Washingtonia in zone 7a with just wrapping?

[siege2050]

I originally started some Washingtonia Filibusta seeds to grow in containers (Still waiting on Filifera to germinate). But after seeing how fast they are growing for me, and looking around the web, is it possible to protect a Washingtonia with just wrapping the trunks heavily in a zone 7a down to 0F? I am not too crazy about making mini greenhouses so would prefer to wrap. If so what kind of wrapping, would heat tape be necessary on the coldest nights with a thermostat? Also if I remove all the fronds, will new ones grow back in time to make the palm look okay each year? What is the cold hardiness for Filibusta as compared to Robusta, and Filifera and is it increased a lot by keeping the palm dry with plastic over the wrapping for all three? I grow a tropical garden here in Oklahoma and need palms that grow decently fast, and am willing to use them as sort of a long term annual, replacing later with newer ones as they get too tall to protect. I am seeing 18 degrees for Robusta, and 10 for Filifera a lot on different sites, is Filibusta somewhere in between?

[Brad Mondel]

Here's the deal, if the soil freezes then your washy will be a goner. You will have to keep a heavy load of mulch to protect the root zone from this. Also, your soil must have perfect drainage or it will hold too much moisture and freeze your palm into an ice pop. 

On the bright side my Washingtonia robusta in zone 8b defoliated every winter but recovered a full crown by fall. They grow fast! And should recover quickly as long as they have enough heat and sunshine. 

Keep them as dry as possible, the dryer it is the more cold hardy they are. You can wrap the trunk and crown well with burlap and provide a barrier for moisture such as plastic sheeting. You can also add Christmas lights or heat tape during your coldest nights with a thermocube. 

[NorCalKing]

I don't think they stand a chance there unfortunately, from everything I've seen and read - zone 8A min, and even then it's recommended with protection. But, that's what zone pushing is all about.

[siege2050]

36 minutes ago, NorCalKing said:

I don't think they stand a chance there unfortunately, from everything I've seen and read - zone 8A min, and even then it's recommended with protection. But, that's what zone pushing is all about.

It can be done, I have seen a few successful stories like these in zone 6B of course with a small house built over them. I may have to just accept that I will have to build a structure over them, but would like to just wrap with heating cable, etc. under the wrapping if possible.

http://home.ptd.net/~mishele/webpage/washy1.htm

[_Rob_]

There is quite a few doing OK in our neck of the Woods (i have one in 4th winter now in a wet 8a at best), and i believe it can be done down to -15°. If Trachycarpus is fine without protection in your area, you can try.

The way i do it is this:

• I basically tie all foliage together (protecting the spear), and wrap in bamboomat (betther than the straw ones), 2 layers round.
• Inside i mount 6-9 meters of old style Xmas lights - I use only when below 0°. You may add a thermostat but i do the manual switch.
• Place Bucket on top of the bamboo circle - or a massive container when bigger - and fix it, as it will blow off!
• Wrap the whole construction with bubblewrap when heavy frost is expected (below-5°). 2 layers is usually enough.
• Remove plastic above 0° for ventilation.
• In case of very heavy Frosts, protect soil with 2"polystyrene or heavy mulch.

Using this setup i managed at least 5°C above ambient temps inside construction, in some occasions even 10° above when construction is well sealed.

The secret is to not keep lights on all winter as it will give you too much very weak growth killing the palm in spring, and vent when temps allow for it for removing excess moisture. I Leave bucket and bamboo cover around all winter.

Note that im not using burlap or other cloth, as it accumulates water over winter, which is hard to vent out.

One last thing: palms may burn after winter, so unwrap on a cloudy week!

Edited January 25, 2016 by _Rob_

[nitsua0895]

45 minutes ago, _Rob_ said:

There is quite a few doing OK in our neck of the Woods (i have one in 4th winter now in a wet 8a at best), and i believe it can be done down to -15°. If Trachycarpus is fine without protection in your area, you can try.

The way i do it is this:

• I basically tie all foliage together (protecting the spear), and wrap in bamboomat (betther than the straw ones), 2 layers round.
• Inside i mount 6-9 meters of old style Xmas lights - I use only when below 0°. You may add a thermostat but i do the manual switch.
• Place Bucket on top of the bamboo circle - or a massive container when bigger - and fix it, as it will blow off!
• Wrap the whole construction with bubblewrap when heavy frost is expected (below-5°). 2 layers is usually enough.
• Remove plastic above 0° for ventilation.
• In case of very heavy Frosts, protect soil with 2"polystyrene or heavy mulch.

Using this setup i managed at least 5°C above ambient temps inside construction, in some occasions even 10° above when construction is well sealed.

