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Freeze warning for tonight (Sunday)

Posted by Pagancat Phoenix, AZ (My Page) on
Sun, Nov 27, 05 at 16:48

From the NOAA site:

WEST CENTRAL DESERTS-NORTHWEST MARICOPA COUNTY-
GREATER PHOENIX AREA-SOUTHWEST DESERTS-SOUTHWEST MARICOPA COUNTY-
NORTHWEST AND NORTH CENTRAL PINAL COUNTY-
INCLUDING THE CITIES OF...BOUSE...QUARTZSITE...SALOME..
LAKE PLEASANT...MORRISTOWN...NEW RIVER...TONOPAH...BUCKEYE..
WICKENBURG...CAREFREE...CAVE CREEK...CHANDLER...FOUNTAIN HILLS..
GILBERT...GLENDALE...MESA...PEORIA...PHOENIX...SCOTTSDALE..
SUN CITY...TEMPE...DATELAND...TACNA...WELLTON...GILA BEND..
APACHE JUNCTION...CASA GRANDE...COOLIDGE...FLORENCE
205 PM MST SUN NOV 27 2005

...FREEZE WARNING IN EFFECT FROM 11 PM THIS EVENING TO 8 AM MST
MONDAY..

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A FREEZE
WARNING...WHICH IS IN EFFECT FROM 11 PM THIS EVENING TO 8 AM MST
MONDAY.

PORTIONS OF MARICOPA...PINAL...LA PAZ...AND YUMA COUNTIES..
INCLUDING THE GREATER PHOENIX AREA SHOULD SEE THEIR FIRST FREEZE OF
THE SEASON TONIGHT. OVERNIGHT LOWS AT SKY HARBOR AIRPORT ARE EXPECTED
TO REACH 37. ..WITH OUTLYING VALLEY AREAS LOWERING TO THE UPPER 20S TO
NEAR 30.....

A FREEZE WARNING MEANS SUB-FREEZING TEMPERATURES ARE IMMINENT OR
HIGHLY LIKELY. THESE CONDITIONS MAY DESTROY OR DAMAGE CROPS AND
OTHER SENSITIVE VEGETATION.

Good luck!


Follow-Up Postings:

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RE: Freeze warning for tonight (Sunday)

Yikes! Glad I have my various assortment of colorful sheets, pillowcases and old table cloths clean and ready to go!

Thanks for the update!

Susie


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RE: Freeze warning for tonight (Sunday)

  • Posted by gem1 w.phx 9 (My Page) on
    Sun, Nov 27, 05 at 17:26

Is there a rule of thumb as to what type of plants can stay out and exposed, and what should be moved to a protected area?


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RE: Freeze warning for tonight (Sunday)

Bougainvillea and Lantana are very frost sensitive as are all succulents.


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RE: Freeze warning for tonight (Sunday)

Thank you for the weather report. I was just outside to check the temp and its 51 on my patio.... 4:30ish. 7th st and T-Bird. I'm COLD! I'm covering my succulents and bundling up my potted petunia's. People who don't understand the desert can't imagine it can get so cold. Stay toasty!


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RE: Freeze warning for tonight (Sunday)

I was up at 11:00 pm covering plants after watching the news last night. Glad others understand I am sure everyone driving by thought I was a little crazy! Going to the store after work for more burlap! Any ideas on covering trees? We planted quite a few new ones recently.


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RE: Freeze warning for tonight (Sunday)

oh, now you tell me! LOL i just got back into tucson around 6:50a this morning. heard about the freeze warning on my way down from phoenix. sheesh!

i have a question. does covering your plants really help during a freeze warning if you don't provide any heat under the covering? i thought that covering the plants only protected against frost. there is a difference between a freeze and frost warnings, right? 32 degrees outside of the covering and 32 degrees under the covering are still the same, right? just curious...

detrick


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RE: Freeze warning for tonight (Sunday)

Detrick, I think the frost laying on the leaves is the real problem. Of course freezing isn't much fun either Annoyed And Disappointed
String Of Lights


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RE: Freeze warning for tonight (Sunday)

I don't think we made it down to freezing in Chandler. I checked my thermo at 4AM this morning and it said 37 degrees. I brought all the plants I was worried about up close to the house, under the eaves. They generally seem to do fine there. Even when I cover my hibiscus with a sheet the freeze back, but they always come back in the spring...so don't worry about them too much.

