Effectiveness of artificial Breeze for frost protection

[bovine421]

Thursday morning I was out of ideas and resources so I took a house fan and put it on my sweet tart. After taking a long nap from gardening. I asked my Google Assistant if I could use a fan for frost protection. Apparently they do in Texas. From my initial reading they said put it on the lowest setting because too much can be counterproductive. So I've been contemplating on ways on how I could incorporate this into my Frost protection procedures. I was thinking once a tree kind of gets too big to cover with frost blankets. Would incandescent large Christmas lights and a shop pedestal fan pointed upwards have any beneficial effect?
I would really like to hear if anyone has any thoughts or ideas on this subject

[fruitnut1944]

The fans only work if there is an inversion and the fan is strong enough to pull down the warm air. An inversion is when it's warmer with increasing elevation. It occurs on a cold still night. The air 30ft up may be several degrees warmer than at the surface. A strong fan can push that warm air down to the surface.

What's worked for me is a heat source around the tree and a covering over that.

[Galatians522]

Many years ago they used giant fans to protect the commercial orange groves around here. They looked like the wind mills that generate electric power out west and you can still see them in a few old groves. As mentioned, they only worked under certain conditions and fell out of favor about the time microjet irrigation became common. After many years of trying different methods of frost protection, I have concluded that water is the easiest. Many years ago (when I was young and foolish) I used open fire and a fan to direct the heat into the tree canopy. It worked ok, except that I had to sleep out there so I could stoke the fire every couple hours. I should say that it worked ok until I caught some leaf litter under the tree on fire and awoke to a blazing inferno. I got the fire put out before it spread very far or did too much damage to my tree, but that was the end of that method of frost protection. 

If you can afford a shallow well and some microjet sprinklers, that is the easiest means of frost protection that I have found. Often, people do not think that it will work,but it does. In an experiment that a friend did with pineapples, plants that were iced experienced less cold damage than plants that were covered. You turn the water on at 35 or 36 and go to bed. In the morning you turn it off when it has melted the ice off the tree. It is also cheaper than running a lot of incandescent bulbs and fans.

The University of Florida has some very helpful info out there about how much water it takes to protect certain crops from freezing based on the temperature and wind conditions. Since peach blossoms freeze at about the same temperature as Mango and Lychee it is highly applicable.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://hos.ifas.ufl.edu/stonefruit/production/frost-protection/%23:~:text%3DPeach%2520flower%2520buds%2520that%2520have,protection%2520can%2520prevent%2520such%2520damage.&ved=2ahUKEwjJ4vu94dbuAhWwwVkKHQQQBVEQFjABegQIAhAE&usg=AOvVaw3yjUITjkx8txRJIbfpgYWT

[C24mccain]

I've pondered the use of a fan as well. In my case my mangoes have gotten to big to cover. The big freezes we had a few years ago I used burn barrels to save them but now they are even bigger. I have pondered using a fan to direct hot air from a burn barrel into the tree because most of the heat is lost going straight up. I assume a properly placed fan could blow the heat into the tree and protect the higher areas. I haven't quite figured out how I would do it but I may experiment with it someday. I would probably only do it if temps were going to be under 29 for 3-4 hours or more. Using burn barrels is a good amount of work and you could be up most of not all night but I think it's worth it on the rare once or twice severe cold event we get every few years. I also have some smudge pots but I haven't had to use them yet other than tests. Need to figure out how to suspend a fan 5-7 feet off ground that will blow air over the burn barrel pushing the heat into the tree. The fan would be a few feet away from the barrel so you would have: fan, space, barrel, space, tree. Maybe the fan could go between the barrel and tree sucking the warm air into the tree? Not sure. I don't think the fan alone would be enough, a heat source is probably needed. I'll attach some videos I have from the freeze we had a few years ago as well as a test I did with a smudge pot a while back and a shower setup over my jackfruit tree. Maybe it will generate some ideas.

https://youtu.be/EJ6-mF9z73Y 2018 freeze, burn barrels

https://youtu.be/tSk72hiqufo smudge pot

https://youtu.be/cRIk16Z7970 shower

[C24mccain]

Many years ago they used giant fans to protect the commercial orange groves around here. They looked like the wind mills that generate electric power out west and you can still see them in a few old groves. As mentioned, they only worked under certain conditions and fell out of favor about the time microjet irrigation became common. After many years of trying different methods of frost protection, I have concluded that water is the easiest. Many years ago (when I was young and foolish) I used open fire and a fan to direct the heat into the tree canopy. It worked ok, except that I had to sleep out there so I could stoke the fire every couple hours. I should say that it worked ok until I caught some leaf litter under the tree on fire and awoke to a blazing inferno. I got the fire put out before it spread very far or did too much damage to my tree, but that was the end of that method of frost protection. 

