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View Full Version : What is the coolest temperature before plant damage?


amantedelenguaje
04-16-2012, 09:19 PM
The weather as of late is like a yo-yo, up and down. The temperature here is forecasted to dip into the forties overnight a couple of times next week although daytime highs will be in the upper seventies. I want to avoid bringing in all my potted bananas if possible because I keep damaging leaves while moving them through the threshold and I'v e transported my heavy nanners many times in the past month. What is the coolest temperature that the bananas can take before damage occurs? FYI, I have several Dwarf Cavendish, Dwarf Namwah, and a couple mystery bananas that might be Misi Luki or Mysore.

steven
04-16-2012, 09:45 PM
well, from my personal experience, you should bring them in if temps dip below 50F. If your worried about possibly damaging leaves, then you might want to take into consideration that they will be damaged either way from the cold.

caliboy1994
04-16-2012, 10:04 PM
It really depends on the cultivar. Some cultivars don't get leaf damage until frost is formed while others will show leaf damage as high as the 40s. I had two mystery bananas planted in the ground over the winter, and the temps got as low as 34 degrees with no real damage. The varieties you have aren't particularly cold sensitive, so I wouldn't worry unless temps dipped below 40 degrees.

sunfish
04-16-2012, 10:25 PM
My plants are out all year 40's are no problem

caliboy1994
04-16-2012, 10:41 PM
Again, it depends on the variety. Red varieties tend to be more cold sensitive.

sunfish
04-16-2012, 10:59 PM
No problem :)

venturabananas
04-17-2012, 12:31 AM
If it's dropping down into the low 40's, I'd keep the Cavendish inside at night. High 40's probably won't be much of a problem. My Cavendish varieties look pretty sad when it gets down into the low 40's. Dwarf Namwah will be fine. If the mystery bananas are really Misi Luki and Mysore, they'll be fine, too.

caliboy1994
04-20-2012, 12:34 PM
My two mystery plants look suspiciously like Cavendish varieties, and they didn't seem to mind the winter. One of them just lost a few leaves. Now they're both bouncing right back.

venturabananas
04-20-2012, 12:49 PM
My two mystery plants look suspiciously like Cavendish varieties, and they didn't seem to mind the winter. One of them just lost a few leaves. Now they're both bouncing right back.

Some of the FHIA ones, like FHIA-1 and FHIA-18 look pretty "Cavendishy" to me when they are small, but they handle cold weather better.

Nicolas Naranja
04-20-2012, 01:38 PM
A lot also depends on how long they are exposed to the cool temperatures. There have been days during the winter in Pahokee where the temp doesn't get above 50 and the low is in the upper 30s and I have more damage then than when I would have a quick overnight dip to the same temperature. If we are talking only 4 hours below 50 I wouldn't be concerned at all.

DoctorSteve
04-20-2012, 02:27 PM
I think in zones where it is cooler dips in temperature may do more damage. Here when it gets cold enough to do damage it is at night and the low only lasts for about an hour or so. Our temps tend to drop fast and rise fast over night. In summer though it doesn't drop fast enough, for me anyway. This morning it was 75 inside at 9:45am.

I get little spots on my leaves when it gets about 40 (at night), almost complete leaf death at 32, and petioles die back below that. Oh and of course any colder pseudostem damage.

I think it depends on cultivars grown and how long you lows last.

What kind do you grow? Maybe some others who have grown them can give input.

amantedelenguaje
04-22-2012, 12:23 PM
Thanks for all your help! Tomorrow the temp is predicted to dip down to 37 degrees. I'm going to have to bring all my bananas, citrus, pineapples, and avocados inside. Additionally I'm going to have to cover tomatoes and peach trees. I guess you have to take the good with the bad if you want to be a gardener.

bananarama2
04-22-2012, 01:48 PM
In my experience, there are three mitigating factors with freezing of plant tissues. Some varieties are indeed hardier and can take a degree or two lower temperatures (desert and high mountain varieties of many plants, for example). Micro-climates within your property can be a significant difference when it comes to tolerance of lower temperatures (wind/humidity/reflected heat and light, etc). Finally, I've noted that my plants can take some fairly low 30's temps as long as there is fairly high humidity at the time. The heavy dew that will form on the plants seems to act as an insulating blanket for the plants. Reduced growth and vigor is a sometimes result however, as most plants essentially "shut off" below approximately 44 degrees. Gardening is always more of an art than a science, so your results may vary! Best regards and good luck!:08:

auburnfan28
04-22-2012, 04:24 PM
I know, 38 predicted here for monday night, 42 for tonight. I am sick of this!! My in ground bananas are finally starting to come on pretty good and here comes the cold for one final push. I know it can frost above 32 degrees, hopefully that won't happen. I think im just going to bring my potted bananas inside and roll the dice on the in ground bananas, don't really feel like covering and uncovering them.