The secret is to not keep lights on all winter as it will give you too much very weak growth killing the palm in spring, and vent when temps allow for it for removing excess moisture. I Leave bucket and bamboo cover around all winter.

Note that im not using burlap or other cloth, as it accumulates water over winter, which is hard to vent out.

One last thing: palms may burn after winter, so unwrap on a cloudy week!

Is there anything that can be done once the W. Robusta or Filifera is too tall to reach the foliage? Because they grow really well here during most years but I'd say one out of ten winters we'll drop below 15F for a night and I've seen tall ones die. 

[Tropicdoc]

So I wrapped my dypsis last night with bubble foil and dropped a strand of 100 Xmas lights into the top of the cylinder of foil and clamped the top. I felt in there with my hand.... It was about 100 degrees inside. I actually partially in clipped the top to let out some heat. I had no idea Xmas lights put off that much heat. Or maybe bubble foil is just awesome for this function. Good thing is that the bubble foil is waterproof too

[TexasColdHardyPalms]

W. Robusta or filbusta won't make it without auxiliary heat in 7a, period, not a chance from what I have seen. Both are a warm 8b/9a palm.  I've had and seen many wrapped robusta die at 13 degrees.

[siege2050]

Well, it looks like I am gonna have to make palm condos lol

[siege2050]

I dig up 100 pound banana stems and drag them under the house each fall, I guess I can do this also lol

[siege2050]

Anybody ever tried one of these adapted to house current with a thermocube? I had to use one one winter in my car, and they can get decently warm

[NorCalKing]

17 hours ago, siege2050 said:

It can be done, I have seen a few successful stories like these in zone 6B of course with a small house built over them. I may have to just accept that I will have to build a structure over them, but would like to just wrap with heating cable, etc. under the wrapping if possible.

http://home.ptd.net/~mishele/webpage/washy1.htm

I love the enclosure. Very cool. But as I said, there's no harm in trying to zone push. Just be aware it mat not make it any given winter without a palm condo :)

[enigma99]

how about some pipe heating cables in the ground just in case you get a bad freeze? hmm

[siege2050]

I will have to figure something out, I like these palm seedlings too much. Maybe line the enclosure with rolls of Mylar (Space Blankets) that you can buy off of ebay, and one of those small cigarette lighter car heaters with a thermocube that will just kick on in the coldest times.

[jwitt]

I and others here(Albuquerque metro) grow filifera here and there are some in zone 6b/7a without protection.  Granted this climate is high elevation(5000') so the air is thin, sun strong and air dry. We do not have the below freezing days like you guys do. Our absolute minimum temperatures are quite cold. Larger palms here have survived -11f, although defoliated. I suggest you direct sow your seeds where you want them to grow, the plans will be much, much stronger. Easy to cover when young. Robusta are a no go here and will succumb after 1-5 years, just too cold, but hybrids and filifera are doable with proper siting. 

One other thing, we don't have the swings  quite like you guys, We don't go from 75 to 20 in 24 hours, although we may go from 50 to 20 for a month or so, daily!  So maybe our palms are in a more "hibernating", non growing state. Just a thought.

Edited January 31, 2016 by jwitt

[TexasColdHardyPalms]

All of my washingtonia continue to grow during the winter. Monday will be the fourth day in a row above 80 then our lows drop to 30 for three days.  The bad winter of 2011 had mid 70s for a few days before we dropped to 14-15f for a few days with heavy ice.  That killed almost all of the robusta and hybrids in the area.

[_Rob_]

On ‎25‎/‎01‎/‎2016‎ ‎02‎:‎31‎:‎32, nitsua0895 said:

Is there anything that can be done once the W. Robusta or Filifera is too tall to reach the foliage? Because they grow really well here during most years but I'd say one out of ten winters we'll drop below 15F for a night and I've seen tall ones die. 

My technique will work as far as your bamboomats stretch...in my case 6' standing hieght - after that we'll need to start building constructions i guess.

Ive already seen 15' heigh builds using heater cables etc with washys here starting to trunk on our dutch forums  

[siege2050]

Finally had Filifera seeds germinate today. This species seems to need more heat to sprout than Robusta, or Filibusta. They just sat there till I put them on top of one of my light fixtures that gets warm, then germinated a few days later. Filibusta and Robusta germinated at Room temp.

[climate change virginia]

would a filbusta survive zone 8a unprotected in a sheltered location that doesn't get rain

Edited October 26, 2020 by climate change virginia

[kinzyjr]

Just now, climate change virginia said:

would a filbusta survive zone 8a unprotected in a sheltered location

In the Desert southwest, most likely yes.  On the east coast, not for very long.