If you can afford a shallow well and some microjet sprinklers, that is the easiest means of frost protection that I have found. Often, people do not think that it will work,but it does. In an experiment that a friend did with pineapples, plants that were iced experienced less cold damage than plants that were covered. You turn the water on at 35 or 36 and go to bed. In the morning you turn it off when it has melted the ice off the tree. It is also cheaper than running a lot of incandescent bulbs and fans.

The University of Florida has some very helpful info out there about how much water it takes to protect certain crops from freezing based on the temperature and wind conditions. Since peach blossoms freeze at about the same temperature as Mango and Lychee it is highly applicable.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://hos.ifas.ufl.edu/stonefruit/production/frost-protection/%23:~:text%3DPeach%2520flower%2520buds%2520that%2520have,protection%2520can%2520prevent%2520such%2520damage.&ved=2ahUKEwjJ4vu94dbuAhWwwVkKHQQQBVEQFjABegQIAhAE&usg=AOvVaw3yjUITjkx8txRJIbfpgYWT

In my use of burn barrels a few years ago I was afraid of fire so I kept a hose with me and watered the ground every couple of hours. I would sometimes snooze for about 45 minutes but I used my alarm to wake me up as I had to add wood to burn barrels. Obviously using fire is risky and anyone doing so should take precautions.

[Galatians522]

Sounds like you had a much better plan than I did. Of course, my excuse is that I was only 16 at the time.

Ice is very safe and effective for some tropicals (obviously not going to work for Soursop and other ultra tropicalss). When we have all our pumps running, the temperature of the property can rise 3 degrees in 30 minutes even away from where the water is being applied. It does have some limitations and reqires an initial investment, but irrigation in the dry season and a good nights sleep in the winter are well worth it in my opinion.

[C24mccain]

Sounds like you had a much better plan than I did. Of course, my excuse is that I was only 16 at the time.

Ice is very safe and effective for some tropicals (obviously not going to work for Soursop and other ultra tropicalss). When we have all our pumps running, the temperature of the property can rise 3 degrees in 30 minutes even away from where the water is being applied. It does have some limitations and reqires an initial investment, but irrigation in the dry season and a good nights sleep in the winter are well worth it in my opinion.

I have pondered an overhead irrigation system for protection but haven't really looked into it other than the one shower I created over a jackfruit tree. I wonder if I could create something with a water pump I put in my pond and  use to irrigate my trees? It puts out 3000 gallons an hour which I assume is way more than I would need. I'm going to do some investigating on this as it may be something I could setup for next year.

[Jagmanjoe]

Sounds like you had a much better plan than I did. Of course, my excuse is that I was only 16 at the time.

Ice is very safe and effective for some tropicals (obviously not going to work for Soursop and other ultra tropicalss). When we have all our pumps running, the temperature of the property can rise 3 degrees in 30 minutes even away from where the water is being applied. It does have some limitations and reqires an initial investment, but irrigation in the dry season and a good nights sleep in the winter are well worth it in my opinion.

I have pondered an overhead irrigation system for protection but haven't really looked into it other than the one shower I created over a jackfruit tree. I wonder if I could create something with a water pump I put in my pond and  use to irrigate my trees? It puts out 3000 gallons an hour which I assume is way more than I would need. I'm going to do some investigating on this as it may be something I could setup for next year.

While the idea you have using pond water may have merit on the surface, mccain be sure to think it through.  Is the pond water treated, even around the shoreline for vegetation or anything else?  What is the source of that pond water and could anything be leaching into it that might prove harmful to your trees in the long run?

I am sure you are probably already considering these potential factors but for any that are just starting to read it with a light bulb coming on, think it through all the way.  While we have a pond that we share with a neighbor, I would feel safer setting up a system with efficient spray heads above  the trees and using my well water with a stable temperature as opposed to stratified varying temperatures from a pond.

While we do have several nurseries around here that have ponds they use for their plants, I believe they would draw considerably more water and are probably more regulated like strawberry fields by government agencies relative to pumping well water from our aquifer.

