Freeze warning!

Ack, there's a freeze warning in my area for this evening!  Actually, it covers a big area; across Ohio, the northern parts of PA, and all of western NY (and probably a lot more that my map doesn't cover). 

Anyhow, this is the first freeze/frost warning we've had all spring, can you believe that?  This close to my last frost date (1.5 weeks away), I'm totally not prepared.  Not only that, but the unseasonably warm weather we've been having for the last month or so has gotten my outside plants ahead of themselves, so now I'm really afraid I'm going to wake up to a bunch of damage tomorrow.

So I was wondering if anyone has any advice on how to protect plants during a freeze, and which plants I should focus most on.  Here's what I've got growing outside:

Onions well established
Cabbage just transplanted
Cos lettuce well established and getting big
Potatoes just peeking out of the MM
Radish seedlings
Beet seedlings
Carrot seedlings
Peas that are about 6 inches tall
Tomatoes inside wall-o-waters
Summer squash inside wall-o-waters
Garlic

Non-sfg plants:
Blueberry bushes just starting to bloom
Dwarf apple trees starting to bloom
Strawberries starting to bloom
Raspberries starting to leaf out

I'm off to do a bunch of searching on Google.  I'll report back with any info I can find.

Way up here in Ottawa, Ontario, Canada we are expecting 3 degrees Celsius overnight and there is a frost warning.  After tonight the overnight temps move up to 9, 10, 15 and 16 for the following four nights.

Ok, what I've found so far is that, first, the damage that might happen during a freeze depends heavily on what temp it's going to be and for how long. Here's some info I found:

Down to 28 degrees for a couple of hours: light frost, light freeze; Usually only harms very tender plants.  Ice forms on the outside of plants.

25-28 degrees for several hours: hard frost, killing frost, moderate freeze; Damages foliage and blossoms.  Ice forms inside the plant, causing plant cells to burst.  Will kill back root hardy perennials and damage crops.

Below 25 for several hours: severe frost; Causes damage to many plants, mostly through desiccation (drying).


The predicted temps for my area are in the low 30s, so thank goodness it's not going to be that bad. But I'm still going to take precautions. Here's the info on specific plants I found.

Peas: are fine down to 28 degrees. Receive damage between 20 and 28 degrees. If covered by snow, can survive down to 10 degrees.

Onions: are fine down to 20 degrees.

Cabbage: Can handle temps down to 20 degrees, unless they're used to growing in much warmer temps. Also, sudden low temps can cause buttoning.

Radish: Can survive to 26 degrees.

Lettuce: Full grown plants can handle temps of 25 degrees for up to four hours, and warmer temps for longer periods. Seedlings can handle temps as low as 22 degrees.

Potatoes: can handle temps between 29 and 32 degrees with little damage.

Garlic: I can't find any information on this.

Beets: Can tolerate down to 30 degrees, seedlings are hardier.

Carrots: can survive down to 20 degrees.

Blueberries: blossoms that are fully opened are damaged at 27 degrees, whereas unopened blossoms can manage much colder temps, as low as 20 degrees. Blueberry fruit begin to get damage at 28 degrees.

Apples: Fully open blossoms can handle temps of 28 degrees for a short period.

Strawberries: fully open blossoms start receiving damage at 28 degrees, but unopened blossoms can take much colder temps, down to 22 degrees.

Raspberries: couldn't find much info on these, but one website said that they're a tender plant and begin receiving damage at 32 degrees.

Ok, so here's what I plan on doing in my garden.  I think after dinner, about 6pm when it reaches the high for the day (52), I'm going to go out and start getting everything ready for the night. 

I'm going to put some heavy pots over my cabbage transplants.  I wouldn't worry about them normally, but it seems like every year I grow them they get button heads (really tiny heads) because of a cold snap, and that's why I planted them later this year than I usually do.  

I'm going to put the cover back over my lettuce, which will be easy because I left the hoops in the ground after taking the cover off recently.

I think the carrots, onions, peas, beets, radishes, and garlic should be just fine, so I'm going to leave them be.

I'm going to cover the tops of my potatoes (just an inch tall or so) with MM.

I'm going to tie closed whatever wall-o-waters that I can.  Some of the tomatoes are popping out the tops, so I'm going to try covering those with a sheet.

I'm going to put tarps over my apple trees.  They're two year old mini dwarf trees, so they're pretty small.  They also already have a cage around them, so it will create a little wall of protection. 

I'm going to cover the blueberry bushes that are blooming with sheets, which thankfully are the small ones and not the 5 foot tall ones.

I'm going to put a sheet over my strawberry bed, and also drape one over my raspberry canes. 

And finally, I'm going to bring all of my potted plants into the garage, where it should stay at least above freezing. 

Wish me luck!

Wow.  Bummer.  But it sounds like a GREAT plan you have there. I'm sure it will work and everything will be fine.  I remember doing that one year but now...everything just gets snowed & hailed on. 
 
I hope it's not coming here to New England.  I know we are heading down in temp tonight and tomorrow night but I think it's only into the 40's for the Cape.  I was hoping to plant out my summer veggies this Friday, a week ahead of the Memorial Day schedule, but maybe I'll rethink that.

Anyway, good luck!  Let us know how your garden fares.
CC

I've tried covering smallish plants, such as tomatoes , with pillowcases in the greenhouse.  Outdoors, they can be anchored with small rocks, such as river rock.

I was out last night just before dusk to wrap my dwarf stock fruit trees up  like white ghosts as the apple trees are in part pollinated bloom . Any frost would , " Nip these in the bud " resulting in few if any apples later this year .
  I'm looking at online forecasts for tonight's temps . Anything of 3 oC or less and they will get wrapped up again

3 oC  is the temp at which water starts to turn to ice  , 0 oC is when the ice will be solidified

trolleydriver wrote:Way up here in Ottawa, Ontario, Canada we are expecting 3 degrees Celsius overnight and there is a frost warning.  After tonight the overnight temps move up to 9, 10, 15 and 16 for the following four nights.

Glad you are aware of it, trolleydriver.  I should have been looking out for it myself.

Thanks for all the replies, guys.  I meant to post this pic last night, but by the time I was finished putting all the covers over my plants, my back had started to spasm and all I wanted to do was lay in bed   BUT I got it all done!



It was 32 degrees when I woke up at 6:30, so I waited until about 8 to take all the covers off.  By then it was 39 degrees.  And it looks like everything made it!  It was actually pleasantly warm inside the apple tree tarps.  I'll go out later to see if I see any damage, but it all looked good to me.

The weather site says we didn't actually get below freezing here (+0.6°C, or about 33°F) there was a heavy frost on the cars and the lawn. Fortunately I don't have anything I the ground yet, including my Mel's Mix.

Eain all long weekend

The temperatures reported by the weather geeks are often off by as much as 10 degrees F (sometimes even more) from what my outdoor thermometer reports.  I cover my plants if the forecast low is 42 deg F (5.6 deg C) or lower, and on a number of occasions, I was very glad I did!

Agreed! My 99 cent / twenty year old thermometer said we were just below freezing. That's one reason to be wary of "Last frost dates". We shouldn't have had frost according to conventional wisdom. The lake usually protects us from the last frost (I'm exactly 1 kilometer or about 0.6 miles from the beach). But as I said elsewhere, it was a huge slushy to weeks ago; I'd guess the water is still not warmer than 40°F.

I'm waiting for the lilacs to bloom.

(Oh yeah, typo alert: that should have said RAIN all weekend. Now maybe not!)