Whats up mangodude!
When I was into tropicla birds my vet told me that I should buy a heat lamp for reptiles. The vet said that it puts out heat to simulate the uv rays from the sun. Maybe that light would help warm the mango? I'm in no way saying saying you should try this but maybe it would help?
Andrew

Hi mangodude:
I live in fl/jax and I have some very tropical things here with good success. Of course, I lived and learned like all of us...

Remember, this is just what I do! Please, don't be mad at me if your plants die or your house catches on fire...

About Christmas lights: Be very careful if you use them. The only two plants I have lost died because the Christmas lights over-heated the trunk and killed my guava about 6 inches from the ground. I had wrapped the lights on the trunk and covered it with a blanket, you should not do that... So, I just use warm water and infrared heat lamps now.

Here is what I have done to keep my mango, keylime, guava, and others alive:

1. If potted: I just bring them in the garage (no extra heat needed).
2. Planted in ground but small: place a large bucket (5gl) of warm water right next to the trunk and cover plant with a sheet and then a blanket.
3. If planted but large: I use two large buckets of warm water next to the trunk plus one or two 250W infrared heat lamps placed on the ground looking up toward the canopy. Also, you must cover the tree for the method to work.
4. If planted but very large: keep adding more heat lamps or more heat sources until you feel it is ok.

The methods above I use when it is a tender plant. For other plants (E.G. oranges) often you can just place hot water and/or heat lamps under the tree and not cover it and it will be fine. It all depends on the minimum expected temperature, check the NWS forecast right before you go to bed the night of the freeze to make sure that your protection is sufficient.

*** Important ***

To succeed you have to use your common sense. If you heat your plants too much they will die or cause a fire. If you do it properly, they will make it through the freeze without any problems... Here are some tips for making the above methods actually work:

1. Only cover your plants when needed. If the temps are dropping close to a point of danger, lets say 33f for the mango, I do nothing to protect it. I believe that they will become hardier if allowed to come close to dangerous temperatures. If the NWS was wrong and it drops to 30F, then you get minor damage, so what, it will recover. Of course, when plants are very small I tend to protect them a little more...

2. Common sense measures: Stick your hand under the tree (where the heat source points) and feel the heat. If it feels to hot (hotter than the sun) than it probably is too hot and/or too close to the plant...

3. Do not use more heat than its needed: I have a $10 wireless thermometer that I stick inside the tree canopy to check the effect of my heating and covering on the temperature. You will get better at it as time goes on, I hardly ever use my thermometer any more.

4. Experiment before the freeze comes: Make sure you have what you need to cover and/or heat the tree. Remember, the cover should go all the way to the ground and be firmly secured in place.

5. It can be done: It sounds hard, but really it is about experience and instinct.

I have a very tender keylime tree here in Jacksonville that has grown from 1ft to 8 ft high and produces hundreds of limes without ever having a problem with a freeze. Of course, I protected when necessary, which frankly is not very often. I even pick limes in the winter...

Good luck!

Hi again mangodude:
Yeah, reasonably priced infrared heat lamps are not easy to find. Really what makes it hard is that you need a lamp that can handle shock and water, but you don't want to break the bank in the process! I got my lamps from amazon and they have worked great for me. I have not been able to find better/more-affordable lamps anywhere...

Here is the name of the lamps and the link to the relevant amazon page:

Brand: Petsakes
Lamp model: Infra Heat Lamp - Hr 02 250w
link: http://www.amazon.com/gp/product/B000LZ2D1S

If for some reason the link does not work, just search for the lamp using the amazon search... Usually, I look for heat lamps in the pet products because reptiles need heat sources, so heat lamps for them are common, reasonably priced and tough...

Good luck again...

Here is a link that might be useful: Infra Heat Lamp - Hr 02 250w

Mostro,

Thanks a lot for that very helpful and detailed directions
on how you protect your tropical trees. May I ask...using the warm water method, so the water in the pail(what type do you use,btw?) doesn't get cold in a couple of hours? Just wondering because it sounds like a very good and safe way to protect them, but just wanted to know how long the warm water stays warm longer? Maybe the infrared lights in conjunction keeps the water warm? Thanks for the help...appreciate the link for the lamp too!

Hello puglvr1:

What type of container?
Really I use whatever type of large container I have. For example, 5 gallon paint buckets, 5 gallon water jugs, trash cans, whatever is big enough for the job...

Does it get cold in a couple of hours?
Yes and no. It really depends on the minimum temperature you are expecting the night of the freeze, the amount of water used and the size of the tree. I only use the water-only method for small trees and I cover them very well with a thick blanket to prevent heat lost. Of course, I replace the warm water in the buckets right before I go to bed the night of the freeze. I want to be clear, I cover the tree (bucket and all) all the way to the ground...

why warm water and infrared lights together?
The main reason I like to use water and heat lamps together is that if there is a problem with the lamps (E.G. electrical failure, burnt out light, etc) the warm water will serve as a backup and hopefully save the tree. At the very least, the buckets placed up against the trunk should prevent the trunk from freezing and your tree should recover eventually. A second reason is that when you add the warm water to the setup, you can use less electrical power to do the same job, and it keeps the humidity in the tree canopy higher which is probably a good thing for several reasons...

Water temperature?
I use water that is around 120F (50C, not more. Increasing the water temperature beyond 50C is probably not wise, because you run into over-heating problems and your trees could be damaged. It is always safer to use more water than hotter water...

Why do I like using this water thing?
Yes, it is very safe, easy, and cheep. However, it takes practice to get it just right, a thermometer will be your best learning tool...

Thanks Mostro :o) Appreciate it!!