down to 40 degrees will my tropical hibiscus be ok?

Kansas City (Joyce), MO(Zone 5a)

How much cold can they take?

Thanks
Joyce

Norwalk, IA(Zone 5b)

I'm in Des moines area and mid 40's overnight won't hurt them. Now daytime temps in the 40's are another story.if they are in pots slide em under a dense tree or overhang on the south side of the house for a few days.

:-) Kyle

Kansas City (Joyce), MO(Zone 5a)

Thank you so much, I was not looking forward to dragging stuff in this late at night. I just got home from a trip and found out it is suppose to dip to the high 40's.

Santa Rosa, CA

I have seen them flowering here in northern ca. at 35. High 40's is no problem at all. They just won't grow as fast. Hibs need to be above 58 to keep growing.

David

Kansas City (Joyce), MO(Zone 5a)

Thank you all. We are suppose to go back up in temperature but then again one night go back to high 40's. I just want to wait til the weekend with work and all that stuff.

Joyce

Alvin, TX(Zone 9a)

Wow, you guys are making me REALLY ENVIOUS!!!!!!! It's in the mid 90s here, and feels like 110!!

Bluffton, SC(Zone 9a)

95 @ 5:00 here

(Zone 9a)

85 at almost 8. 40 degree nights??? Can you just imagine............. maybe in November.

Chariton, IA(Zone 5b)

This is what my email forecast said today: It will be cold tonight. Lows will hit the lower 40s. There will be a chance for light patchy frost in northern Iowa.

Right now it is 67. Fall is in the air.

San Bernardino, CA(Zone 8b)

Wow Brugie, sounds lovely! It's 6:15 p.m. and still 99 degrees - yuck! I am SO anxious for fall to arrive.

Eau Claire, WI(Zone 4a)

If you like lower forties how about this:

FROST ADVISORY

:(

Covered up my hardy hibiscus and my morning glories and started the count... (Third time to cover things is seldom worth it.)

Alvin, TX(Zone 9a)

Brugie - I think you and I need to exchange climates!! I'm green with envy!!

Desoto, TX(Zone 8a)

Have been dragging a huge planting in and out the last 3 winters. It is actually two plants that are accidentally entwined. One is single yellow and the other double red...sorry I am one of those doesn't know what I have because I inherited them from my mother......anyway....had them planted in the ground this year and they are almost 6 feet tall and 3 feet around. Now I'm worried.

Thumbnail by LouC
Alvin, TX(Zone 9a)

Have you guys ever heard of wrapping them in Christmas lights to keep them warm at night? Someone else on here (the Brug forum, I think) was talking about doing that to save theirs during frosts and cold nights. ?? Just an idea.

Buffalo, TX(Zone 8b)

I just googled wrap plants in Christmas lights for freeze protection and this great link was provided. I don't know how to make hyperlinks, so you will have to copy and paste it until someone tells me the html that is needed. I used to know it, but I have the "sometimers disease" and don't remember.


http://www.lsuagcenter.com/en/lawn_garden/home_gardening/landscaping/Cold+Protection+in+the+Landscape.htm

Charlene

Buffalo, TX(Zone 8b)

Well it does the html for you! Wow no thinking needed. However the link doesn't work, so I'll try it again.
http://www.lsuagcenter.com/en/our_offices/parishes/Tangipahoa/Features/Horticulture/benjamin_journal/Tender+and+Hardy+Plants.htm

Buffalo, TX(Zone 8b)

I give, it just doesn't want to work for me. Haven't a clue why. But here is the article. I thought it was worth the space it takes. Hope you don't mind.

Scroll down to cover to learn about the Christmas lights if you are interested.

Cold Protection in the Landscape
If you look around at some of our landscapes, particularly in south Louisiana, you would think we live in the tropics. Indeed, some winters the temperature never does dip much below the mid to upper twenties allowing tropicals to survive.


Despite the overall relative mildness of our winters, severe freezes do occur, and they can be devastating to tropical plants growing in our landscapes. All it takes is one night of temperatures in the mid to low twenties to severely damage or kill many tropicals.


Despite the possibility of sometimes severe freezes, Louisiana gardeners still cling to the use of tropical plants in the landscape. I wouldn’t give mine up either. Nothing else performs as well as tropical plants during the intense heat of summer. But it does mean that we sometimes need to help these plants to survive when freezes do occur.


HARDY VS TENDER

Two terms are used when it comes to the ability of a plant to tolerate cold. If a plant will endure temperatures 32°or below with no damage, it is termed hardy. There are degrees of hardiness. A plant that will tolerate a temperature of 15° is hardier than one that will be killed at temperatures below 25°. Our commonly used landscape plants, including trees, shrubs, ground covers, lawns and vines, are hardy to at least 10 or 15 degrees and will not be damaged by typical winter weather.


