs are in bloom as well. I saw Forsythia in bloom today near town. Joe

Our area suffered much more wind damage than anything in Bonney Lake. Trees fell on power lines, and the power was out yesterday from about noon until 9 or 10pm. The wind caused a big photinia of mine to crash over. That actually wasn't a bad thing, because now I can replace it with a much prettier Japanese maple!

>That actually wasn't a bad thing, because now I can replace it with a much prettier Japanese maple!Unless there was a water mold or fungus in the soil that rotted the roots, such as armillaria.

"Warm" and "cold" gardens occur within the same USDA zone, USDA zones aren't that precise. Differences that might equate to Sunset 4 and Sunset 5 might perhaps correspond to USDA 8a and USDA 8b in many instances.