pitangadiego
04-23-2012, 09:00 AM
What is damage? Fried leaves? Dead pseudostem? or just loss of vigor that is never recovered from, tat leads to less fruit or smaller fruit? If the latter, for many varieties, esp. in the Cavendish family, probably 50F. It also matters how long it is cold, and if it is also wet (raining). Cold and wet (above freezing) is more damaging than cold or wet by themselves. A couple nights at 38F is different than two weeks at 45F, but possibly not a damaging. Soil temp probably makes a difference, as well.

amantedelenguaje
04-23-2012, 04:49 PM
What is damage? Fried leaves? Dead pseudostem? or just loss of vigor that is never recovered from, tat leads to less fruit or smaller fruit? If the latter, for many varieties, esp. in the Cavendish family, probably 50F. It also matters how long it is cold, and if it is also wet (raining). Cold and wet (above freezing) is more damaging than cold or wet by themselves. A couple nights at 38F is different than two weeks at 45F, but possibly not a damaging. Soil temp probably makes a difference, as well.
For my purposes, I consider a dead pseudostem to be the worse case scenario. I keep my DC potted and indoors so that my plant does not have to regrow the p-stem each spring. In theory, over-wintering indoors means I will harvest bananas sooner. From Nov. 2011 to Mar. 2012, my plant was able to produce 8 new leaves indoors. Furthermore, I suspect the bell is now inside the p-stem just waiting for its moment in the sun. If the leaves are killed by frost, then more should regrow, but if the p-stem dies with the bell inside then I've nursed this banana 1.5 years for nothing. I would have to wait for my smaller DC plants to mature before I ever harvested my very first raceme of bananas.

auburnfan28
04-23-2012, 09:35 PM
@amantedelenguaje. When you move your DC back outside in the spring, does the plant have a very hard time getting used to the sun again. I purchased a DC and i plan on trying to overwinter them inside as well. I am also going to grow mine in a pot all summer. One more question, do you give your potted DC all day full sun? Thanks.

amantedelenguaje
04-24-2012, 05:25 PM
@amantedelenguaje. When you move your DC back outside in the spring, does the plant have a very hard time getting used to the sun again. I purchased a DC and i plan on trying to overwinter them inside as well. I am also going to grow mine in a pot all summer. One more question, do you give your potted DC all day full sun? Thanks.
For the first couple of weeks that my DC is outside, the leaves tend to scorch around the edges where the tissue seems a bit more delicate. Although I offer it as much shade as possible for its first few weeks outside, I still get some leaf damage. Pretty soon, my DC gets use to being outside and the new leaves do not burn. The problem I have had over the past 1.5 months is that every time I put my DC outside for a week or two, another unexpected cold snap occurs, so I bring them back inside. While inside the leaves are exposed to low light, so when I return them to the outdoors, the leaf-scorch cycle begins again.http://1.bp.blogspot.com/-DZN9VsUM9f8/T5cixCtvUDI/AAAAAAAABM0/nlE8qMngyOE/s1600/P4240050%2B%2528Medium%2529.JPGhttp://3.bp.blogspot.com/-ultnz-R_WD8/T5ciw_1SttI/AAAAAAAABMk/-P4AGK-OPt0/s1600/P4240048%2B%2528Medium%2529.JPG

bananarama2
04-25-2012, 02:01 AM
In my most humble opinion, I'd like to suggest the symptoms your plant is exhibiting might be moisture related rather than from too much sun. Although the leaf margins tend to be tender, damage like your pictures show has always been because of lack of sufficient moisture in my garden. Any "scorching" I've experienced is more akin to sunburn, appearing on the surface of the leaves, when I haven't hardened the plants off sufficiently. Bananas are very sensitive to moisture loss........my two-bits worth!:08:

amantedelenguaje
04-25-2012, 10:07 PM
In my most humble opinion, I'd like to suggest the symptoms your plant is exhibiting might be moisture related rather than from too much sun. Although the leaf margins tend to be tender, damage like your pictures show has always been because of lack of sufficient moisture in my garden. Any "scorching" I've experienced is more akin to sunburn, appearing on the surface of the leaves, when I haven't hardened the plants off sufficiently. Bananas are very sensitive to moisture loss........my two-bits worth!:08:
Thanks for your very kind message. It brought a smile to my face. I respect your "humble opinion." I am no expert, so I could be wrong. Here are the facts that I have.