The term tender refers to plants that are killed or severely damaged by temperatures of 32° or below. Surprisingly, many tropical plants are more cold tolerant than we give them credit for, and will tolerate light freezes where the temperatures dip briefly below freezing. But you do run a risk leaving them out or not covering them on nights when even light freezes occur. Many tropicals may survive a hard freeze (temperatures in the mid twenties and below freezing temperatures lasting most of the night) by coming back from their lower trunk, crown, roots or below ground parts (tubers, bulbs, rhizomes). Since the ground in south Louisiana does not freeze, plant parts at or below the soil surface often survive.

Always look at the actual temperature predicted not the wind chill. Plants do not feel wind chill. Cold, but above freezing, windy weather can cause leaf damage to some tropicals, but this is due to the dessication or drying out of the foliage tissue (often called wind burn) not cold damage.


TYPES OF FREEZES

When freezes do come, they can be characterized as radiational or advective. Radiational freezes or frosts occur on calm, clear nights when heat radiates from surfaces or objects into the environment. These freezes are generally considered light and primarily damage the foliage of tropicals. Plant damage from a radiational freeze can be minimized by reducing radiant heat loss from plant and soil surfaces.


Advective freezes occur when cold air masses move down from northern regions causing a drastic drop in temperature. Windy conditions are normal during advective freezes. Although radiant heat loss also occurs during an advective freeze, the conditions are quite different from a radiational freeze. The temperatures tend to be much lower and are liable to last longer during advective freezes, and protecting tropicals is more difficult.


FACTORS INFLUENCING COLD INJURY

The most important factors in how much damage a plant receives from cold are how hardy it is and how cold it gets. There are, however, a surprising number of other factors that can play a big role in how much cold injury occurs.


Make sure good care is given to your landscape during the summer growing season. Plants, even hardy ones, doing poorly or in low vigor are more susceptible to cold damage. Pruning and fertilizing hardy trees, shrubs and ground covers should be avoided after September, as this can stimulate late growth which is not as cold hardy and may lead to freeze injury.


A sudden drop to below freezing temperatures from a period of relatively mild weather, may cause damage even to hardy plants that might otherwise have suffered little or no damage. A gradual decrease in temperature over a period of time will harden off plants allowing them to withstand freezing temperatures better. This is not true for especially tender plants, as they will not tolerate freezing temperatures regardless of the preceding temperatures.


The longer below freezing temperature persist, the more likely damage is to occur. This is because as time goes by, heat stored in plants, soil, walls, etc. that initially moderates temperatures around the plant is lost. Freezes that last 8 hours or more are particularly damaging to tender plants.


Finally, where a tropical plant is located in the landscape can make a big difference in how much damage occurs. The careful placement of tender or less hardy plants in sheltered areas that block cold north winds and trap the heat of the sun can help them survive freezes. Planting in areas covered with overhangs or tree canopies will also help to minimize cold damage.


WHAT TO DO BEFORE A FREEZE


WATER

Thoroughly watering landscape plants before a freeze may reduce the degree of freeze damage. Many times cold weather is accompanied by strong, dry winds. These winds may cause damage by drying plants out and watering helps to prevent this. Wetting the foliage of plants before a freeze does not, however, provide any cold protection. A well-watered soil will also absorb more solar radiation than dry soil, and will re-radiate the heat during the night.


MOVE INSIDE

Move all tender plants in containers and hanging baskets into buildings where the temperature will stay above freezing. If this is not possible, group all container plants in a protected area (like the inside corner of a covered patio) and cover them with plastic. If plants are kept inside for extended periods, make sure they receive as much light as possible.


MULCH

For plants growing in the ground, mulches can help protect them. Use a loose, dry material such as pine straw or leaves. You should be aware that mulches will only protect what they cover. Mulch at the base of a bird-of-paradise will help the roots, but will provide no added protection to the leaves. Mulches, then, are best used to protect below ground parts, crowns or may be used to completely cover low growing plants to a depth of four inches. Leave complete cover on no more than three or four days.


COVER

If they are not too large, individual plants can be protected by covering them with various sized cardboard or Styrofoam boxes.


Larger plants can be protected by creating a simple structure and covering it with sheets, quilts or plastic. The structure holds the covering off the foliage preventing branch breakage and improving cold protection. It need be nothing more elaborate than three stakes slightly taller than the plant driven into the ground. The cover should extend to the ground and be sealed with soil, stones or bricks. Plastic covers should be vented or removed on sunny, warm days.


The covers will work best for radiational freezes by preventing or blocking heat loss. The extreme, prolonged cold that occurs during advective freezes is not so easily dealt with. Many plants will still die even with protection. This can be helped by providing a heat source under the covering. A safe, easy way to do this is to generously wrap or drape the plant with small outdoor Christmas lights. The lights provide heat but do not get hot enough to burn the plant or cover. Please be careful and use only outdoor extension cords and sockets.