Just my initial thoughts

[C24mccain]

Our pond is just on our fenced in property. I don't use any chemicals to get in it. In fact I water my fruit trees with during the dry season from February to May. However the temperature of the pond water maybe colder than well water that time of year so I'd have to see how that might effect the situation. There is also a potential issue of clogging from dirty water which would be real bad. I might be able to use our well water. I'll have to see if it puts out enough gph. It's probably something like 300 gallons per hour but I would probably only setup overhead irrigation for the mangoes. The tougher trees Im not as worried about although you never know when we will get hit by a 25* night or lower. Things to ponder.

[bovine421]

I've pondered the use of a fan as well. In my case my mangoes have gotten to big to cover. The big freezes we had a few years ago I used burn barrels to save them but now they are even bigger. I have pondered using a fan to direct hot air from a burn barrel into the tree because most of the heat is lost going straight up. I assume a properly placed fan could blow the heat into the tree and protect the higher areas. I haven't quite figured out how I would do it but I may experiment with it someday. I would probably only do it if temps were going to be under 29 for 3-4 hours or more. Using burn barrels is a good amount of work and you could be up most of not all night but I think it's worth it on the rare once or twice severe cold event we get every few years. I also have some smudge pots but I haven't had to use them yet other than tests. Need to figure out how to suspend a fan 5-7 feet off ground that will blow air over the burn barrel pushing the heat into the tree. The fan would be a few feet away from the barrel so you would have: fan, space, barrel, space, tree. Maybe the fan could go between the barrel and tree sucking the warm air into the tree? Not sure. I don't think the fan alone would be enough, a heat source is probably needed. I'll attach some videos I have from the freeze we had a few years ago as well as a test I did with a smudge pot a while back and a shower setup over my jackfruit tree. Maybe it will generate some ideas.

https://youtu.be/EJ6-mF9z73Y 2018 freeze, burn barrels

https://youtu.be/tSk72hiqufo smudge pot

https://youtu.be/cRIk16Z7970 shower

I think I may have to do something like what was in your last video the micro jet sprinkler jet shower system. That does seem to be the easiest route since I have two other mango giganticus varieties. Here is a couple other ideas I was kicking around

[Jagmanjoe]

Our pond is just on our fenced in property. I don't use any chemicals to get in it. In fact I water my fruit trees with during the dry season from February to May. However the temperature of the pond water maybe colder than well water that time of year so I'd have to see how that might effect the situation. There is also a potential issue of clogging from dirty water which would be real bad. I might be able to use our well water. I'll have to see if it puts out enough gph. It's probably something like 300 gallons per hour but I would probably only setup overhead irrigation for the mangoes. The tougher trees Im not as worried about although you never know when we will get hit by a 25* night or lower. Things to ponder.

With regard to your concern about clogging from dirty water, I recall seeing something where a pump had a filter attached to it and a small portion of the water being pumped was jetted back at the filter portion to help keep the water flowing overall.  You might want to check into something like that.  Also, many years ago when I had another property that was on a lake, I rigged up a system where I had the pump inside a large bucket so the pump would not pull directly from the sediment at the bottom of the pond.  I then used a medium screening over the top of the bucket with a hole for the pipe coming out while covering the rest of the bucket to keep larger debris from even getting to the pump itself.  The pump I used was referred to as a trash pump which was designed to be able to handle some smaller sediment that got through without burning up.  Just relaying what worked for me.

[Galatians522]

Sounds like you had a much better plan than I did. Of course, my excuse is that I was only 16 at the time.

Ice is very safe and effective for some tropicals (obviously not going to work for Soursop and other ultra tropicalss). When we have all our pumps running, the temperature of the property can rise 3 degrees in 30 minutes even away from where the water is being applied. It does have some limitations and reqires an initial investment, but irrigation in the dry season and a good nights sleep in the winter are well worth it in my opinion.

I have pondered an overhead irrigation system for protection but haven't really looked into it other than the one shower I created over a jackfruit tree. I wonder if I could create something with a water pump I put in my pond and  use to irrigate my trees? It puts out 3000 gallons an hour which I assume is way more than I would need. I'm going to do some investigating on this as it may be something I could setup for next year.