Easy


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RE: Freeze warning for tonight (Sunday)

Year before last we were out of town when that nasty frost hit between Christmas and New Years- down to 18 degrees or something awful like that. I'd covered a lot of plants, and the extent of damage was directly related to how heavy the cover was. I covered a couple with that thin sheet foam that's used for packing material, and those plants were about the only covered ones that didn't have some sort of frost damage, not even a slight amount. The covers were on for the 3 days I was out of town, and I don't recommend it but it can be done occasionally. Anyway, yes, it does make a difference. Especially if you have covers that insulate well and put them on before it starts cooling off for the evening, but every little bit helps.


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RE: Freeze warning for tonight (Sunday)

D, the earth is typically a little warmer than the air, just a mass cooling slower than the air. But GT is correct, as I remember - it's the frost that really causes the most damage. The freezing causes burst cells (remember, water expands when it first freezes - something I've never understood, but....)

So, what confuses me, why is it advised to water the day prior to a frost? Anyone know the actual reason? Perhaps something about evaporation?


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RE: Freeze warning for tonight (Sunday)

My understanding is that, to be really effective, the covering cloth is not supposed to touch the plant. Disallows cloth freezing ON the plant. Also, my personal experience with snaps, for instance, is that if you let them freeze, sort of melt down, then just treat them as if nothing happened, they come back MORE than beautiful and plentiful.


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RE: Freeze warning for tonight (Sunday)

I believe that as the water cools down it emits heat, which is helpful in keeping the temperature 'slightly' warmer. A degree or two can make all the difference in the world....

Susie


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RE: Freeze warning for tonight (Sunday)

It is interesting about watering before a freeze. I have heard two reasons, first one is to be sure the plant is not already stressed before the cold hits. The other thing is that water is warmer than the air, and releases heat. I also place buckets of water around plants when a freeze is predicted. The water releases heat as it cools. Put a covering on, and it is like using lights.


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RE: Freeze warning for tonight (Sunday)

You can use C-9 or C-7 Christmas lights strung along the ground right next to the plants you want to protect if you are concerned about them freezing. Covering them keeps the frost off the plants and on the cover itself. If your cover is touching the plants, it's possible that that portion that is touching will still convey the frost to the plant, anyway. Besides the plants already noted, honeysuckles and any plants with larger, thicker leaves are susceptible to frost damage. We have been fortunate so far that the temps are not going too terribly low - at least not where I live - so that the frosts are not deep frosts which can be particularly damaging to sensitive plants. I do not cover any of my cacti, I also don't cover my miniature rose vines and haven't been covering any of my vines. So far so good - I'm just hopeful that temps won't dip into the 20's - then I will be stringing my C-7 Christmas lights along the most sensitive plants to keep them warm enough to keep from frost damaage.


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RE: Freeze warning for tonight (Sunday)

Plants are very ineffective at taking up water when it's very cold. Watering before a freeze period is important and sometimes essential for some container plants depending on how long the freeze may be.

It also helps create a moist/humid environment (especially under covers) which is better for most plants than the dry air that tends to come with a cold snap.

The two combine to create a turgid plant that can better survive the cold snap and provide a less extreme environment to do it in. It's all about keeping the plant on a slow/steady path to warm-cold-warm-etc. more than it is about making sure the plant isn't cold.

During this time if high winds are a concern you really need to keep an eye on anything tender or in containers. The uptake of water is slowed during the cold period to the point where some plants can dry out pretty quickly.

BTW, if you see frost on your plants...leave it alone. It may damage your plant, but removing it (especially with water) will do more damage to most plants because of the sudden temperature change. That one is just a general guideline, though.


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clarification...

"Watering before a freeze period is important [for most all plants] and sometimes essential for some container plants depending on how long the freeze may be."


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RE: Freeze warning for tonight (Sunday)

For benb1: on the Christmas lights, what type do you use? The opaque old fashioned ones or the newer LED ones? I don't have any of the older kind but I actually like those better and they also seem to put out more heat.


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RE: Freeze warning for tonight (Sunday)

The newer LED ones won't supply the heat the traditional bulbs use. It's the heat you're going for in that method.

Of slight note...a lot of those string lights are coated with lead (for some fire safety purpose) so you might want to wash your hands after stringing them and if they bump up against anything edible you might want to wash them well, too. It's a minor thing, but it exists.


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RE: Freeze warning for tonight (Sunday)

nc-crn - great, thank you for the info! I had seen the hazard warning on my LED lights, too - crazy. I really like the old school lights we had on our house growing up, so it'll be fun to buy those again.

If anyone listens to Rosie on the House on KTAR 92.3FM on Saturday mornings, they have mentioned several times that you can also wrap your ground mounted heat pump with Christmas tree lights to keep the air warmer that is being pulled in. Obviously be very careful when setting this up! But I wrapped mine and no problems - just need to get the older lights. They also have a gardening hour their first hour from 8-9am, but I work middle/PM shift hours and I'm not up that early!


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