If necessary, you may prune back a large plant, like a hibiscus, to make its size more practical to cover. For trees, such as citrus, that are too large to cover, you may at least want to wrap the trunk with an insulating material such as foam rubber or blankets. Even if the top dies, you may be able to regrow the tree from the surviving trunk.


If you are growing vegetables, harvest any broccoli, cauliflower, fava beans or peas that are ready. Freezing temperatures will not hurt the plants, but can damage the heads, pods and flowers. Also, any citrus fruit should be harvested from the tree prior to a hard freeze.


WHAT TO DO AFTER A FREEZE

After a freeze is over, check the water needs of plants in containers and in the ground. Unless you are keeping them inside for the rest of the winter, move container plants back to their spots outside.


For plants that you covered, remove or vent clear plastic covers on plants to prevent excessive heat buildup if the next day is sunny and mild. You do not need to completely remove the cover if it will freeze again the next night. You may leave plants covered with blankets or sheets for several days without harming them, but eventually the covers will need to be removed so they can get light.


Do not prune anything for several days after a freeze. It often takes several days for all of the damage to become evident.


Damaged growth on herbaceous or nonwoody plants, such as cannas, elephant ears, birds-of-paradise, begonias, impatiens, philodendron and gingers, may be pruned away back to living tissue. This pruning is optional, and is done more to neaten things up than to benefit the plants. However, if the damaged tissue is oozy, mushy, slimy and foul smelling, it should be removed.


You may remove the damaged foliage from banana trees but do not cut back the trunk unless you can tell for sure that it has been killed. It will look brown, feel mushy, feel loose in the soil and will bleed a lot if punctured. The exception would be any banana trees that produced a bunch of fruit the past year. They will not send up any more new growth, and should be cut to the ground to make room for new shoots that will come up in summer.


Generally, it's a good idea to delay hard pruning of woody tropical plants, such as hibiscus, tibouchina, angel trumpet, croton, ixora, schefflera, copper plant and rubber tree, until new growth begins in the spring and you can more accurately determine which parts are alive and what is dead. Dead leaves on woody tropical plants can be picked off to make things look neater. If you can clearly determine what branches are dead on a woody plant you can prune them back. Try scratching the bark with your thumbnail. If the tissue underneath is green, it's still alive. If the tissue is tan or brown the branch is dead. Start at the top and work your way down to see how far back the plant was killed.


Tropical and sub-tropical plants can be used effectively in the landscape, but they must be protected or replaced when necessary. The best idea is to plant a good combination of tender and hardy plants, so that your landscape is not totally devastated in the event of extremely cold weather

Chariton, IA(Zone 5b)

I'd love to move to a warmer climate. Tomorrow night we should hit 38 and then we are going to have night temps in the 60's again. Strange weather, but as long as my plants survive it, I'm okay with it.

Alvin, TX(Zone 9a)

Well Brugie - wanna trade? We're getting a tropical storm here right now ... grrr!! As much as 15 inches of rain all in a few hours are predicted to come down, although you never really know.

Bluffton, SC(Zone 9a)

ugh lucky! that would put us out of drought! we only had one so far

Desoto, TX(Zone 8a)

Amanda, Where is Alvin?

Alvin, TX(Zone 9a)

Well, if you want, I'm sure we can mail you all our water! GLADLY!!!! ;) I'm sorry to hear you guys haven't been getting much rain. It does help with the plants, but the way we get it here sometimes is insane. And a lot of people who aren't from our country and have just ventured over have not a clue how to drive in the water, so they make rash decisions like driving their Pintos through 4 feet of standing water. I'm guessing they think they will float?

Alvin, TX(Zone 9a)

It is about 20 minutes south of Houston and about 30 minutes northwest-ish of Galveston.

Desoto, TX(Zone 8a)

Got it! We, too have been having flash floods and don't anyone really and truly knows how to handle them. My rule is....water on the road....back up...turn around...whatever...just don't try to go through it. Very, very little flowing water takes an auto off the road. I'm not ready to go.....much less drown in such a tragic way.

Alvin, TX(Zone 9a)

See Lou - you and I think alike! I drive a small car. You can BET I'm not going through anything more than an inch! :) If I can't clearly see the ground, nuh uh!!

Desoto, TX(Zone 8a)

I drive a Honda....nuff said....

Alvin, TX(Zone 9a)

Ha ha, "nuff said."

Bluffton, SC(Zone 9a)

lol amanda... i love that humor! floating pintos! we got a tad bit of rain... just a lil bitty bit...

Desoto, TX(Zone 8a)

truly wish you have more rain......just be sensible and careful........we don't want to loose ANY DGers.......under any circumstances....got it...

