Frost Damage

I've been looking through the posts that many of you have made recently about the frost damage that so many of the palms sustained. We had a little bit of cold weather about a month ago and it dipped into the high 20's but we've sustained nowhere near the devastation that many of you have. I hope at least some of the palms recover.

This message was edited Jan 24, 2010 12:26 AM

This is about the extent of the damage that we sustained here in our yard. I didn't check the weather reports and we had a couple nights dip into the mid to upper 20's. These pygmy date's look a little worse for wear but the crowns are still nice and green so the damage appears to be only cosmetic. These guys made it through a terrible freeze in 2007 but it took them the whole summer to recover.

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One palm that I was worried about was my young Bismarckia but the cold has actually intensified the purple color. It's close enough to the house that the frost must not have gotten to it.

I'm surprised that either of those would have survived sub-zero (celcius) temperatures.

"Warm spots" seem to have a magical effect in just frosty conditions.
And sometimes in freezes. I looked again at my neighbor's sagos today
and one is just burned a little, and the others are burned head to toe. And
they are all in a row.

My master-gardener friend claimed I have spots which are 9b right adjacent to
8a due to just a little elevation...and it's weird...it gets much colder as I walk
around in just a 1 meter drop.

Also, a little "overhead coverage" works miracles...for a few hours around here.
I haven't seen a single pygmy date that isn't all gray within 20 miles...and they line
boulevards.

I agree about those "warm spots", or microclimates. I have them here as well. At the front of my place is warmer than at the back. Noticeable during cold, still nights. If I walk up the hill you can feel it get warmer. When it's windy, however, the temperatures seem to become more even.

Another key is the amount of time that the sub-freezing temps. occur. The nights we had frost the temp only dipped below freezing for a little while vs. several hours. In 2007 the temps that night hit 16 degrees for at least an hour. I had the pygmy's covered and they are on a slight hill so that is probably what kept them alive. According to plantfiles the Bismarckia is hardy to 20 degrees and the ones in the area that I saw after the '07 freeze did sustain some heavy tissue damage on the leaves but I didn't see any that died. It seems that many plants are hardier here in AZ than some other places in the country. I don't know what factors contribute to that (humidity?) but it seems to be the case.

That would be good to know. I know in the desert,
like in Vegas, it's harder to feel heat/cold due to the
dry air. When I lived up North I'd work outside in
my T-shirt when it was 40F. Down here that same
40F feels like 20F...especially the closer to the Gulf
one gets...the moisture is bone-chilling.

Maybe the dew point makes more condense on a plant
right before it freezes? I always thought the technique of
fungiciding the crown before a freeze kept excess moisture
off of it and made the thawing out less susceptible to tissue
damage/fungal growth.

Big chains sell Bismarckias around here for a big price, and I
always note how terrible they look toward Spring...and they
still don't mark them down.

QCHammy, I was just looking at the photos of your pygmy dates. I covered mine during our big freeze (low 20s at night for 4 nights, below freezing in the days). They look much worse than yours, but you do give me hope when you said that yours had survived a bad freeze in '07. There's still a little bit of a sick looking green here and there among the dead, brown fronds on mine. I don't plan to trim them or anything until all danger of frost has passed.

Thank you for giving me a ray of hope that they may actually survive.

My Roebellini went South in December after about a 14
hour light freeze. It was in the most sheltered place I have and
next to South-facing brick. There is a smidgen of green left.

I agree that a long freeze at 31F is far worse than and hour
at, say 25F. Freeze "warnings' are for 2+ hours here...once it's
all night bad things tend to happen.