1. The leaves don't burn and turn crispy around the edges except when I first take my plants outside. The leaves were not brown when over-wintering.
2. I check the soil moisture levels in the plants daily with a moisture meter. If the plants are too dry, I water them. If they are wet, I leave them alone.
3. When I put my bananas outdoors for the spring/summer, I increase my watering schedule. The large plant in the picture gets watered everyday in the morning, and if the day is particularly hot, in the evening too.


This is why I feel that the burning around the edges has something to do with being exposed to sunlight after being over-wintered indoors. The crispy edges may have something to do with excessive transpiration, but I have not a clue.

By the way, please look at the large leaf emerging in the background. Notice that it is perfectly fine with no browning around the edges. Also notice that the plant is indoors in the picture due to another cold snap. The plant has been inside for about 4 days. http://4.bp.blogspot.com/-KDHuLBe8EIA/T5jAAdyAe7I/AAAAAAAABOQ/v7hpysreYPE/s1600/P4240050%2B%2528Medium%2529.JPG
Today, the temperature warmed up again, so I put it outside this morning, now look at the leaf in the background. I tried to photograph the plant from the same angle. Sorry that it is night time. I work. If the plant looks a little funny, it is because it rained earlier.
http://1.bp.blogspot.com/-5r1ZxaLI5NQ/T5jAApyk5iI/AAAAAAAABOc/aHqcxbw0RmY/s1600/P4250067%2B%2528Medium%2529.JPG The leaf that was perfectly beautiful this morning is now burnt around the edges.
http://2.bp.blogspot.com/-va9YeuSNk4A/T5jABCMnXbI/AAAAAAAABOo/gO1nw9jytAQ/s1600/P4250069%2B%2528Medium%2529.JPG

bananarama2
04-26-2012, 02:01 AM
Hi Tammy....I'm no expert either, so we will get along nicely! LOL
I'll still stick by my first thoughts on the browning/scorching of leaf margins, only because that's the only problem I've encountered that produced similar results. As before, I'm always careful with tender tropicals to allow them an acclimatization period of at least a week in a spot protected from direct sun, wind and even hard rain. The relative humidity varies greatly around the country, and plants will sometimes not be able to maintain lush growth at points furthest from the roots, which would include those leaf margins. I'm on Vancouver Island, which has a fairly humid climate (classed as temperate rainforest), so may be just lucky to not see those symptoms on my plants. Again, ordinarily, plants will not actively grow at temperatures around the 40 degree mark, so the root system won't be active either, and "wind scorch" could easily occur. It is rhetorical just the same, since the plants are certainly not as attractive as you'd like because of the damaged edges. The fact that you have to lug plants back and forth because of record low temperatures can't be much fun either! We're stuck with temperatures below the norm here for the last couple of months as well, and there's a lot of grumpy gardeners about as a result. I hope you find the answer to your problem soon and spring/summer temperatures bless us all! P.S. Am I safe in assuming you are in the American southeast, which has been experiencing some oddly cool temperatures lately? :08:

amantedelenguaje
04-26-2012, 05:58 AM
I'm in North Carolina.

venturabananas
04-26-2012, 09:55 AM
I'm no expert either, but the symptoms sure look like those you'd expect to see on a plant that hasn't bee "hardened off" before being placed inside. If the plant has been inside all winter, its tissues won't be able to handle full sun, full wind, etc., as Rik mentioned. I'd put it outside in dappled shade under the canopy of a tree for a week or so before putting in a fully exposed spot. Alternately, you can put it in full sun, and the existing leaves won't be totally happy, but the new ones that emerge will be fine.

TommyMacLuckie
04-29-2012, 03:20 PM
There is no need to bring anything inside for 36F. They'll be fine - all of the plants. I leave my plants out even if it's going down to 32F because one hour of 32F is not going to do any damage and it takes at least 4 hours at 32 for anything to freeze. None of my plants, regardless of what they are tropical wise, have ever suffered any damage below 42F or above 32F.

I know there are some tropicals that don't like to be below 42F but I don't have any of those.

However, if there is any kind of a breeze or it's windy and it's in the mid-30s there is a decent chance of wind burn or a major drying out of the leaves/fronds so watering before sundown will help.