Eau Claire, WI(Zone 4a)

I got lucky on the rain here. I'm in the border region between northern Wisconsin, which is in severe drought, and southern Wisconsin, where they got over 14" of rain in two days in late August. (Not quite what you've been having in Texas, but look how far from the ocean we are...) After getting no rain at all between early July and mind August we got only 6" from the big storm.

If you look at the Palmer Drought Severity map on weather.com, there is a part of wisconsin where "Extremely Dry" meets "Unusually Moist" (two weeks ago it was adjacent regions of "Extremely Dry" and "Extremely Moist"). Guess this shows just how weird the weather up here has been this year.

Desoto, TX(Zone 8a)

None of our weather patterns have made any sense......but what is sense? Only been keeping records for approx. 120 years....how does that relate to the history of our mother earth?

Buffalo, TX(Zone 8b)

We had a drought here for two years in a row. It got so bad DH sold his cattle along with a lot of other guys around here. Well the drought has broken and the floodgates have opened. We had record breaking rain here for all of the spring and summer.
You could't buy hay before because no one could get it to grow without the rain. This year the hay is up to the cows bellies (DH bought more on a gamble last winter). The problem this year has been in getting a few good days in a row to cut the hay. Most years you get two or three cuttings. This year most people are only getting one cutting. It is better than the drought though at least the hay in the pastures is great for summer grazing.
DH always says if we can pipe oil all over the country why not pipe flood water to drought areas?
Charlene

Emory, TX(Zone 8a)

Here is a link to a product that I just read about today. Just ONE of its many benefits is that it helps to protect against frost/ freeze.

http://www.polymerag.com/tests.htm

Here is a link to the thread that led quite a few people to purchase it today. It is not expensive in my opinion and especialy considering all it does!

http://davesgarden.com/community/forums/t/770336/

I am planning to use it on a lot of things. I can't wait till I recieve it. I think if a plant were sprayed with this product (must be applied long enough before the frost to dry completely) and also covered with a tent as described above and using lights for heat that it would provide a great deal of protection. I plan to use it on plants in the greenhouse also in case the electricity goes off during a freeze. Last year only one night got to about 18* and my heater was not set high enough to keep temps above freezing. A lot of plants were damaged and I even lost a prized elephant ear. It only got down to about 30* in the greenhouse, but if I had the Anti Stress 2000 there is not doubt in my mind all would have been fine, as it alone provides up to 8* protection. Sounds like I am doing an info-mercial on this, but I was so impressed with this product if I could I would do cartwheels! I really only wanted it for the protection from mites an aphids in the beginning. I mean that is wahat casught my eye, because I have brugs that have had them all spring and summer. And I have had spider mites toward the end of winter in the greenhouse and a few plats with aphids this summer. This will prevent that problem also. And more. Sorry about the long post, but I wanted to share this good news.

Carol

Dublin, CA(Zone 9a)

If you can't find the Anti Stress, there are 2 other anti-transpirants that I'm aware of called Wilt Pruf and Cloud Cover, these all basically work the same way.

Emory, TX(Zone 8a)

The do, however some have said the anti stress 2000 is better. I know the concentrate is more "concentrated" in other words it will go further. But anyway some have said it is a superior product. I talked to the owner at length when I order it on the phone and he was very nice and helpfull. Answered every question I could think of...

Northern California, CA(Zone 9b)

I am always so sad to see the time when people are getting ready to put their plants to bed for the winter. Seems like spring started just yesterday. I have till mid November usually till I need to worry but still, the end is coming.

Charlenesplants thanks for your great article. It is so devastating when you live where most tropicals make it thru each winter then you get a cold one and you lose so many of your plants. We had a bad one last year. I sure hope this year will be much better.

(Zone 9a)

The Old Farmer's Almanac predicts this will be the warmest winter in 100 years. That is a real double edged sword as the plants are just not ready when we do get a cold snap and they suffer. My hibiscus' never died last year but they did have a significant enough setback when the cold stunned all their new growth.

Kansas City (Joyce), MO(Zone 5a)

Ok, I know you guys think 40 is nice, but very shortly it will be way below that and I am turning green with envy. Use to live in San Antonio and I want more summer here. It is so sad to see winter coming, altho I guess it is nice to rest, read the plant catalogs, and get ready for spring. Gosh, who would want to garden 10, 11, 12 months a year? ME! lol.....

Last year was my first year on DG and was shocked to see people plant swapping long before I even had anything thinking about popping up, only to be hit by 17 degree weather after it popped up (my roses oh my roses).

Thanks everyone.....

Northern California, CA(Zone 9b)

Last night I was talking to a Daver in Mass and she laughed when I said it was cold here at 40. I do not envy you in 5a Happgarden. Even though my season goes from March to Nov, I still do not get my stuff done. You must be so organized to get all you can out of your short season.

Alice, what zone are you in?

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