Yes, it will work with pond water. A huge portion of the "latent heat" comes from the formation of the ice. Pond water is in the 55 degree range in this part of the state durring winter and well water is about 68-70. So, there is about a 15 degree difference. We use both and they protect the trees equally. The only difference is that there is a little more ice formation with the pond water. Greater ice formation can lead to limb breakage if it become excessive, especially on poorly trained trees with narrow crotch angles. There can be more cloggs with the pond water, but this is usually mitigated with a filter on the main line. Regardless of the water source, imitters will clog as the system ages and algae forms in the lines. As a result, checking for clogged imitters is a normal part of growing the tree.

The only concern I can think of with using pond water is if you are protecting "bearing trees" (or trees with ripe or soon to be ripe fruit on them). This should never be a concern for lychee or mango, but might be worth considering if you are also protecting jujubee or loquat with overhead irrigation. In that case the water would likely need to be tested for biological pathogens such as E. coli.

Also, some what counterintuitively, water management often has fewer regulations on pond water usage than well water in commercial settings because pond water is considered recycled. This obviously does not apply to natural water sources such as pumping out of a river or lake which often requires special permitting from the governing agency.

[C24mccain]

Jagmanjoe, the pump I put in the pond is also in a bucket just as you mentioned but thanks for the idea of putting a filter screen on top as I had not done that.

[C24mccain]

Thanks Galatians, I'll remember a filter for the main line. Probably only going to build a irrigation setup for my mangoes. We'll see.

[Galatians522]

Thanks Galatians, I'll remember a filter for the main line. Probably only going to build a irrigation setup for my mangoes. We'll see.

Good thinking, its better to "over protect" a few trees than to try to under protect everything.

[bovine421]

Many years ago they used giant fans to protect the commercial orange groves around here. They looked like the wind mills that generate electric power out west and you can still see them in a few old groves. As mentioned, they only worked under certain conditions and fell out of favor about the time microjet irrigation became common. After many years of trying different methods of frost protection, I have concluded that water is the easiest. Many years ago (when I was young and foolish) I used open fire and a fan to direct the heat into the tree canopy. It worked ok, except that I had to sleep out there so I could stoke the fire every couple hours. I should say that it worked ok until I caught some leaf litter under the tree on fire and awoke to a blazing inferno. I got the fire put out before it spread very far or did too much damage to my tree, but that was the end of that method of frost protection. 

If you can afford a shallow well and some microjet sprinklers, that is the easiest means of frost protection that I have found. Often, people do not think that it will work,but it does. In an experiment that a friend did with pineapples, plants that were iced experienced less cold damage than plants that were covered. You turn the water on at 35 or 36 and go to bed. In the morning you turn it off when it has melted the ice off the tree. It is also cheaper than running a lot of incandescent bulbs and fans.

The University of Florida has some very helpful info out there about how much water it takes to protect certain crops from freezing based on the temperature and wind conditions. Since peach blossoms freeze at about the same temperature as Mango and Lychee it is highly applicable.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://hos.ifas.ufl.edu/stonefruit/production/frost-protection/%23:~:text%3DPeach%2520flower%2520buds%2520that%2520have,protection%2520can%2520prevent%2520such%2520damage.&ved=2ahUKEwjJ4vu94dbuAhWwwVkKHQQQBVEQFjABegQIAhAE&usg=AOvVaw3yjUITjkx8txRJIbfpgYWT

Thank you for sharing your experience. Would one micro jet sprinkler like this  running up through the center of the tree and above It by a couple of feet suffice. I would like to be able to Frost protect a 12 x 12 mango trees flowers. Any help or recommendations would be appreciated
https://youtu.be/64XTm9FEG1U

[Galatians522]

Those are mini-wobblers. They work good, too. We have them in part of the grove. Ours are set about 2/3 to 3/4 of the way up the tree. The heat rises from there and typically protects the top of the tree. Ice on the interior framework does not tend to break the tree down, but if you go truly overhead the risk of breakage increases. I can't recall a time when we iced open mango or lychee flowers, but I will ask my Dad. In close to 20 years we have only lost one bloom on our early lychee varieties using water for protection.

[nattyfroootz]

The idea with the big fans in orange groves and such is that the air above the plant area is much warmer than it is close to the ground and within the plant canopy where air may stangnant and cool air will settle.  It's definitely an interesting idea but I do think the microjet Frost Protection irrigation options are probably the most efficient and best options on a larger scale.  Small heat fans and forced air heaters might be a good idea. 

