Brug leaves hit by frost, but hardness zone says...

USDA Zone 9a: to -6.6° C (20° F)
USDA Zone 9b: to -3.8° C (25° F)
USDA Zone 10a: to -1.1° C (30° F)
USDA Zone 10b: to 1.7° C (35° F)

Although I'm in zone 8a, the recent cold snap didn't hit here below 20 degrees. It did get to 28 and 30 for a few nights. According to the above list, does this list of low degrees giving 20 f to 35 f indicate the cold tolerance? I'm trying to tell myself that my drooping leaves (wet-look) on my just planted rooted cuttings well make it. According to GEORGIAWEATHER.net, while the cold temps did drop, soil 2 in below ground was in the 60's range.

Can anyone explain the hardness listings to me and have experience with drooping leaves coming back or growing new leaves when bit my frost?

Deborah

Deborah, the temperatures listed for each of those zone are the same as those listed by the USDA for their map. Those are minimum temperatures that that zone receives. Were you plants covered? In the ground? I have had a few singed by frost, but only for a few hours. The leaves get somewhat transparent and droopy. Those are toast. If the stalks survive your plant will put out new leaves. If the stems were also affected, depending on the damage, some of the stem will survive. If the soil did remain warm, I would assume that you will get new growth from the root stems. Go easy on the watering until new growth shows up.
Veronica

Deborah,, I covered most of mine, but had a few that were not covered. Leaves were droopy, but I think rest of plant will be fine. It got down to about 29 here, so I bet yours will come back.. may take a little longer.. Will keep a check on. Going to uncover everything,,,AGAIN tomorrow. whew..
Elaine (in Lizella)

Veronica and Elaine, thank you both for replying. Whew! Y'all are the bearer of good news.
I had planted these rooted cuttings in the ground a couple of weeks before the freezing temp came Easter weekend. Today I snipped the dropping leaves off and the stems were a perfect green color. Hopefully that's a good sign that they will snap back with new growth. I'm glad I read the advice about going easy on the watering. My first instinct would be to go out and water'em. I didn't though. We are expecting rain Tuesday and Wed. Hope it's not a flood. Elaine, I covered mine a day too late. I should have covered them Friday night, instead of waiting Sunday. Oh well, I'm always a day late and a dollar short.

The usual hardiness recommendations are for plants with fully established root systems, so your cuttings could be much more tender than a typical plant. The minimum temp ratings are also usually just for root-hardiness, where the top of the plant dies down & comes back from the root (which a new start usually can't do).
I agree with Veronica about limiting water. That's another thing that can limit your hardiness -- lack of winter drainage. Ground that stays wet in freezing temps can rob you of 10, 15, or more degrees of hardiness.
I hope it comes back! :^)
- Tom

Thanks Tom. I was wondering about why the limiting watering. Thinking to myself hat it must cause crown rot of some sort. Now I see that keeping the ground too wet during freezing temps lowers the temp of the soil as well. That helps me a great deal. Luckily, my soil was dry. The soil temp. 2 in below was actually in the 60's after reviewing my Ga weather site. That higher soil temp while the air temp was below freezing may be my saving grace.

Deborah, the reason I advised limiting water is that leafless Brugs don't utilize that much water. If the soil remains wet for too long, the roots have a tendency to rot. In fact, the recommendation is to water your plants before a freeze:

I'm learning something new every day! Thanks for that quote. I'm keeping it for reference. Just heard on the weather channel that the Ga. farmers who wet their strawberries before the recent freeze did not suffer much loss but those who didn't use water beforehand lost their crop. In this case, the water on the unripe fruit turned to ice and acted as an insulator.

The article was referring to wetting the soil. Overhead watering would have to coat all surfaces of the plants to form a thick layer of ice. That means watering for as long as it stays at or below 32ºF. LSU doesn't recommend doing that because, besides being expensive and impractical, if everyone did that the town's water pressure would drop down to practically nothing causing more problems.

But I must say that it does work. In February, we had a hard freeze that lasted over 2 days. Fortunately, it rained the entire time. The wind was strong enough to expose all surfaces of the plants. I was amazed at the plants that survived without much damage. With some, the combination of being under the eeves and having a thick coat of ice, there was almost no damage.

Hi Betty, that was good info thank you. :^) But it only works short term though, and only if you have good drainage. If you try to sustain that for any length of time at all you'll rot the roots in the cold. I didn't say that watering lowers the soil temperature, only that you will lose 10, 15, or more degrees of hardiness if the soil stays wet in freezing temps. That's due to the increased likelyhood of rot with insufficient oxygen getting to the root zone in colder weather.
- Tom

Tom,
If I understand correctly, what you are saying is that a plant under stress (insufficient oxygen or dead roots) is not as hardy. Yes, that is true.

I would not have made that part of my statements above because we usually make assumptions based on what we are used to. You must live in an area that gets lots of rain. I've lived most of my life in the San Francisco Bay Area where on the average we'd get 13 - 15 inches of rain a year. Here in central Texas, we get about 37" of rain spread throughout the year, but the soil is very sandy. Thanks for the reminder.
Veronica

I covered mine with a kiddie pool. They survived the 20 odd degree cold
snap and frost, and are now coming back from the roots.

Yes! :-)