[climate change virginia]

1 minute ago, kinzyjr said:

In the Desert southwest, most likely yes.  On the east coast, not for very long.

oh ok

[Ben OK]

I don't want to come across as telling a lot of people they are wrong, but I've personally seen at least 8 or 10 hybrid washingtonias survive Oklahoma winters wrapped without heat. I am not saying it would work in every 7a area of the world, but it seems to work here pretty frequently. Aside from my own washingtonia (only about 4 ft in total height) that survived my poor wrapping job last winter, and the larger ones I have seen at businesses in the Tulsa area, I have seen pics and heard more anecdotes from other palm growers in this area.

I can't give you a great explanation of the best way to do it, since mine was wrapped poorly last year during the months of January and February only in what was only an 8a winter and I still managed total defoliation. The basic idea I've gotten from others is to provide some layers of wrapping that mostly serve as insulation, covered with something over the insulation layer to keep moisture off of the crown.

I wrapped mine last winter with landscape fabric layers, with a black trash bag tied over it to keep it dry. This year I plan to use more layers of fabric (maybe a moving blanket instead?) and I may wrap a tarp over it as the top layer. I think the trash bag was just so thin that it allowed easy condensation. It probably also got too hot on our nicer winter days.

Again, I'm not saying those who say it won't work are wrong, they may have seen it fail numerous times in their respective locations. I just know it seems to work pretty frequently here when tried. A long time palm grower in Tulsa told me several years ago that he and a friend wrapped one each year until it got too tall for them to take care of. In the pics he showed me, it looked to be about 20 ft in overall height before they had to let it go.  So as long as you see it as a chance to have fun with an out of zone palm for five to ten years, I would say give it a try.

With that said, I would advise you to grow it to a 5 to 7 gallon size in a pot before putting it in the ground. I have had rotten luck getting small washingtonians to survive the winter in the ground. 

[kinzyjr]

2 minutes ago, Ben OK said:

I don't want to come across as telling a lot of people they are wrong, but I've personally seen at least 8 or 10 hybrid washingtonias survive Oklahoma winters wrapped without heat. I am not saying it would work in every 7a area of the world, but it seems to work here pretty frequently. Aside from my own washingtonia (only about 4 ft in total height) that survived my poor wrapping job last winter, and the larger ones I have seen at businesses in the Tulsa area, I have seen pics and heard more anecdotes from other palm growers in this area.

I can't give you a great explanation of the best way to do it, since mine was wrapped poorly last year during the months of January and February only in what was only an 8a winter and I still managed total defoliation. The basic idea I've gotten from others is to provide some layers of wrapping that mostly serve as insulation, covered with something over the insulation layer to keep moisture off of the crown.

I wrapped mine last winter with landscape fabric layers, with a black trash bag tied over it to keep it dry. This year I plan to use more layers of fabric (maybe a moving blanket instead?) and I may wrap a tarp over it as the top layer. I think the trash bag was just so thin that it allowed easy condensation. It probably also got too hot on our nicer winter days.

Again, I'm not saying those who say it won't work are wrong, they may have seen it fail numerous times in their respective locations. I just know it seems to work pretty frequently here when tried. A long time palm grower in Tulsa told me several years ago that he and a friend wrapped one each year until it got too tall for them to take care of. In the pics he showed me, it looked to be about 20 ft in overall height before they had to let it go.  So as long as you see it as a chance to have fun with an out of zone palm for five to ten years, I would say give it a try.

With that said, I would advise you to grow it to a 5 to 7 gallon size in a pot before putting it in the ground. I have had rotten luck getting small washingtonians to survive the winter in the ground. 

I agree that wrapping would help a lot and probably make it work.  Unprotected in Washington DC, I'd say no.  That said, being wrong isn't always a bad thing.

[Ben OK]

3 minutes ago, kinzyjr said:

I agree that wrapping would help a lot and probably make it work.  Unprotected in Washington DC, I'd say no.  That said, being wrong isn't always a bad thing.

I think you're certainly right about that. The moisture alone in a 7a winter east of the Rockies makes freezing and rotting pretty much a sure thing for a washingtonia. Keeping the crown dry is a must...and something I need to get better at if I want mine to survive the coming winter.

[ColdBonsai]

An interesting and kind of similar topic:

 

He managed to grow one for a few years unprotected in an Idaho zone 7a. Not far from me, actually. Keep in mind this area only gets about 11 inches of precipitation a year with fairly dry winters. I think Washington DC gets about 4 times that for comparison.

Also, I wish I knew if that Idaho Washingtonian is still around...

 

Edited October 26, 2020 by ColdBonsai