[bovine421]

Those are mini-wobblers. They work good, too. We have them in part of the grove. Ours are set about 2/3 to 3/4 of the way up the tree. The heat rises from there and typically protects the top of the tree. Ice on the interior framework does not tend to break the tree down, but if you go truly overhead the risk of breakage increases. I can't recall a time when we iced open mango or lychee flowers, but I will ask my Dad. In close to 20 years we have only lost one bloom on our early lychee varieties using water for protection.

This is my first rodeo on this so I really don't know what I'm doing but I found a pressure chart template they're color-coded the lime one at 40 pounds pressure has a flow rate of 2 gallons per minute all the other colors or much more than that. I'm thinking I can turn the pressure down to maybe 30 or less too lower the flow rate. What I can't figure out is what diameter it will cover at those lower rates. I have no loyalty to this product I just stumbled across it. If you can recommend something it would be appreciated. Basically I just want to run a stick of PVC up the Center of tree 3/4 the way as you suggested  I want to be able to hook a garden hose to it and regulate the pressure at the faucet valve. Something very simplistic. Because I'd only be using it during Frost and freeze situations which hopefully is not more than two or three times in a season

Ps I found some lime colored mini wobblers so I'm going to order to experiment but still would like to hear your recommendations

[Galatians522]

I can't say that I could recommend any particular brand of mini-wobbler over another. The larger the area covered by the spray and the finer the mist the better because there will be more heat exchange. We have even duct taped a poly pipe line to the tree with microjet heads tapped dirrectly into the line at intervals. It was not pretty, but it was cost effective, fast, and got the job done.

[Jagmanjoe]

If you are going to run a pipe up the tree, first I would consider using plastic EMT as opposed to plumbing PVC.  My reasoning for this is that plumbing PVC gets brittle over time in the sun and the plastic electrical conduit, while being the same size, is manufactured with UV inhibitors that should hold the stability being out there year round.

Also, to hold it in place with established trees, I would suggest using double sided velcro.  As a center pole for my frost covers when I planted my trees (not a grove but I did plant a dozen smaller mango trees over the past year) I drove a piece of chain link fence top rail into the ground to use as the main support for my frost cover but also to stabilize the young trees and temporarily pull branches in closer when I cover the trees.  I use the softer side of the velcro against the tree trunk and branches and just twist it as necessary to adhere it to itself.  It holds extremely well, is very easily adjustable and does not harm the tree.  It could easily hold the water pipe in place for you without damaging the tree trunk or any branches.

As a side note, the reasoning for the fence top rail is that it is galvanized so it is more resistant to rust and there are a couple of ways to increase its height as the tree grows plus my conduit top cross supports for the frost covers will easily slip on and off.  That would be a different topic though.

[bovine421]

I can't say that I could recommend any particular brand of mini-wobbler over another. The larger the area covered by the spray and the finer the mist the better because there will be more heat exchange. We have even duct taped a poly pipe line to the tree with microjet heads tapped dirrectly into the line at intervals. It was not pretty, but it was cost effective, fast, and got the job done.

Yeah I'm trying to decipher this color chart do you see any particular color that catches your eye? I may buy variety pack and experiment.
 

[bovine421]

If you are going to run a pipe up the tree, first I would consider using plastic EMT as opposed to plumbing PVC.  My reasoning for this is that plumbing PVC gets brittle over time in the sun and the plastic electrical conduit, while being the same size, is manufactured with UV inhibitors that should hold the stability being out there year round.

Also, to hold it in place with established trees, I would suggest using double sided velcro.  As a center pole for my frost covers when I planted my trees (not a grove but I did plant a dozen smaller mango trees over the past year) I drove a piece of chain link fence top rail into the ground to use as the main support for my frost cover but also to stabilize the young trees and temporarily pull branches in closer when I cover the trees.  I use the softer side of the velcro against the tree trunk and branches and just twist it as necessary to adhere it to itself.  It holds extremely well, is very easily adjustable and does not harm the tree.  It could easily hold the water pipe in place for you without damaging the tree trunk or any branches.

As a side note, the reasoning for the fence top rail is that it is galvanized so it is more resistant to rust and there are a couple of ways to increase its height as the tree grows plus my conduit top cross supports for the frost covers will easily slip on and off.  That would be a different topic though.

Thanks for the info on the conduit will do.  The chain link fence top rail  come in Long sections and I may know where there's some laying around thanks

[Triloba Tracker]

Some folks use helicopters

[bovine421]

Some folks use helicopters

You know I would have never thought of that but I was wondering if anyone in Polk County has used their airboat.